http://nopr.niscpr.res.in/handle/123456789/45786 2026-10-12T12:06:58Z http://nopr.niscpr.res.in/handle/123456789/45791 Title: A fluorescent zinc(II)-based layered complex for selective sensing of Cr₂O₇^2– and Fe³⁺ ions in water system Authors: Zhang, De-Yu; He, Hongming; Zhang, Yu; Wang, Xiu-Guang; Zhao, Xiao-Jun; Yang, En-Cui Abstract: A new Zn(II)-organic framework with 2,2-bipyridine-5,5-dicarboxylate (bpydc) ligand {[Zn(H₂O)(bpydc)]·CH₃OH}_n has been obtained solvothermally, followed by structural and photophysical characterization. Structural analysis reveals that the distorted Zn²⁺ octahedra are periodically extended by the ditopic bpydc^2‒ connector, leading to a coplanar grid-like (4 4) layer. The complex exhibits excellent thermal and environmental stability as well as good dispersion in water system. More interestingly, resulting from the efficient ligand to metal charge transfer, the complex has been observed to emit strong blue emission dispersed in water medium enabling the detection of both Cr₂O₇^2– and Fe³⁺ ions through fluorescence quenching with large quenching constants (1.12X10⁵ M^-¹ and 2.12X10⁴ M^-¹) and low limits of detection (0.54 μM and 1.02 μM). These interesting results suggest that the complex can potentially serve as a promising dual-responsive luminescent sensor material for environmental pollutant monitoring. Page(s): 9-17 2019-01-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/45790 Title: Investigation of structure-property correlation in 2,2′-dipyridyl diselenide based derivatives Authors: Phadnis, Prasad P; Nigam, Sandeep; Mishra, Ratikanta; Wadawale, Amey; Kumar, Mukesh; Kunwar, Amit; Majumder, Chiranjib; Priyadarsini, K I; Jain, Vimal K Abstract: Structure-property correlation in 2,2′-dipyridyl diselenide derivatives has been investigated using four test cases 2,2′-dipyridyl diselenide <strong>(1)</strong>, 2,2′-disleno-bis(3-pyridinol) <strong>(2)</strong>, 2,2′-diseleno-bis(3-carboxypyridine) <strong>(3)</strong> and 2,2′-diseleno-bis (3-nicotinamide) <strong>(4)</strong>. Nature of substituent at C-3 position of pyridyl ring has been found to be a key factor in controlling the molecular structure, its packing capacity and thermal stability of molecular assembly. Strong electron withdrawing group (viz., -COOH, -CONH₂) reduces the charge on selenium and enforces <em>sp²</em> hybridization induced planar molecular configuration. Bent molecules <strong>1 </strong>and<strong> 2</strong> favor denser crystallographic packing in comparison to planar molecule <strong>3 </strong>and<strong> 4</strong>. Thermal investigation reveal that temperature range for thermal decomposition to elemental selenium for <strong>4</strong> and <strong>2</strong> is 210–460 °C and 150–275 °C respectively indicating higher thermal stability of former. The higher thermal stability of <strong>4</strong> has been attributed to secondary intermolecular interactions with the entrapped solvent molecule in the molecular lattice, which is not the case for <strong>2</strong>. The evaluation of these compounds for glutathione peroxidase (GPx) like activity revealed that a stronger electron withdrawing group at C-3 position presented better activity. Thus C-3 position of pyridyl ring of dipyridyl diselenide derivatives can be adopted as one of the focus points for future drug designing processes. Page(s): 18-28 2019-01-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/45789 Title: A new water-soluble Rh(III)-salophen complex as efficient catalyst for alcohol oxidation in aqueous medium Authors: Banik, Biplab; Sarmah, Podma Pollav; Dutta, Abhijit; Mondal, Paritosh; Das, Pankaj Abstract: A new water soluble rhodium(III) complex [Rh(<em>η</em>⁴-<strong>L</strong>)Cl] (<strong>1a</strong>) has been isolated from the reaction between RhCl₃.3H₂O and salophen ligand [<strong>L</strong> = N,N<strong>^′</strong>-bis(salicylidene)-1,2-phenylenediamine (<strong>a</strong>)] in 1:1 molar ratio in dichloromethane solution. The complex <strong>1a </strong>has been characterized by FT-IR, UV-vis, ESI-MS, ¹H and ¹³C NMR spectroscopy. Theoretical calculations (B3LYP) and spectroscopic evidence recommends that the ligand <strong>a</strong> coordinates to the Rh centre through imine N and phenolic O donor atoms. The complex <strong>1a</strong> emerged out to be an effective catalyst for oxidation of alcohols in water. Excellent yields of carbonyl compounds have been acquired for a comprehensive assortment of substrates with H₂O₂ as oxidant at a relatively low loading of catalyst. Thus, the Rh(III)-H₂O-H₂O₂ catalytic system could act as an environmentally benign alternative to oxidation methods in conventional organic solvents. Page(s): 29-35 2019-01-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/45788 Title: Effect of mesoporous ruthenium catalysts for hydrogenation of phenol in vapour phase reactor Authors: Kayalvizhi, Jeevanandham; Pandurangan, Arumugam Abstract: The catalytic behaviour of RuO₂/SBA-15 has been tested in order to cater to the conversion of phenol to cyclohexanone in a fixed bed reactor. Mesoporous SBA-15 has been synthesized by using hydrothermal method. Different weight percentage (3, 5, 7 wt%) of Ruthenia have been loaded on SBA-15 through wet impregnation method. Physico-chemical characterization of material have been meticulously evaluated by XRD, BET and FT-IR and thermal stability of the catalyst confirmed by TGA analysis. TPR results show the decomposition of RuO₂to Ru at 300 °C. The oxidation state and chemical composition of the catalyst have been identified by XPS analysis. The morphology of the catalyst has been identified by using SEM and HR-TEM with EDAX techniques. The catalytic activity has been optimized by tweaking different parameter metrics such as temperature, concentration of catalyst, rate of flow of reactant etc., with different iterations. Ruthenium oxide impregnated on carbon and alumina support (activated carbon and Al₂O₃respectively) has also been examined for hydrogenation reaction and the results compared with that using siliceous support. The maximum conversion of phenol to cyclohexanone has been achieved by passing 4 mL of phenol/h with flow rate of 50 mL of H₂/min (sccm) on 5 wt% at 350 °C using RuO₂/SBA-15 and was confirmed by GC. Lower selectivity of cyclohexanone with decreasing metal loading of RuO₂ on SBA-15 has been observed. Page(s): 36-44 2019-01-01T00:00:00Z