042042   WANG Y, HUANG C-Y, FU R, ZHANG H (Ophthalmology Dep, Shenyang Forth People’s Hospital, Liaoning ,China, Email: fengshan8282324@163.com) : Preparation and analysis of sodium carboxymethyl cellulose and its effect on xerophthalmia. Indian J Chem Sec A 2020, 59A(09), 1348-53.

Carboxymethyl cellulose (CMC) has been effectively synthesized with high yield and purity. With the prolongation of time after model establishment, the values of Schirmer Ⅰ test (S Ⅰ t) and breakup time of tear film gradually decreased. The α-MSH and CMC alone could ameliorate corneal tissue damage and corneal morphological abnormalities in the dry eye to some extent. However, compared with monotherapy, the treatment of α-MSH combined with CMC has a more significant positive effect on the improvement of tear secretion and the stability of tear film in dry eye model in the early stage after modeling. There are significant differences between the model control group and the normal control group at each time point after model establishment (all P<0.01) at 7^th, 14^th, 21^th and 28^th days after treatment. After 7, 14 and 21 days treatment, the S Ⅰ t values in the α-MSH+CMC treatment group were 4.80±0.79, 4.10±0.52 and 4.30±0.86 mm, respectively.

2 illus, 2 tables, 21 ref

042041   WANG H, ZHU H, QI D, WANG S, SHEN K (Dalian Univ of Technology, Dalian 116023, China, Email: lbrf953510@sina.cn) : Template-free synthesis of hierarchical mesoporous carbon: Based on functional coal tar pitches with carboxylation and diketone structures. Indian J Chem Sec A 2020, 59A(09), 1341-7.

An efficient and easy template-free method for the preparation of hierarchical porous carbons (HPCs) has been developed using low-priced coal tar pitch (CP) as the starting material. Application of the diketone (-COCO-) radical provides a carbonyl methylene group for polycyclic aromatic hydrocarbons by condensation and produces an effective micro-mesoporous network with a high specific surface area. With the help of controlled Friedel-Crafts reaction and oxidation, carboxyl-functionalized CP is obtained as the stratified porous CP precursor, and the high-temperature decarboxylation (>230°C) helped in generating well-developed micro-mesoporous carbon. The total pore volume of porous carbon of 1277.3 and 1.45 cm³g^-1 the maximum BET surface area suggests that the rapid electrolyte ion exchange and charge transportability would be better for the electrochemical capacitor.

5 illus, 2 tables, 21 ref

042038   MURUGAN E, DHAMODHARAN A, POONGAN A, KALPANA K (Physical Chemistry Dep, Madras Univ, Chennai - 600 025, Tamil Nadu, Email: dr.e.murugan@gmail.com) : Electrochemical analysis of nitrite contamination in water using SnTe@GO modified glassy carbon electrode. Indian J Chem Sec A 2020, 59A(09), 1313-20.

An electrochemically active tin telluride (SnTe) decorated graphene oxide (GO) (SnTe@GO) nanocomposite has been synthesized through simple experimental method and used the same for surface modification of glassy carbon electrode, thus developed a new efficient SnTe@GO/GCE which in turn has been demonstrated as a sensor for identification and quantification of nitrite species in water samples. Common analytical techniques are employed and established the physiochemical properties of SnTe@GO nanocomposite. The electrocatalytic activity of SnTe@GO/GCE has been examined towards sensing and quantification of nitrite through Cyclic Voltammetry and Differential Pulse Voltammetry techniques. The obtained results revel that SnTe@GO/GCE exhibited high sensitivity with wide linear range such as 9.8-162 mM and detection limit found to be 0.079 µM. In addition, in order to inspect the real time application of SnTe@GO/GCE, it is also employed and determined the concentration of nitrite in drinking water, pond water and well water samples which are collected from Rayapuram, Muttukadu and Guindy during the specific period. The LOD observed for drinking water collected from Rayapuram, Chennai are 1.63 μM, pond water collected from Muttukadu, Kanchipuram 2.5 μM, and the well water collected from Guindy, Chennai are 1.25 μM, and thus proves that the newly designed SnTe@GO/GCE is an excellent sensor for nitrite species even in real water sample analysis.

7 illus, 3 tables, 38 ref

042030   JOSEPHINE G A S, SIVASAMY A (CSIR-Central Leather Research Institute, Chennai - 600 020, Tamil Nadu, Email: arumugamsivasamy@yahoo.co.in) : Degradation of Orange G and Malachite green dyes under visible light irradiation: Double layered core-shell nanoparticle as an efficient photocatalyst. Indian J Chem Sec A 2020, 59A(09), 1259-64.

Core-shell nanomaterials have emerged as a frontier area of focus in materials chemistry and catalysis. Here, we have explored the photocatalyst potential of a double layered core-shell material comprising a rare earth material as core and silica, zinc oxide as the subsequent shell materials. The prepared core-shell has average particle size of 40-60 nm, and the material has been characterized by FTIR, XRD, UV-DRS and FESEM techniques. The band gap energy of prepared material is 2.82 eV. The photocatalytic activity has been tested against Orange-G and Malachite green dye under visible light irradiation. A comparison for degradation of azo and non-azo dye has been elucidated. Preliminary studies with varying pH, catalyst dosage and initial dye concentration have been done to determine the optimum parameters for photocatalytic activity. The kinetic studies follow pseudo-first-order pathway. The prepared core-shell nanomaterial is found efficient for degradation of non-azo dye compared to azo dye. Both the materials show better activity than pristine ZnO. The photocatalyst is found to be environmentally benign with reusability even up to the third cycle of reuse.

6 illus, 28 ref

042029   RAO K T, RAO L V, KANDEPI V V K M (Chemistry Dep, Gitam Institute of Science, Visakhapatnam - 530 045, Email: tirumalwithu@gmail.com) : A novel validated eco-friendly RP-UHPLC method for assay and related substances in Meropenem. Indian J Chem Sec A 2020, 59A(08), 1148-57.

A simple, rapid, sensitive, specific, eco-friendly and stability-indicating linear gradient liquid chromatographic method (RP-UHPLC) for simultaneous estimation of assay and its related compounds in Meropenem API samples is developed and validated. Chromatographic separation was achieved on Zorbax Eclipse plus C18, (100 x 4.6) mm, 3.5 µm RRLC short column and 10 mM potassium dihydrogen orthophosphate is used as buffer, buffer solution used as eluent A and buffer and acetonitrile combination 30: 70 v/v ratio used as eluent B and Agilent RRLC (UHPLC) system is used for analysis. The mobile phase flow rate was 1.0 ml/min, and the eluted compounds have been monitored at 220 nm for related substance method and 290 nm for assay method. Excellent resolution is obtained between Meropenem and its related compounds which were eluted within 10 min. The correlation co-efficient(r) is > 0.995 for both the methods from linearity data and percentage of recovery is 98.0 to 102.0 and 80.0 to 120.0 % for assay method and for related substance method, respectively. Sensitivity of the method is found to be less than 0.316 µg/ml. Peak homogeneity data for Meropenem in the chromatograms from the stressed samples are obtained by using photodiode array detector demonstrated the specificity of the method for analysis of Meropenem in presence of the degradation compounds. The performance of the method is validated according to the present ICH guidelines for specificity, limit of detection, limit of quantification, linearity, accuracy, precision, and robustness.

9 illus, 10 tables, 27 ref

042028   MOODLEY K G, ARUMUGAM V, OGUNDELE O P, XU H, REDHI G G, GAO Y (Chemistry Dep, Durban Univ of Technology, Durban 4001, South Africa, Email: ygao@hainanu.edu.cn) : Thermophysical and thermodynamic properties of binary liquid systems of [BMIM][MeSO₄] ionic liquid with carboxylic acids. Indian J Chem Sec A 2020, 59A(08), 1136-47.

Thermophysical properties, namely, density (ρ) and speed of sound (u) of binary mixtures of 1-butyl-3-methylimidazolium methyl sulphate [BMIM][MeSO₄] ionic liquid (IL), with acetic acid or propionic acid have been measured in the mole fraction range from 0.1 to 1.0 at temperature ranging from 293.15 to 313.15 K at a 5 K interval, under atmospheric pressure of 101 kPa. From these measured values, the derived thermodynamic parameters, such as, isentropic compressibility (κ_s), deviation in isentropic compressibility (Δκ_s), excess molar volume (V) and intermolecular free length (L_f) have been calculated. It is observed that V and Δκ_s decrease with increasing the temperature. Furthermore, these values are negative in the whole range of binary compositions. The measured data and variations in derived thermodynamic values suggest that significant interactions occur when the IL forms a binary mixture with carboxylic acids. These derived thermodynamic parameters (V, L_f and Δκ_s) are correlated byusing the Redlich-Kister polynomial equation to generate binary factors and standard errors.

5 illus, 3 tables, 62 ref

042026   KUMAR M M, HIMAJA D, SEN S (Srikrupa Institute of Pharmaceutical Sciences, Siddipet, Telangana - 502 277, Email: sandipsen2010@gmail.com) : In vitro incompatibility study of Valsartan and Hydrochlorothiazide by spectroscopic and RP-HPLC Method. Indian J Chem Sec A 2020, 59A(08), 1120-7.

The present investigation is based on an in vitro incompatibility study between valsartan and hydrochlorothiazide by spectroscopic and reverse-phase high-pressure liquid chromatography (RP-HPLC) methods. The method has been developed and validated by ultraviolet (UV) spectroscopic method using methanol and water (1:4) as the solvent. The RP-HPLC study has been carried out using acetonitrile, methanol and 50 Mm phosphate buffer (20:50:30 %) adjusted to pH 3 with orthophosphoric acid. The methods show linearity at the concentration range of 1-5 μg/ml with correlation coefficient 0.9994 for valsartan and 0.9978 for hydrochlorothiazide in the concentration range of 1-5 μg/ml. Both the methods have shown a percentage relative standard deviation values less than 2. The in vitro incompatibility study has been carried out by UV-spectroscopic and RP-HPLC methods. The results of the study show that there is a change in the concentration level of both drugs in combination. The structure of the interacting compound has been determined by spectral analysis using IR, ¹H NMR and LC-MS study. The spectral analysis confirms the formation of the new complex between valsartan and hydrochlorothiazide. The results obtained from the LC-MS study also correlate the reason behind an increase in the concentration of valsartan and decreases the concentration of hydrochlorothiazide during recovery study by spectroscopic and RP-HPLC method.

10 illus, 9 tables, 17 ref

042024   BEHURA R, BEHERA S, PALAI B B, MISHRA S, MISHRA M, BEHERA S, NATH G, JALI B R (Chemistry Dep, Veer Surendra Sai Univ of Technology, Burla, Odisha, Email: bigyan.Jali7@gmail.com) : Ultrasonic velocity and allied acoustical parameters of 2, 4-dinitrophenyl hydrazine based Schiff base in DMSO. Indian J Chem Sec A 2020, 59A(08), 1108-12.

Novel 2, 4-dinitrophenyl hydrazine based Schiff bases (L1-L3) has been successfully synthesized and characterized. The ultrasonic velocity (C) and density (ρ) has been measured for the synthesized Schiff bases with DMSO (Dimethyl sulfoxide) solvents at 300 K. Using these experimental data ultrasonic Velocity, adiabatic compressibility, intermolecular free length and specific acoustic impedance have been evaluated. From the experimental data, it has been found that L1 ascribed higher ultrasonic velocity as compared to other molecular probes L2 and L3. The strength and nature of interaction between the molecular probes and DMSO solvents has been discussed. Scanning electron microscope studies of molecular probes are performed to discuss the microstructure and surface functionalities.

2 illus, 1 table, 23 ref

042023   KUMAR S L, INDIRAJITH P, TETALA K K R (Vellore Institute of Technology, Vellore, Tamilnadu - 632 014, Email: kishore.tetala@gmail.com) : Onion based zinc oxide nanoparticles ability as electrochemical sensor. Indian J Chem Sec A 2020, 59A(08), 1100-7.

This work describes the preparation of zinc oxide nanoparticles (ZnO NP) from onion extract through a combination of microwave irradiation and muffle furnace in less than 2 h. Characterization with UV-visible, FTIR, and XRD has confirmed successful formation of nanoparticles. TEM analysis displays the nanoparticles to be spherical shaped with an average size of 6.4 nm. The developed ZnO NP film displays good sensing capability of dopamine and had an oxidation potential of + 0.3 V. Under optimized conditions (pH and scan rate), the ZnO NP-GCE is stable even at 500 rpm, showed good linearity in sensing dopamine within the tested range of 3.9-250 µM, has a limit of detection of 3.53 µM and stable electrocatalytic activity even after 30 cycles. The newly developed electrode can distinguish dopamine in a satisfactory way in presence of ascorbic acid and glucose and with 94.9 % of detection in human urine. This study also highlighted the potential of IO Rodeostat (an open source electrochemical workstation) as a feasible option in low resource laboratories to perform sensing studies.

6 illus, 1 table, 44 ref

042022   SUDHEERA M, RAVINDER G, RAVI G, VENKATASWAMY P, VAISHNAVI K, CHITTIBABU N, VITHAL M (Chemistry Dep, Osmania Univ, Hyderabad - 500 007, Email: mugavithal@gmail.com) : Synthesis, characterization and photocatalytic dye degradation studies of novel defect pyrochlore, KHf_0.5Te_1.5O₆. Indian J Chem Sec A 2020, 59A(08), 1092-9.

In this study, KHf_0.5Te_1.5O₆ (KHTO) semiconductor has been synthesized by the solid-state method. The synthesized material is characterized using X-ray diffraction, Fourier transform infrared spectroscopy, UV-visible diffuse reflectance spectroscopy, field emission-scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy and N₂ adsorption/desorption measurements. The material is found to be crystallized in a cubic lattice with the space group Fd3m . The bandgap energy of the KHTO is 2.6 eV. The photocatalytic activity of KHTO has been investigated by measuring the degradation of methylene blue (MB) and methyl violet (MV) dyes under the visible light irradiation. The mechanistic dye degradation pathway of MB has been studied. The radical quenching experiments reveal that the short-lived species O₂^●-, OH^●, and h⁺ actively participate in the degradation of MB and MV dyes. An additional terephthalic acid experiment has been carried out to establish the participation of OH^● radicals in the dye degradation. The stability and reusability of the KHTO catalyst are also studied.

11 illus, 1 table, 29 ref

042021   SAWANT V J, LAVATE D A, KHOMANE A S (Chemistry Dep, Shivaji Univ, Kolhapur, Maharashtra - 416 004, Email: sawantvikas8877@gmail.com) : Cadmium sulfide decorated with carbon nanoparticles from peanut shells: An efficient photocatalyst. Indian J Chem Sec A 2020, 59A(08), 1084-91.

Carbon decorated cadmium sulfide nanoparticles have been synthesized by chemical precipitation method in aqueous medium using dichloroacetic acid as a complexing agent to study their optical and photocatalytic properties. Carbon nanoparticles have been prepared from waste peanut shells by simple pyrolysis method. The as-prepared materials have been characterized by XRD analysis, UV-visible diffuse reflectance spectroscopy, spectrofluorometer, FTIR and BET analysis. SEM and TEM images indicate nano crystallites with spherical agglomeration of average 40 nm size. Band gap energy for pure CdS is observed in the order of 2.4 eV. As prepared carbon decorated CdS nanoparticles with increased surface area efficiently catalyzed the photodegradation of Rhodamine B dye solution under sunlight irradiation than pure CdS.

11 illus, 1 table, 29 ref

042020   MANDAL S P, MONDAL B, SAHA R, KUNDU M, ROY U K (Chemistry Dep, Kazi Nazrul Univ, Asansol, West Bengal - 713 340, Email: uroccu@gmail.com) : Reactivity of electrochemically synthesised zinc nanofiber in facile reduction of nitro and azide compounds. Indian J Chem Sec A 2020, 59A(08), 1076-83.

Electrochemistry is used in generation of metallic nano zinc wire from aqueous zinc chloride. For this electrochemical process we have designed a unit galvanic cell. During the electrochemical process both aliphatic and aromatic nitro and azide compounds undergo facile reduction to the corresponding amines. ZnCl₂ is used as stoichiometric reagent and causes electrochemical deposition of zinc in cathode. During the process wire shaped nano zinc architecture has been formed in cathode which is supposed to be the active reagent for reduction. The cathode deposited material has been characterised by powder XRD, XPS, FESEM, HRTEM, EDX, SQUID etc. The corresponding amines are prepared in good yields. Both zinc salts and aqueous solution can be recycled.

5 illus, 5 tables, 12 ref

042019   TANDEKAR S, SARAVANAN D, JUGADE R (Chemistry Dep, R.T.M. Nagpur Univ, Nagpur - 440 033, Email: ravinj2001@yahoo.co.in) : Zirconia-chitosan beads as highly efficient adsorbent for defluoridation of water. Indian J Chem Sec A 2020, 59A(08), 1067-75.

Zirconia modified chitosan beads (Zr-CTS) have been synthesized as adsorbent for fluoride ions from water bodies. The beads have been characterized using FTIR, SEM, EDX, TG-DTA and BET surface area analysis. Batch adsorption parameters are performed for defluoridation of water using the prepared composite. The pH point of zero charge was found to be 5.7. Maximum efficiency of the adsorbent is observed at pH 4.0, with adsorbent dose of 40 mg per 25 mL of 25 ppm fluoride solution and adsorption period of 45 min. Under these conditions, Zr-CTS is found to have an adsorption capacity of 52.63 mg g^-1 in accordance with Freundlich adsorption isotherm. Thermodynamics parameters reveal that the process of adsorption was spontaneous, exothermic and leading to increase in entropy. The process follows pseudo-second-order kinetics model. The used material is regenerated using 5% NaCl solution and could be reused in multiple cycles adding greener dimension.

8 illus, 3 tables, 12 ref

042016   MOSTERT F J, RWEXWANA A, TSEKI P F (Chemical and Physical Sciences Dep, Walter Sisulu Univ, Mthatha, South Africa, Email: ptseki@wsu.ac.za) : Remarks on the modelling of molecular binding forces in the Glue-DNT interaction. Indian J Chem Sec A 2020, 59A(07), 948-51.

The interactions between cyanoacrylate type of glue and model compounds for dinitrotoluene (DNT) and trinitrotoluene (TNT) are investigated using mainly spectroscopic techniques. Electrostatic fields emanating from dispersion and dipole interactions are thought to dominate the energy of interaction without any evidence for hydrogen bonding between the glue and any of the substrates. Vibronic spectral data strongly suggests polarization of the vibrational manifolds of the substrates. Careful analysis of nuclear magnetic resonance (nmr) spectral data reveals a good correlation between the nmr chemical shifts and the measured infrared shifts in the glue matrix. This profound observation may have implications for theoretical calculations of nmr chemical shifts.

2 illus, 1 table, 18 ref

042015   MIR J M, MIR M A, MAJID S A (Chemistry Dep, Islamic Univ of Science and Technology, Awantipora, Jammu & Kashmir - 192122, Email: mirjanmohammad@gmail.com) : Molecular electron density and nitrate-phosphate sorption efficiency of zeolite-A: Physico-chemical and DFT analyses. Indian J Chem Sec A 2020, 59A(07), 939-47.

Design of nitrate and phosphate carrying molecular scaffolds is significant in various sectors of applied interest. Motivated towards this interesting field, herein a combined experimental-DFT study of zeolite-A is reported. The sorption efficiency of this complex framework towards nitrate and phosphate ion has been analyzed. The implications of surface modification, change in pH and temperature upon the property of ion adsorption/absorption have been discussed. An increasing trend in sorption is observed up to pH~7 and up to temperature ~ 40 °C. In addition to experimental measures theoretical calculations have also been added to discuss the optimal frame work of the zeolite using Stuttgart-Dresden basis set and WB97XD as functional. Molecular simulations involving spectroscopic and electrostatic potential determination have been computed after optimization. A combined experimental and theoretical thermodynamic study has also been the active part of the study. From the study it may be established that the experimental results are in good agreement with the DFT based speculations.

11 illus, 2 tables, 26 ref

042014   SARAVANAN C, CHITUMALLA R K, YUVAKUMAR R, SHANMUGAVELAN P, MAREESWARAN P M, JANG J (Industrial Chemistry Dep, Alagappa Univ, Karaikudi, Tamilnadu, Email: mareeswaran@alagappauniversity.ac.in) : Experimental and theoretical investigations on the host-guest interaction of diphenylamine with p-sulfonatocalix[4]arene. Indian J Chem Sec A 2020, 59A(07), 929-38.

The intermolecular interaction between diphenylamine (DPA) and p-sulfonatocalix[4]arene (p-SC4) is studied by experimental and computational techniques. The 1:1 stoichiometry of the inclusion complex is deduced from fluorescence titration using Job’s method. The tendency of binding of DPA with p-SC4 is analyzed from emission, excited state lifetime and cyclic voltammetry techniques. The binding constant values acquired from all the titrations are around 10³–10⁴ L/mol, reveals the effective binding. The structural interactions and mode of binding of the supramolecular complex are explained by ¹H NMR and ROESY spectral studies. The molecular association of DPA with p-SC4 is confirmed by quantum chemical simulations. The higher complexation energy (-76.94 kJ/mol) declares the existence of strong binding between DPA and p-SC4.

10 illus, 5 tables, 59 ref

042013   CELIN T S, RAJ G A G (Chemistry & Research Centre Dep, Scott Christian Coll (Autonomous), Nagercoil, Tamilnadu, Email: allengraj@gmail.com) : Luminescence quenching of tris(4,4ʹ-dimethyl-2,2ʹ-bipyridyl)ruthenium(II) complex with quinones in aprotic polar medium. Indian J Chem Sec A 2020, 59A(07), 923-8.

The photoinduced electron transfer interaction between a luminescent metal-ligand probe, [Ru(dmbpy)₃]²⁺ and quinones have been investigated by absorption and fluorescence spectroscopy. The reactions of quinones with the excited state ruthenium(II) complex in DMF have been studied by luminescence quenching technique and the bimolecular quenching rate constant k_q values are found close to the diffusion controlled rate. The complex has an absorption maximum of 458 nm. It shows a photoluminescence at 608 nm. The lifetime of the complex in DMF is 164 ns. The ground state absorption measurements are used to confirm the nature of quenching. Transient absorption spectral measurements are performed and the oxidative nature of quenching is confirmed. The detection of semiquinone anion radical using time resolved transient absorption spectroscopy and the linear variation of log k_q vs reduction potential of the quinones confirms the electron transfer nature of the reaction.

11 illus, 2 tables, 19 ref

042012   ZHANG Y, LI F, ZUO J, NI Y, QIU P (Chemistry Dep, Nanchang Univ, Jiangxi, 33031 China, Email: pingqiu@ncu.edu.cn) : Application of adsorptive stripping differential pulse voltammetry with chemometrics in the determination of ascorbic acid, rutin and quercetin in the food and health products. Indian J Chem Sec A 2020, 59A(07), 914-22.

The simultaneous determination of ascorbic acid, rutin and quercetin in the food and health products on the glassy carbon electrode have been investigated by adsorptive stripping differential pulse voltammetry (AdSDPV) with the aid of chemometrics. In the pH 5.2 KH₂PO₄ – Na₂HPO₄ buffer solution, both rutin and quercetin has shown a pair of sensitive reversible oxidation-reduction peak, while ascorbic acid only has shown an irreversible oxidation peak on the glassy carbon electrode. In the range of 0.35-0.50 V, the vlotammograms of three components has shown serious overlap with peak potential of ascorbic acid, rutin and quercetin. So, it is extremely difficult to realize direct measurement for the content of single component. Chemometrics methods have been introduced to determine the admixture of the three components. In this way, we have avoided the troublesome procedures of separation and purification, and assay the artificial compound of the three components all at once. We have estimated the three components in the food and the health products with satisfactory results.

2 illus, 4 tables, 44 ref

042011   LINGESWARI U D, VIMALA T (Chemistry Dep, Seethalakshmi Ramaswami Coll (Affiliated to Bharathidasan Univ), Tiruchirappalli - 620 002, Tamil Nadu, Email: vimalsrc@gmail.com) : Kinetics, isotherms and thermodynamic modelling of reactive blue 52 and reactive orange 107 dyes from aqueous solution using PANI-CoCl₂ as adsorbent. Indian J Chem Sec A 2020, 59A(07), 904-13.

In this work decolourisation of organic dyes such as Reactive Blue 52 and Reactive Orange 107 from aqueous solution by PANI-CoCl₂ composite have been studied. Polyaniline (PANI) is a viable conducting polymer because of its unique proton dopability, excellent redox recyclability, chemical stability, variable electrical conductivity, low cost and ease of synthesis. The morphology of PANI-CoCl₂ composite have been characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. It is also shown that many factors affected the adsorption rate, such as adsorbent mass, contact time, variation of pH, agitation speed, dye concentration and temperature. The capacity of the adsorbent is tested using recyclability process. Adsorption of Reactive Blue 52 and Reactive Orange 107 by PANI-CoCl₂ follows pseudo-second-order kinetics and the best-fit isotherm is the Langmuir model which is confirmed by using correlation coefficients in ANOVA technique. The thermodynamic parameters like changes in free energy, enthalpy and entropy have been also calculated.

19 illus, 5 tables, 35 ref

042010   ZHANG J,PANG Z, DONG C (Shanxi Univ, Taiyuan 030006, PR China, Email: dc104@sxu.edu.cn) : Synthesis and spectral studies of coumarin derivatives as fluorescent probes towards Fe³⁺ and Cu²⁺. Indian J Chem Sec A 2020, 59A(07), 895-903.

Three novel coumarin derivatives have been designed and facilely synthesized, namely 6-[bis-(2-acetoxyethyl)aminomethyl]-4-methyl coumarin (BAMC), 4-(trans-4-methylformate-styryl)-6-[bis-(2-acetoxyethyl) aminomethyl]-coumarin (TSAC) and Trans-4-[2-(benzimidazole-2-substituted)vinyl]-6-methyl coumarin (TBVC). The synthesis route of the coumarin derivatives via various reactions including Pechmann, Wittig and substitution, three strategies are applied in the construction of the coumarin-based fluorescent probes, in view of the impact of the electronic push-pull effect, extended electronic conjugated system, and the strong fluorescence emission group, respectively. The compounds BAMC and TSAC are proved to be selective fluorescent probes to Fe³⁺ and Cu²⁺ based on the intramolecular charge transfer mechanism. TBVC exhibits enhanced fluorescent emission in tetrahydrofuran offers the potential for the high-performance fluorescent probe. The relationship between the structure and the fluorescence mechanism of coumarin probes is explored.

3 illus, 4 tables, 39 ref

042009   ZHANG Y, WEI X, WANG Z (Northwest Normal Univ, Lanzhou, 730070, P. R. China, Email: zhwang@nwnu.edu.cn) : A sensitive and selective fluorescence sensing of bisphenol A based on magnetic Fe₃O₄@SiOsub>2@QDs@MIPs nanoparticles. Indian J Chem Sec A 2020, 59A(07), 887-94.

A flexible magnetic and fluorescent sensing for the recognition and detection of bisphenol A (BPA) based on a hybrid magnetic Fe₃O₄@silica nanoparticle@Mn:ZnS quantum dots@molecularly imprinted polymers nanoparticles (Fe₃O₄@SiO₂@QDs@MIPs NPs) has been designed. Because of the high selectivity of MIPs, the strong fluorescence property of Mn:ZnS QDs, good magnetism of Fe₃O₄ and good water solubility of SiO_2, the Fe₃O₄@SiO₂@QDs@MIPs NPs can effectively detect BPA effectively in human urine. In the presence of BPA, a new compound is produced via the amino group of Fe₃O₄@SiO₂@QDs@MIPs NPs and the hydroxyl group of BPA, the energy of the QDs is transferred to the compound, which led to fluorescence quenching. The relative fluorescence intensity has decreased linearly with the increasing of BPA concentration in the range 50 to 700 ng/mL and the detection limit is found to be 1.6 ng/mL. In addition, the sensor has shown a strong selectivity with an imprinting factor of 8.7 and distinguished selectivity is also exhibited to BPA over other possibly competing molecules. On the basis of the merits of the Fe₃O₄@SiO₂@QDs@MIPs NPs, the sensor can be applied to detect BPA in human urine sample successfully.

3 illus, 1 table, 54 ref

042008   HAN D, LI J (Changchun Univ of Science and Technology, Changchun 130022, P. R. China, Email: ljmljmcust@163.com) : The insights from theoretical calculation on the photophysical properties of a series of phosphorescent iridium(III) complexes. Indian J Chem Sec A 2020, 59A(06), 816-20.

The electronic structure and photophysical properties of three Ir(III) complexes with the substituted 5,5′-di(trifluoromethyl)-3,3′-bipyrazole(bipz) ligand have been theoretically investigated by using density functional theory and time-dependent density functional theory method. The calculated results show that the energy gaps between of LUMO and HOMO (ΔE_L→H) of complexes 1, 2 and 3 are gradually decreased, that is, 3.54 eV, 3.07 eV and 2.95 eV for 1, 2 and 3, respectively. The lowest energy absorption wavelength of 1, 2 and 3 are located at 443 nm, 532 nm and 564 nm, respectively. The calculated 443 nm absorption for 1 is in good agreement with the experimental value. The lowest energy emissions of complexes 1, 2 and 3 are localized at 545 nm, 679 nm and 731 nm, respectively, simulated in CH₂Cl₂ medium at TPSSH level. The conclusion can be drawn that the different substituent groups in the bipz ligand results in the important effect on the electronic structure and photophysical properties. The research work can provide valuable information for the design of new organic light-emitting diodes materials.

3 illus, 3 tables, 32 ref

042007   PATEL P, SHARMA S (Chemistry Dep, Hemchandracharya North Gujarat Univ, Patan, Gujarat, Email: sangitamem2000@gmail.com) : Thermophysical, acoustical, spectral and DFT study of intermolecular interactions of terpinolene with cresols. Indian J Chem Sec A 2020, 59A(06), 797-815.

Densities and speed of sound have been measured experimentally for binary mixtures of terpinolene with cresols (o-cresol, m-cresol, p-cresol) at three different temperatures 303.15, 308.15 and 313.15 K at atmospheric pressure. From primary physical properties, some secondary properties like molar volume (V_m), excess molar volume V, partial molar volume (V m,i o ) excess partial molar volume (V m,i o,E ), apparent molar volume (V_m,φ,i), deviation in speed of sound (u), isentropic compressibility ($\mathrm{\mu }$), deviation in isentropic compressibility (K_s), acoustical impedance (z), deviation in acoustical impedances (z), intermolecular free length (L_f), partial molar isentropic compression (K s,m,i o,), excess partial molar isentropic compression (K s,m,i o,E) and apparent molar isentropic compression (K_s,m,φ,i) have been calculated. Infinite dilution apparent molar volume (V,φ,1), infinite dilution apparent molar isentropic compression(K_s,m,φ,1), empirical parameters S_v, B_v and S_k, B_k of the Redlich-Rosenberg-Mayer equation with the limiting apparent molar expansibility (E_φo) have been also calculated along with some theoretical speed of sound calculating relations such as Nomoto relation (u_nmt), Ideal mixture relation (u_imr, Junji relation (u_junji) and Free length theory relation (u_flt) with their standard deviation (σ). All the calculated values of excess/deviation properties have been fitted with the fourth order Redlich-Kister polynomial equation and their standard deviation (σ) values are also calculated. FTIR spectral analysis of binary mixtures at 4:1, 1:1 and 1:4 composition ratios have been carried out at 298.15 K. Computational calculations such as optimization of pure and binary mixtures in gas phase, bond length, Mulliken charges, theoretical vibrational frequencies and NBO calculations on basis of the DFT (Density Functional Theory) have been also carried out. The results are discussed in term of presence of intermolecular interactions, types, strength and behavior with change of temperatures and cresol components in binary mixtures.

11 illus, 9 tables, 37 ref

042006   RAHMAN K M, BISWAS B, NEGER T, SHARMINA N, RAHMAN L (Institute of Glass and Ceramic Research and Testing (IGCRT), Dhaka-1205, Bangladesh, Email: lutforju33@yahoo.com) : Method validation on iron determination by spectrophotometric method in aqueous medium. Indian J Chem Sec A 2020, 59A(06), 790-6.

This paper deals with the validation of a method for the determination of iron in spectrophotometric method in aqueous medium. The method is based on complex formation of iron with thioglycolic acid in alkaline medium in presence of a masking agent to produce a red purple chelate that has an absorption maximum at 535 nm wavelength. Beer-Lambert law is obeyed and linear calibration curves are obtained for the concentration range of iron from 0.1 mg/L to 30 mg/L. The reaction is found to be spontaneous in alkaline medium. The limit of detection and limit of quantification for the developed method are 0.0108 and 0.0345, respectively. Effect of different parameters like molar ratio of iron to different reagents and interferences, effect of time and effect of temperature of this method of determination have been studied. It is found that this method is moderately sensitive and has been successfully applied for the determination of iron(III) in different fields like ceramic materials, clay, sand, glass, stone, soil, water, and any inorganic iron containing compound or alloys. A comparison report is made for Chevron gas field waste material and Certified Reference Material of iron, which is done by atomic absorption and UV-visible spectroscopy techniques and found to be comparable.

5 illus, 8 tables, 25 ref

042004   SUNNY A, PRABU N M (M S Ramaiah Univ of Applied Sciences, MSR Nagar, Bangalore - 560 054, Email: manikanda.cy.mp@msruas.ac.in) : Enhancement of photocatalytic activity of BiVO₄ by barium doping. Indian J Chem Sec A 2020, 59A(06), 775-82.

BiVO₄ has been successfully synthesized by solid state method and doped by barium in the sites of bismuth in 3 %, 6 %, 9 % and 15 % to form Bi_1-xBa_xVO₄ (x = 0.03, 0.06, 0.09 & 0.15). The products have been characterized using powder X-ray diffraction, diffuse reflectance spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and photoluminescence spectroscopy. The band gap of undoped BiVO₄ is calculated to be 2.19 eV and the barium doped BiVO₄ compounds exhibit band gaps which are closer to the band gap of undoped compound. The photocatalytic activities of undoped and doped catalysts for the degradation of methylene blue have been studied using UV-visible spectroscopy and found to be depended largely on the barium content and the particle size of the compounds.

10 illus, 2 tables, 40 ref

042003   BAKRE P V, TILVE S G (Goa Univ, Goa - 403 206, Email: stilve@unigoa.ac.in) : Photocatalytic activity of mixed-phase of TiO₂ synthesized by non-aqueous methodology. Indian J Chem Sec A 2020, 59A(06), 768-74.

A mix-phase (anatase-rutile) nanocrystalline titania particles were successfully synthesized in a non-aqueous solvent medium using a novel approach of controlled hydrolysis of titanium isopropoxide. The hydrolysis was carried out by the controlled release of water molecules from simple Schiff base formation reaction of anisaldehyde employing aniline as an amine component in isopropanol solvent medium. The excess aniline used, and the imine formed acts as directing agents. The photocatalytic activities of the catalysts prepared were compared with Degussa P25 for methylene blue degradation in direct sunlight. The photocatalytic activity was found to increase with decreasing availability of water molecules formed during the Schiff base formation (imination) reaction. Also, it was found to affect the phase and shape selection. TEM images show sphere-like to hexagonal to a rod-shaped formation of particulates.

6 illus, 2 tables, 46 ref

042002   NANDI D, KARMAKAR P, DEY A, SAIN R S, GHOSH A K (Chemistry Dep, The Univ of Burdwan, Purba Bardhaman - 713 104, West Bengal, Email: alakghosh2002@yahoo.co.in) : Thermodynamic and kinetic studies on novel Platinum(II) Complex containing bidentate N,N-donor ligands in ethanol-water medium. Indian J Chem Sec A 2020, 59A(06), 760-7.

Kinetic and mechanistic investigations have been made on the displacement of the two aqua molecules from the complex 1 i.e., [Pt(2,2′-bipyridine)(H₂O)₂]²⁺ represented as {Pt(bpy)} (bpy = 2,2′-bipyridine) at pH 4.0. All the substitution reactions have been monitored at 264, 284 & 317 nm, where the spectral difference between the reactant and product is maximum. Two consecutive reaction steps have been observed for the substitution of aqua molecules with some bidentate N,N-donor ligands namely, dimethylglyoxime (L₁H), 1, 2-cyclohexanedionedioxime (L₂H) and α-furildioxime (L₃H) in ethanol-water medium using variable-temperature and stopped-flow spectrophotometry. Among the two steps, the former is ligand dependent and the later is ligand independent, where chelation is observed. All rate and activation parameters are consistent with associative substitution mechanisms. The thermodynamic parameters have been also calculated, which gives a negative DG⁰ value at all temperatures studied, supporting the spontaneous formation of an outer sphere association complex. The products of the reaction have been characterized with the help of IR and ESI-MS spectroscopic analysis.

6 illus, 4 tables, 24 ref

042000   PRATHYUSHA K R, SREENIVASAN K P (Chemistry Dep, M.E.S Kalladi Coll, Palakkad - 678 583, Kerala, Email: sreenichem@gmail.com) : Synthesis of Na⁺ /Ca²⁺ ions modified TiO₂ xerogels through co precipitation method. Indian J Chem Sec A 2020, 59A(06), 747-51.

We report a facile method for the synthesis of Na⁺/Ca²⁺ ions modified TiO₂ xerogels by coprecipitation followed by calcination process. The resultant materials are well characterized by powder X-ray diffraction, Raman spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy and high resolution transmission electron microscopy. Presence of sodium and calcium ions can influence the crystallinity of rutile TiO₂. The photocatalytic performances of bare rutile TiO₂ along with modified materials such as Na-TiO₂, Ca-TiO₂, Na-Ca-TiO₂ materials are evaluated by calculating the amount of hydrogen evolved during the photocatalytic decomposition of water under light irradiation.This study will be effective informulating the effect of alkali/alkaline earth metal ions on the photocatalytic activity of rutile TiO₂.

5 illus, 29 ref

041999   ROKNUZZAMAN, KHAN M H, ABEDIN S M T, KABIR S E (Chemistry Dep, Jahangirnagar Univ, Dhaka 1342, Bangladesh, Email: skabir_ju@yahoo.com) : Molybdenum compounds bearing pymS (pyrimidine-2-thiolato) and tertiary phosphine ligands. Indian J Chem Sec A 2020, 59A(06), 741-6.

In this paper we have reported mono- and dinuclear molybdenum compounds containing doubly bridging pymS (pyrimidine-2-thiolato) and P(Fu)₃ {(Fu = (2-furyl)phosphine)} or P(OMe)₃ (trimethyl phosphite). One-pot reaction between [Mo(CO)₃(NCMe)₃] and pymSH (pyrimidine-2-thiol) in the presence of P(Fu)₃ in THF at 50 °C gives the previously reported eight coordinate compound [Mo(к²-pymS)₄] (1) in 17 % yield and two new compounds [Mo(CO)₄(P(Fu)₃)₂] (2) and [Mo₂(CO)₄(μ-к²-pymS)₂(P(Fu)₃)₂] (3) in 51 and 15 % yields, respectively. A similar reaction involving P(OMe)₃ furnishes two mononuclear compounds [Mo(CO)₂(κ²-pyS)₂(P(OMe)₃)] (4) and [Mo(CO)₄(P(OMe)₃)₂] (5) in 20 and 35 % yields, respectively. Compounds 2 and 4 are characterized by single-crystal X-ray diffraction analysis in addition to IR, ¹H NMR and ³¹P{¹H} NMR spectroscopic methods.

2 illus, 2 tables, 23 ref

041998   WANG G, ZHANG H, WANG M, WANG Y, XIA C, FU S, XU F (Qiqihar Medical Univ, Qiqihar 161006, PR China, Email: zhanghg@qmu.edu.cn) : Morphology-dependent photocatalytic activity of TiO₂ crystals. Indian J Chem Sec A 2020, 59A(05), 646-51.

TiO₂ crystals with different morphologies have been successfully synthesized by simple hydrothermal method. All samples are characterized carefully by XRD, SEM, TEM, and BET techniques and the morphological effect on the photocatalytic activity of the obtained TiO₂ crystals has been evaluated by degrading the pollutant molecules. The experimental results show that the TiO₂ samples with different morphologies exhibited different activities to pollutant degradation. The core-shell spheres have exhibited the best photocatalytic activity, with the almost complete degradation of methyl orange (MO) and rhodamine B within 15 min under UV-light irradiation. After 20 min UV-light irradiation, the degradation efficiency of the MO solution is about 68.9 %. It can be concluded that a morphological effect is responsible for the photocatalytic performance. The crystals with large BET surface area, the small crystallite size shows the better the photocatalytic performance.

7 illus, 1 table, 25 ref

041997   SINGH U, LOONKAR S, MICHELI L, KUMBHAT S (Chemistry Dep, J.N.V. Univ, Jodhpur, Rajasthan, Email: sunitakumbhat@gmail.com) : Label free biosensor for screening estrogenic activity. Indian J Chem Sec A 2020, 59A(05), 640-5.

Estrogens and estrogen mimics prevalent in aquatic environment are of great environmental concern because of their endocrine disrupting and carcinogenic activities. Looking to the wide variety of natural as well as structurally different synthetic estrogen mimics, a reliable in-vitro assay is required for screening the estrogenic activity of endocrine disrupting compounds (EDCs). Surface plasmon resonance (SPR) is one of the most promising analytical tools to monitor the high-performance biomolecular interactions in a label free, real time format. Present paper demonstrates a facile SPR based affinity bioassay employing estrogen receptor-α, human (hERα) functionalized self assembled monolayer covalently bound onto the gold sensor chip as recognition species. A successful interaction of potential estrogen mimics with estrogen receptor is evidenced by net rise in SPR angle. The assay has been validated in terms of optimum experimental conditions and specificity with estrogen as a positive control showing maximum estrogenic activity. As a proof of concept, proposed affinity assay is tested for screening the estrogenic activity of progesterone, pregnenolone, tamoxifen, and bisphenol-A as representative examples of potential EDCs of different classes.

3 illus, 1 table, 26 ref

041995   XIA Q, ZHANG S P, QU S, ZHU Y Z, MA J, ZHANG Z (Shanghai for Science and Technology Univ, Shanghai 200093, China, Email: zhang_lucy9999@vip.126.com) : Surface decoration of multi-walled carbon nanotubes modified carbon paste electrode with CuO nanoparticles for electrocatalytic oxidation of nitrite. Indian J Chem Sec A 2020, 59A(05), 625-32.

In this paper, CuO nanoparticles have been electrodeposited onto the film of multiwalled carbon nanotubes (MWCNTs) modified carbon paste electrode (MWCPE), which fabricated a sensitive nano-copper oxide coated multi-walled carbon nanotubes modified carbon paste electrode (CuO_nano/MWCPE) to detect nitrite. Scanning electron microscope (SEM) image have indicated that copper oxide nanoparticles desposited on MWCPE are homogeneous. The CuO_nano/MWCPE has been used to detect nitrite by square wave voltammetry and cyclic voltammetry techniques. The sensor has exhibited outstanding performance for the electrocatalysis of nitrite. Electrocatalytic oxidation of nitrite at the surface of CuO_nano/MWCPE has been remarkably improved compared to the unmodified CPE and the MWCPE. Under optimum conditions, the oxidation current is linear with the concentration of nitrite ion in the range of 5 μM – 1000 μM. The detection limit has evaluated to be 1.25 μM (S/N = 3). The sensor has been successfully used to determine nitrite in water samples with excellent recoveries.

7 illus, 2 tables, 46 ref

041994   SANGEETHA D N, POOJA H, BHANDARY S, SHETTY Y, SUBASHCHANDRABOSE R, SELVAKUMAR M (Chemistry Dep, Manipal Institute of Technology, Manipal - 576 104, Email: chemselva78@gmail.com) : Flexible modified plastic strips coated polyaniline/graphene composite for electrochemical biosensors. Indian J Chem Sec A 2020, 59A(05), 616-24.

Polyaniline(PANI)/graphene modified flexible, disposable polyester overhead projector (OHP) strips for non-enzymatic detection of ascorbic acid (AA) and uric acid (UA) is demonstrated in the current work. The deposition of PANI on the 3-aminopropyltrimethoxy silane (APTMS) modified OHP have been optimized through electrochemical impedance spectroscopy. Graphene is coated on another end. The PANI/graphene coating is confirmed through scanning electron microscopy. UA and AA detection have been carried out using the standard electrochemical techniques like cyclic voltammetry and chronoamperometry. The study reveals that the composite of PANI/graphene exhibits good sensing towards the detection of UA and AA. During the detection of UA and AA, PANI/graphene has showed enhanced current density with quick response and a linear concentration range of 10 to300 M for UA and 30 to 80 M for AA. These flexible sensor strips may be of great potential in real-time UA and AA detection.

6 illus, 1 table, 35 ref

041993   KASIMBI D, REDDY K H, DEVANNA N (Chemistry Dep, Sri Krishnadevaraya Univ, Ananthapuramu - 515 003, Email: khussainreddy@yahoo.co.in) : Synthesis, spectral studies and antibacterial activity of iron(III) complexes with hydrazone functionalized ligands: X-Ray structure determination of a novel five coordinate complex containing labile ligands. Indian J Chem Sec A 2020, 59A(05), 608-15.

Iron(III) complexes having general formula FeLCl₂ [where, L = 2-acetylpyridine acetoylhydrazone (APAH), 2-acetylpyridine benzoylhydrazone (APBH), 2-acetylthiophene acetoylhydrazone (ATAH), and 2-acetythiophene benzoylhydrazone (ATBH)] have been synthesized and characterized based on molar conductivity, electronic and IR spectroscopy. The structure of iron(III) complex with APBH ligand is determined using single crystal X-ray crystallography. The complex crystallizes in monoclinic space group P21/n with a = 7.8490(6) Å, b = 15.1018(11) Å, c = 13.2263(10) Å, α = 90°, β=100.183(3)°, γ = 90°, V = 1543.1(2) ų and Z = 4 with central Fe(III) ion coordinated by one tridentate APBH ligand. The iron is involved in 5-coordinate bonding with one organic (hydrazone) unit and two labile chloride ligands. The ligand acts as NNO–tridentate donor system. Iron is coordinated to pyridine ring nitrogen, azomethine nitrogen and benzoyl oxygen atoms and the two chloride ligands bind with metal completing distorted square pyramidal structure. The ligands and iron complexes are screened for their anti-bacterial activities against Pseudomonas aureoginos and Bacillus cereus. Among ligands, acetoyl hydrazones show more activity than the corresponding benzoyl hydrazones. The hydrazones having a methyl/ and pyridine groups show higher antibacterial activity. The iron complexes show higher activity than the metal free ligands.

5 illus, 4 tables, 53 ref

041992   CHAVAN S S, DEVKULE S S (Chemistry Dep, Shivaji Univ, Kolhapur - 416 004, Maharashtra, Email: sanjaycha2@rediffmail.com) : Copper(I) complexes with N-(2-quinolinylmethylene)-1, 5-dimethyl- 2-phenyl-1- pyrazole-3-(2H)-one and phosphine as ligands: Effective catalyst for Sonogashira cross-coupling reaction. Indian J Chem Sec A 2020, 59A(05), 598-607.

A new series of copper(I) complexes of the type [Cu(L)(PPh₃)₂]X (1a-c) and [Cu(L)(dppe)]X (2a-c) have been prepared by the reaction of Cu(MeCN)₄]X (where X = ClO, BF and PF) with N-(2-quinolinylmethylene)-1,5-dimethyl-2-phenyl-1-pyrazole-3-(2H)-one (L) in presence of triphenylphosphine (PPh₃) or 1,2-bis(diphenylphosphino)ethane (dppe) as an ancillary ligand. The UV-visible spectra indicate that, the ancillary phosphine ligands significantly perturb the MLCT state of copper(I) complexes. The thermally stable 1a-c and 2a-c complexes exhibit quasireversible redox behaviour corresponding to Cu(I)/Cu(II) couple. All complexes are tested as catalyst for Sonogashira cross-coupling of phenylacetylene with aryl iodide. The results show that all complexes worked as an effective catalyst at low temperature yielding substituted aryl alkynes as a product. The nature of phosphine ligands and size of counter anions shows marked effect on catalytic properties of all the complexes.

2 illus, 3 tables, 39 ref

041990   RANADE P B, NAVALE D N, ZOTE S W, RAMANA M M V (Chemistry Dep, Vivekanand Education Society’s Coll of Arts, Chembur, Mumbai - 400 071, Email: prasannaranade@yahoo.com) : Synthesis and interaction of thiazolo [2, 3-a] isoquinoline analog with DNA. Indian J Chem Sec A 2020, 59A(04), 569-73.

A reaction between 1-(furan-2-yl)-3,4-dihydroisoquinoline and thioglycolic acid using N,N-Dicyclohexylcarbodiimide at 0−5 °C has given 10b-(furan-2-yl)-5,6-dihydro-2H-thiazolo[2,3-a]isoquinolin3(10bH)-one [FUIQTGA]. The interaction between FUIQTGA and DNA has been studied using UV-visible spectroscopy, fluorescence and circular dichroism techniques. Static quenching mechanism is observed from fluorescence measurements of interaction between FUIQTGA and DNA. Circular dichroism reveals the minor groove binding mode between FUIQTGA and DNA.

3 illus, 1 table, 32 ref

041989   PRAKASH C, BANSAL S (Mehr Chand Mahajan DAV Coll for Women, Chandigarh - 160 036, Email: shafibansal@yahoo.co.in) : Room temperature ionic liquid based extraction and recovery of Rifampicin from water and its mechanistic study. Indian J Chem Sec A 2020, 59A(04), 563-8.

An attempt has been made to develop a fast, efficient and eco-friendly process for extraction of drug; Rifampicin (RF) from its aqueous solutions using room temperature ionic liquids (RTILs). RTILs viz. 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium tetrafluoroborate and 2-Hydroxyethyl-trimethylammonium L-(+)-lactate have been used for removal of RF. Various factors such as hydrophilicity/hydrophobicity of RTILs, concentration of used RTILs and pH of drug solutions, affecting removal of RF from its aqueous solution have been studied to investigate mechanism of extraction process. Partition coefficient of RF between RTILs and aqueous phases as well as its extraction efficiency have also been calculated and analyzed. Results showed that hydrophobicity plays a major role in extraction of RF from its aqueous solutions. The addition of just 2 % of hydrophobic RTIL; [BMIM][PF₆] leads to almost complete precipitation (98.92 %) of RF in just 1 min. Also, it has been observed that extraction efficiency of [BMIM][PF₆] is maximum at pH = 8.

7 illus, 28 ref

041988   CHHETRI N, BHOITE S A, SINGH A K, JAIN B (Chemistry Dep, Govt. V. Y. T. P.G. Autonomous Coll, Durg, Chhattisgarh - 492 010, Email: ajayaksingh_au@yahoo.co.in) : Effect of micelles on hydrolysis of di-2,3-dichloroaniline phosphate. Indian J Chem Sec A 2020, 59A(04), 551-62.

The effect of anionic surfactant, di-octylsodium sulphosuccinate (AOT) and nonionic surfactant, polyoxyethylene sorbitanmonooleate (Tween-80) on the hydrolysis of di-2,3-dichloroaniline phosphate was studied spectrophotometrically at 303 K. The influence of inorganic salts on the reaction rate was studied. The added salts viz. KCl, KNO₃, and K₂SO₄ accelerated the rate of the reaction in the presence of anionic and nonionic micelles. The role of anionic and non-ionic micelle has been explained by the Menger-Portnoy, and Piszkiewicz models. The binding constant (K_s), rate constant (k_ψ) in the micellar phase, co-operativity index (n) and various thermodynamic activation parameters viz. ∆E_a, ∆S^≠ , ∆H^≠ , ∆G^≠ etc. have been evaluated. Possible reaction mechanism has been proposed on the basis of the observed kinetic data.

9 illus, 4 tables, 41 ref

041987   ELMAS G, OKUMUS A, KILIC Z, OZBEDEN P, ACIK L, TUNAL I B C, TURK M, CERCI N A, HOKELEK T (Chemistry Dep, Ankara Univ, Ankara 06100, Turkey, Email: gegemen@ankara.edu.tr) : Phosphorus-nitrogen compounds. Part 48. syntheses of the phosphazenium salts containing 2-pyridyl pendant arm: Structural characterizations, thermal analysis, antimicrobial and cytotoxic activity studies. Indian J Chem Sec A 2020, 59A(04), 533-50.

The phosphazenium salts (protic ionic liquids, PILs/protic molten salts, PMOSs) (6a-6d and 7a) of the free phosphazene bases (4a-4d and 5a) have been prepared by the reactions of the corresponding cyclotriphosphazenes with the bulky gentisic acid. The structures of the PMOS have been evaluated using the elemental analyses, FTIR, ¹H, ¹³C{¹H} and ³¹P{¹H} NMR data. The molecular and crystal structures of 4a and 6c are established by X-ray crystallography. The thermal properties of the PMOS are determined using TG and DTA techniques. On the other hand, the antimicrobial activities of the free phosphazene bases (4a-4d and 5a-5d) and PMOSs (6a-6d and 7a) are screened against the selected bacteria and yeast strains. The antimicrobial activities of the free phosphazene bases and the PMOSs are compared. The interactions of the phosphazenes and their salts with plasmid DNA are elucidated by the agarose gel electrophoresis. The evaluations of the cytotoxic activities of these compounds are also studied against to L929 fibroblast and breast cancer cells (MDA-MB-231).

6 illus, 11 tables, 60 ref

041986   ULUCAM G, YENTURK B (Chemistry Dep, Trakya Univ, Edirne 22030, Turkey, Email: gulergul@trakya.edu.tr) : VO(IV) complexes of N₂O₂ tetradentate ligands with flexible alkyl spacer: Synthesis, characterization and antibacterial activities. Indian J Chem Sec A 2020, 59A(04), 526-32.

Three Schiff base ligands which contain N₂O₂ donors and their oxo-vanadium(IV) complexes have been synthesized. The ligand C₁₄H₁₆N₂O₂ has obtained as a result of the reaction of 1,4-diaminobutane with 2-furan-carboxyaldehyde within the framework of Schiff base condensation method. The same reaction path is followed replacing 1,4-diaminobutane by 1,6- diaminohexane and 1,8-diaminooctane in separate reactions to obtain the two other new ligands. Then, the synthesized ligands are employed to attain the oxo-vanadium(IV) complexes as results of their reactions with VOSO₄.H₂O. The ligands have been characterized by FTIR, ¹³C NMR, ¹H NMR, and LC/ESI-MS. The VO(IV) complexes have been elucidated by FTIR, LC/ESI-MS, energy dispersive X-ray spectroscopy, thermogravimetric methods, and the conductivity and magnetic susceptibility measurements. The antibacterial activities of the ligands and their complexes have been determined on the microorganisms which are aligned as Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 14028, Staphylococcus aureus ATCC 25923, Listeria monocytogenes ATCC 19115 and Bacillus cereus ATCC 11778. The complexes, in general, appeared to be more active than their parent ligands. All the activities can be classified as moderate in comparison with the corresponding antibiotic effect on the same bacteria.

2 illus, 2 tables, 31 ref

041985   SRINIVASAN B R, KHANDOLKAR S S, MORAJKAR S M (Goa Univ, Goa - 403 206, Email: srini@unigoa.ac.in) : Structural identification of two differently coordinated heptamolybdate ligands in a hexamagnesium compound. Indian J Chem Sec A 2020, 59A(04), 517-25.

Dissolution of freshly prepared molybdenum trioxide in hot aqueous magnesium carbonate followed by crystallization results in the formation of an all-inorganic heptamolybdate compound viz. [Mg(H₂O)₆]₃[Mg(H₂O)₅(Mo₇O₂₄)][(H₂O)₅Mg (µ₂-Mo₇O₂₄)Mg(H₂O)₅]·6H₂O (1). The crystal structure, spectral characteristics, thermal and electrochemical properties of 1 are reported. Compound 1, which crystallizes in the acentric polar space group Cc, contains six unique Mg(II) ions. The two crystallographically independent heptamolybdate anions function as a monodentate (η1 ) and µ2-bridging bidentate ligand, respectively, forming the anionic [Mg(H₂O)₅(Mo₇O₂₄)]⁴⁻ and [(H₂O)₅Mg(µ₂-Mo₇O₂₄)Mg(H₂O)₅] ²⁻ species, which are charge balanced by three unique hexaaquamagnesium(II) cations. The electrochemical and conductivity studies of 1 reveal the presence of [Mg(H₂O)₆] ²⁺ cations and uncoordinated (Mo₇O₂₄) ⁶⁻ anions in solution. Thermal decomposition of 1 leads to the formation of Mg₂Mo₃O₁₁ via Mg₆Mo₁₄O₄₈ and 3Mg2Mo₃O₁₁·5MoO₃.

4 illus, 4 tables, 44 ref

041984   TUGRUL N, FIRAT E, KIPCAK A S, YILDIRIM M, SENBERBER F T, DERUN E M (Chemical Engineering Dep, Yildiz Technical Univ, Istanbul, Turkey, Email: ntugrul@yildiz.edu.tr) : Thermal dehydration kinetics of non-crystalline manganese borate. Indian J Chem Sec A 2020, 59A(03), 346-50.

In this study, non-crystalline manganese tetrahydric orthoborate (MnH₄(BO₃)₂) has been synthesized by using MnSO₄.H₂O, NaOH and H₃BO₃ via hydrothermal method. The characterizations of the synthesized compounds have been conducted using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Thermal dehydration studies have been conducted using the thermogravimetric analysis (DTG/TG). From the XRD result, it is confirmed that amorphous manganese borate is synthesized and the corresponding characteristic borate vibration are observed in FTIR spectrum shows. A particle size distribution at the micron scale with partially agglomerated state is observed from SEM images. The thermogravimetric results show that dehydration process occurs between the temperatures of 40–270 °C in one-step reaction with average weight loss of 19.26 %. Average activation energies have been determined by using the non-isothermal kinetics methods of Coats-Redfern, Horowitz-Metzger and Van-Krevelen and found as 37.83, 46.54 and 37.88 kJ mol⁻¹, respectively.

4 illus, 2 tables, 27 ref

041983   LAN W, SHI J, ZHOU Z, LIU Q, ZHANG D (Shandong Univ of Technology, Zibo 255049, PR China, Email: dpzhang73@126.com) : Preparation, structural and magnetic characterization of trinuclear and one-dimensional cyanide-bridged Co(III)-Cu(II) complexes. Indian J Chem Sec A 2020, 59A(03), 341-5.

By employing two trans-dicyanocobolt(III) building blocks K[Co(bpb)(CN)₂] (bpb^2- = 1,2-bis(pyridine-2-carboxamido)benzenate), K[Co(bpmb)(CN)₂] (bpmb^2- = 1,2-bis(pyridine-2-carboxamido)-4-methyl-benzenate) and one 14-membered macrocycle Cu(II) compound as assembling segment, two cyanide-bridged Co^III-Cu^II complexes {{[Cu(cyclam)][Co(bpb)(CN)₂]}ClO₄}_n·nCH₃OH·nH₂O (1) and {[Cu(cyclam)][Co(bpmb)(CN)₂]₂}·4H₂O (2) (cyclam = 1,4,8,11-tetraazacyclotetradecane) have been successfully prepared and characterized by elemental analysis, IR spectroscopy and X-ray structure determination. Single X-ray diffraction analysis shows that complex 1 can be structurally characterized as one-dimensional cationic single chain consisting of alternating units of [Cu(cyclam)]²⁺ and [Co(bpb)(CN)₂]^- with free ClO₄^- as balanced anion, while complex 2 presents cyanide-bridged neutral trinuclear bimetallic structure containing Co₂Cu core, giving clear information that the substitute group on the cyanide precursor has obvious influence on the structure type of the target compound. Investigation over magnetic properties of complex 1 reveals the weak antiferromagnetic coupling between the neighboring Cu(II) ions through the diamagnetic cyanide building block.

3 illus, 2 tables, 33 ref

041982   RAGAB A H, AHMED I A, BADER D D (Chemistry Dep, King Khalid Univ, Abha 61413, Saudi Arabia, Email: ahrejab@kku.edu.sa) : Sorption of Cd(II) and Pb(II) ions by nanolimestone from underground water samples from Tehama region of Saudi Arabia. Indian J Chem Sec A 2020, 59A(03), 333-40.

Powdered nano limestone (NLS) has been investigated as an in-expensive adsorbent for removal of heavy toxic metals such as cadmium and lead from aqueous solutions. Batch experiments has been carried out, the favorable pH for maximum metals adsorption is found to be 6.8 for both. The surface area has increased in case of NLS up to 6.2 m²/g. The adsorption capacity calculated by Langmuir equation is found to be 75.1 mg/g for Cd (II) and 68.4 for Pb (II) ions at pH 6.8. The adsorption capacity has increased with temperature and the kinetics followed a First-order rate equation for both. The enthalpy change (ΔH⁰) is 25.4 J mol⁻¹ for Cd (II) and 20.8 J mol⁻¹ for Pb (II), while entropy change (ΔS⁰) is 41.6 J K⁻¹ mol⁻¹ for Cd (II) and 38.7 J K⁻¹ mol⁻¹ Pb (II), which indicate that adsorption process is endothermic and spontaneous in nature. About 25 collected samples of groundwater has been tested and found to be contaminated with cadmium and lead elements with different rates, with using NLS as adsorbent able to remove both metals from the samples. All of the results suggested that the NLS is excellent nano-adsorbents for cadmium and lead contaminated water samples.

6 illus, 5 tables, 44 ref

041981   MOSTAFA M R, MOHAMED G G, MOHAMED M E, FRAG E Y Z (Chemistry Dep, Cairo Univ, Giza, 12613, Egypt, Email: maysa.ramadan140@yahoo.com) : Potentiometric determination of oxybutynin hydrochloride in pharmaceutical formulations at modified carbon paste electrodes. Indian J Chem Sec A 2020, 59A(03), 324-32.

New potentiometric sensitive and selective modified carbon paste (MCPE) electrodes based on ion pair formation between phosphotungestic acid (PTA), sodium tetraphenyl borate (NaTPB), phosphomolybdic acid (PMA) or ammonium reineckate (RN) and oxybutynin hydrochloride (Ox.HCl) has been developed. The proposed electrodes have Nernstian slope values of 58.50±0.71, 58.71±1.20, 54.80±1.30 and 59.20±0.70 mV decade⁻¹ for electrodes modified with 20, 10, 5 and 10 mg of Ox-TPB (electrode I), Ox-RN (electrode II), Ox-PMA (electrode III) and Ox-PTA (electrode IV) ion pairs, respectively. It is found that the dynamic drug concentration range at 25 °C is 1.0×10⁻⁵–1.0×10⁻² mol L⁻¹. The response of MCPEs is pH independent in the range 2.0–6.0 with a fast response time of 10 s for electrode I and 12 s for electrodes II-IV. These electrodes have good Nernstian response in the temperature range 10–60 °C with slope (isothermal coefficient) equal 0.791×10⁻³, 0.769×10⁻³, 0.629×10⁻³ and 1.277×10⁻³ V/°C for electrodes I, II , III and IV respectively. These small values indicate the high thermal stability of the electrodes. The MCPEs have shown a relatively long life time of 36 days. A pure and pharmaceutical formulation of Ox.HCl has quantified using calibration and standard addition methods and the obtained results agreed with that of the official HPLC method. Validation parameters have been optimized according to ICH recommendations. Limits of detection and quantification are calculated under the optimized conditions. For the analytical applications, pharmaceutical dose form has performed. Various interferents have been used to investigate the interference in the analytical application and found that the proposed method would be well adopted for real sample analysis.

4 illus, 6 tables, 36 ref

041979   SAHA S (Chemistry Dep, North Bengal Univ, Darjeeling - 734 013, Email: sanjoychem83@yahoo.com) : New Co(II) and Cu(II) complexes derived from an imidazolium ionic liquid-based Schiff base: synthesis, physico chemical characterization and exploration of antibacterial activities. Indian J Chem Sec A 2020, 59A(03), 311-6.

Two new Co(II) and Cu(II) complexes from an imidazolium ionic liquid based Schiff base 1-{2-(2-hydroxy-5-nitrobenzylideneamino)ethyl}-3-ethylimidazolium tetrafluoroborate have been synthesized and characterized by different analytical and spectroscopic techniques such as elemental analysis (CHN analysis), UV-Visible, ¹H-NMR, FTIR, Mass-spectra, Powder X-ray diffraction analysis, magnetic susceptibility measurements and molar conductance data. From these analytical results, tetra coordinated 1:2 metal-ligand stoichiometry is suggested for the both complexes. The molar conductance data of the complexes reveal their electrolytic nature (1:2). The synthesized complexes along with the ligand have been screened for in vitro antibacterial applications against gram negative and gram positive bacteria to assess their inhibition potentials. The complexes are proved to be very effective against the tested organisms.

4 illus, 46 ref

043915   DUBEY P, ARORA N (Chemistry Dep, Govt m.v.m Bhopal, Madhya pradesh, Email: dubey.pragya22@gmail.com) : Study of phyto chemical screening and in-vitro anti oxidant activity of delonix regia leaves extract. Int J Info Comp Sci 2020, 7(3), 0972-1347.

Phytoconstituents can play an important role in traditional medicines and are under investigation for antibacterial, antimicrobial, and other pharmaceutical functions. The present study is to explore phytoconstituents present in the ethyl acetate extract of Delonix regia (hook) leaves. Methods:-95% of methanol crude extract was further partitioned with different solvents. The ethyl acetate soluble part was subjected to column chromatography and eluted with solvent mixtures of increasing polarity. The structures of these isolated compounds were identified on the basis of spectral analysis. I.e. FT-IR, NMR, UV, VISIBLE, MASS, etc. Result:-95% of methanolic extract of the leaves of Delonix regia the isolation of sterols and glucoside namely,stigmasten-diol-3-o-glucoside,12,15-Dihydroxy-chol-8-en-24-oic acid-3-oxy-6- acetyl-glucoside and sodium, potassium adduct of 12,15-Dihydroxy-5-chol-9-en-24-oic-acid-3- oxy-rhamnosyl-rhamnosyl-rhamnoside, one flavonol, name kaempferol. Conclusion:-On the isolation and identification of chemical constituents from Delonix regia leaves. These molecules would be useful in the treating hyperlipid in patients.

22 ref

043901   HEMALIKA DVD, CHANDRIKA UG (Chemistry Dep, Open Univ of Sri Lanka, Nugegoda, Sri Lanka) : Anti-dengue effects of medicinal plants: A review. Int J Herb Med 2020, 8(6), 50-6.

Dengue viral infections have shown to infect 390 million individuals annually, causing severe clinical disease in the form of dengue hemorrhagic fever (DHF). The World Health Organization (WHO) has identified dengue as one of the top ten global health threats in year 2019. There is currently no specific drug for treatment of this potentially fatal disease. Although a vaccine was recently licensed to prevent infection, it was found to have poor efficacy against some dengue virus (DENV) serotypes. Therefore, researchers are now seeking herbal treatments for the dengue based on ethno medical usage. This review provides information on herbal plants commonly found in tropical countries which documented for antidengue properties by enough scientific experimental details. We hope to encourage more studies on plants described in this review for the development of new therapeutic targets for the management of dengue fever.

2 illus, 1 table, 49 ref

043892   HOSSAIN M M, MAHMOOD S, TANMY T T (Chemistry Dep, Cleveland State Univ, Cleveland, Ohio, USA) : The beneficial effects of green tea on human health: an updated review. Int J Herb Med 2020, 8(5), 63-73.

Green tea is un-fermented product of Camellia species. The leaves of both Camellia sinensis and Camellia assamica, are used for the production of green tea, but C. assamica is mainly used for the production of black tea. Green tea is widely produced from the leaves of C. sinensis, now a day’s which is one of the most popular beverages worldwide. Over the past 50 years or more, scientists have studied this plant with respect to potential health benefits. Research has shown that the main components of green tea that are associated with health benefits are the catechins. The four main catechins found in green tea are: (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), (-)-epigallocatechin (EGC), and (-)- epigallocatechin-3-gallate (EGCG). Of these four, EGCG is present in the largest quantity, and so has been used in most of the researches. Among the important health benefits of green tea are: anticarcinogenic, anti-inflammatory, antioxidant, and antimicrobial properties, and benefits in cardiovascular disease and oral health. Research has been carried out using various animal models and cells lines, and is now more and more being carried out in humans. This type of research will help us to better understand the direct benefits of green tea. This review will focus primarily on researches conducted on human subjects to investigate the health benefits of green tea.

2 illus, 140 ref

043875   WIDYANING E A, RAHAYU I, TIMOTIUS K H (Biochemistry Dep, Krida Wacana Christian Univ, Jakarta, Indonesia) : Ethno medical uses, phytochemistry and pharmacology of Dianella ensifolia (Linnaeus) de Candolle: A systematic review. Int J Herb Med 2020, 8(4), 10-8.

Dianella ensifolia has potential as a source of herbal medicine. The objective of this review is to make an overview of the current knowledge available on the ethno medical uses, phytochemistry and pharmacology of D. ensifolia. Dianella ensifolia is used traditionally in many areas of the world as herbal medicine, especially as topical medicines for ferunculosis, abscesses, lympharingitis, tuberculosis lymphadenitis, tinea, traumatic injuries, and wounds. The plant can also be taken internally in the treatment of dysentery, dysuria, leucorrhoea, blanorrhoea, and fatique. The phytochemical constituents are belonging to phenolic compounds, quinones, flavans, cycloartane-type triterpenoids, steroids, chromones, water soluble carbohydrates, glycosides. The preclinical data are reported for, antioxidant activities, antibacterial, antivirus, anti-inflammation, tyrosinase inhibition. Ethno medical uses of D. ensifolia indicates that aerial and roots are good source of herbal medicine. Phytochemical constituents of aerial and roots are complex with various bioactivities. Pharmacologically, D.ensifolia show its potential as antioxidant, antimicrobial, antiviral, wound healing medicine, and anti melanogenesis.

8 illus, 1 table, 34 ref