http://nopr.niscpr.res.in/handle/123456789/42573 2026-10-10T01:34:00Z 2026-10-10T01:34:00Z Kumar, Arun Banerjee, Samya Mukherjee, Sanjoy Chakravarty, Akhil R http://nopr.niscpr.res.in/handle/123456789/42580 2017-08-09T09:14:37Z 2017-08-01T00:00:00Z

Title: Vitamin-B6 Schiff base dioxovanadium(V) complex for targeted visible light-induced anticancer activity Authors: Kumar, Arun; Banerjee, Samya; Mukherjee, Sanjoy; Chakravarty, Akhil R Abstract: A dioxovanadium(V) complex of vitamin-B6 Schiff base [VO₂L] (<b>1</b>) (where H₂L·HCl is 3-hydroxy-5-(hydroxymethyl)-4-(((2-hydroxyphenyl)imino)methyl)-2-methylpyridin-1-ium chloride) has been prepared and structurally characterized. Its photo-induced cytotoxicity and mechanism of cell death has been studied. Single crystal X-ray structure shows five-coordinate square-pyramidal geometry of the complex having the dianionic O,N,O-donor tridentate vitamin-B6 Schiff base and two <i>cis</i>-oriented oxo ligands bound to V(V). DFT study shows the HOMO located on the amino-phenolic moiety, while the LUMO is on the protonated aromatic unit, i.e., the pyridiniumphenolate moiety. Vitamin-B6 transporting membrane carrier (VTC) pathway seems to be responsible for the higher cellular uptake and activity of the complex into the cervical HeLa and breast cancer MCF-7 cells in preference to the normal embryonic fibroblast 3T3 cells. The complex exhibits reactive oxygen species (ROS) mediated apoptotic photocytotoxicity in visible light of 400–700 nm in the cancer cells (IC₅₀: ~16 μ<i>M</i>), while being essentially non-toxic in the dark. Alkaline Comet assay shows damage of the nuclear DNA. Page(s): 805-813

2017-08-01T00:00:00Z Abbasoglu, Rza Atalay, Abdurrahman http://nopr.niscpr.res.in/handle/123456789/42579 2017-08-09T09:09:24Z 2017-08-01T00:00:00Z

Title: DFT study of the mechanism and stereochemistry of electrophilic transannular addition reaction of bromine to 6-oxa-heptacyclo[9.6.2.2^3,9.1^13,16.0^2,10.0^4,8.0^12,17]docosan-14,18,20-triene-12,17-dicarboxylic anhydride Authors: Abbasoglu, Rza; Atalay, Abdurrahman Abstract: The geometry and the electronic structure of 6-oxa-heptacyclo[9.6.2.2^3,9.1^13,16.0^2,10.0^4,8.0^12,17] docosan-14,18,20-triene-12,17-dicarboxylic anhydride (HDTD) have been investigated by DFT methods. The study shows that the norborneyl double bond of the HDTD molecule is endo pyramidalized and the central and bicyclo[2,2,2]octenyl double bonds are exo pyramidalized. The structure and stability of the cation intermediates and products of the reaction have been investigated by DFT methods. The most stable cation intermediate is U-N-type ion and the reaction takes place over this cation. The cation centre of U-N-type ion mutually interacts with the unshared electron pair of the oxygen atom of the tetrahydrofuran ring on the exo face and is sterically hindered by the tetrahydrofuran ring. The nucleophilic attack of bromide anion (Br^–) on the cation centre of U-N-type ion occurs on the endo face and as a result the exo,endo-dibromide isomer of U-N-type product is obtained, which is 6.913 kcal mol^-1 more stable than the exo,exo-isomer. Page(s): 814-820

2017-08-01T00:00:00Z Sonkar, Piyush Kumar Ganesan, Vellaichamy Singh, Ravi Kant Yadav, Dharmendra Kumar Gupta, Rupali Yadav, Mamta http://nopr.niscpr.res.in/handle/123456789/42578 2017-08-09T07:28:59Z 2017-08-01T00:00:00Z

Title: Single walled carbon nanotubes decorated vanadyl phthalocyanine composite for electrochemical oxygen reduction in fuel cells Authors: Sonkar, Piyush Kumar; Ganesan, Vellaichamy; Singh, Ravi Kant; Yadav, Dharmendra Kumar; Gupta, Rupali; Yadav, Mamta Abstract: Vanadyl phthalocyanine (VOPc) has been immobilized on single walled carbon nanotubes by the adsorption process and characterized using UV-vis spectroscopy, infrared spectroscopy and X-ray diffraction techniques. Electrochemical characterization of VOPc immobilized SWCNTs (SWCNTs-VOPc) has been done by coating an aqueous colloid of SWCNTs-VOPc on glassy carbon electrode (represented as GC/SWCNTs-VOPc). GC/SWCNTs-VOPc exhibits a pair of peaks at –265 and –97 mV (at 20 mV s^-1 in 0.1 <i>M</i> H₂SO₄) due to the characteristic redox process, V^IV/III of VOPc. Further, electrocatalytic reduction of oxygen is analysed using GC/SWCNTs-VOPc electrode by cyclic voltammetry. GC/SWCNTs-VOPc electrode efficiently reduces oxygen in 0.1 <i>M</i> H₂SO₄ with a low onset potential of 0.16 V. Also, GC/SWCNTs-VOPc exhibits significant storage stability, retaining 91% of its original catalytic reduction current after 10 days storage at room temperature in air and dry conditions. Page(s): 821-825

2017-08-01T00:00:00Z Xin, Ling-Yun Li, Yun-Ping Ju, Feng-Yang Li, Xiao-Ling Liu, Guang-Zhen http://nopr.niscpr.res.in/handle/123456789/42577 2017-08-09T07:17:12Z 2017-08-01T00:00:00Z

Title: A supramolecular microporous network of zinc(II) coordination polymer for highly selective fluorescent detection of Pb²⁺ Authors: Xin, Ling-Yun; Li, Yun-Ping; Ju, Feng-Yang; Li, Xiao-Ling; Liu, Guang-Zhen Abstract: A hydrogen bonded microporous network with Lewis basic N sites, viz., {[Zn(TZ-HIP)(HPYTZ)(H2O)2]·3H₂O}_n [TZ-HIP = 5-(tetrazol-5-yl)isophthalic acid, HPYTZ = 3,5-di(4-pyridyl)-1H-1,2,4- triazolate ligand] has been obtained from the dual ligand system of polydentate N-heterocyclic carboxylate and dipyridyl-type ligands. Single crystal X-ray diffraction analysis shows that the adjacent Zn(II) centers are bridged by HTZ-H₂IP ligand to form 1D chain with HPYTZ molecules as free lateral arms. The paralleled chains are connected by H-bonding interactions to produce the 3D microporous network with 1D pores. It is interesting that the uncoordinated N atoms (Lewis base sites) pores cause Pb²⁺ ions to produce a remarkably enhancing effect on the luminescent intensity of the zinc complex with high sensitivity in the detection range of 10^-3-10^-5mol L^-1 concentration limit. This coordination polymer may be used as a sensing material for developing a highly selective and sensitive Pb²⁺ sensor in the biological and environmental materials. Page(s): 826-831

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