Entity

Time filter

Source Type

Sesto Fiorentino, Italy

Gomathi G.,Annamalai University | Thirumaran S.,Annamalai University | Ciattini S.,Centro Of Cristallografia Strutturale
Polyhedron | Year: 2015

Two new homoleptic complexes, [Tl(bzfdtc)]2 (1) and [Tl(bu2-OHbzdtc)]2 (2) (where bzfdtc = N-benzyl-N-furfuryldithiocarbamate and bu2-OHbzdtc = (N-butyl-N-(2-hydroxybenzyl)dithiocarbamate), have been prepared and characterized by IR, NMR (1H and 13C), UV-Vis spectroscopy, cyclic voltammetry and single crystal X-ray structural analysis. X-ray crystallography revealed that both complexes are dimers. Both complexes show two monohapta Tl⋯C(S2) interactions. The Tl⋯Tl distances are 3.635 and 3.719 Å for 1 and 2, respectively. The phenyl ring of the bzfdtc ligand is coordinated (by a η6 interaction) to the Tl+ ion in complex 1. A rare intramolecular anagostic C-H⋯Tl interaction is observed in complex 2. Thallium sulfide nanoparticle samples 3 and 4 have been prepared from complex 1 using conventional heating and microwave irradiation, respectively. Samples 3 and 4 have been characterized by PXRD, EDAX, HR-TEM, UV-Vis absorption and fluorescence spectroscopy. PXRD measurements revealed rhombohedral and hexagonal phases for samples 3 and 4, respectively. EDAX confirmed the formation of Tl2S. HR-TEM images showed that the size and morphology of the Tl2S nanoparticles are affected by the method of preparation (conventional heating compared to microwave irradiation). © 2015 Elsevier Ltd. All rights reserved. Source


Srinivasan N.,Annamalai University | Valarmathi P.,Annamalai University | Thirumaran S.,Annamalai University | Ciattini S.,Centro Of Cristallografia Strutturale
Transition Metal Chemistry | Year: 2010

Three complexes of a dithiocarbamate ligand (dbpdtc = benzyl(4- (benzylamino)phenyl)dithiocarbamate), namely [Ni(dbpdtc)2] (1), [Ni(dbpdtc)(NCS)(PPh3)] (2) and [Ni(dbpdtc)(PPh3) 2]ClO4 (3) have been prepared. The complexes were characterized by IR, electronic spectroscopy and cyclic voltammetry. A single-crystal X-ray structural analysis was carried out for complex 1 and showed that the nickel is in a distorted square planar environment with a NiS4 chromophore. For the two mixed ligand complexes, the thioureide ν C-N values were shifted to higher wavenumbers compared to [Ni(dbpdtc)2], suggesting increased strength of the thioureide bond due to the presence of the π-accepting phosphine. Electronic spectral studies suggest square planar geometries for the complexes. Cyclic voltammetry showed easier reduction of nickel(II) to nickel(I) in the mixed ligand complexes compared to [Ni(dbpdtc)2]. © 2010 Springer Science+Business Media B.V. Source


Srinivasan N.,Annamalai University | Thirumaran S.,Annamalai University | Ciattini S.,Centro Of Cristallografia Strutturale
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2013

(2,2′-Bipyridine)bis(1,2,3,4-tetrahydroquinolinecarbodithioato-S, S′)zinc(II), [Zn(thqdtc)2(2,2′-bipy)] (1) has been synthesized from bis(1,2,3,4-tetrahydroquinolinecarbodithioato-S,S′) zinc(II), [Zn(thqdtc)2] (2) and characterized by elemental analysis, IR and NMR spectroscopy and single crystal X-ray analysis. In the 13C NMR spectrum, complex 1 showed a single low-field resonance associated with back bone carbon of dithiocarbamate (N13CS2) at 209.2 ppm. Single crystal X-ray analysis of 1 showed that the zinc ion is in a distorted octahedral environment of two nitrogen atoms and four sulfur atoms around it. The complex 1 has been used as single source precursor for the preparation of ZnS nanosheets via solvothermal method. The ZnS nanosheets have been characterized by powder XRD, EDAX, TEM, UV-Vis and fluorescence spectroscopy. TEM studies indicate that the nanosheets are very thin. The nanosheets obtained show quantum size effect in their UV-Vis absorption spectrum. The strong emission peak centered at 415 nm in fluorescence spectrum could be attributed to the electron-hole recombination from internal vacancies for Zn and S atoms. © 2012 Elsevier B.V. All rights reserved. Source


Srinivasan N.,Annamalai University | Thirumaran S.,Annamalai University | Ciattini S.,Centro Of Cristallografia Strutturale
Journal of Molecular Structure | Year: 2014

(1,10-phenanthroline)bis(1,2,3,4-tetrahydroquinolinecarbodithioato-S,S′)mercury(II); [Hg(thqdtc)2(1,10-phen)] (1); has been synthesized and characterized by elemental analysis, IR and NMR spectroscopy and single crystal X-ray analysis. IR spectrum of the complex reveals the contribution of thioureide form to the structure. In the 13C NMR spectrum, [Hg(thqdtc)2(1,10-phen)] shows a single low-field resonance associated with backbone carbon of dithiocarbamate (N13CS2) at 205.7 ppm. The mononuclear structure of [Hg(thqdtc)2(1,10-phen)] exhibits monodentate and bidentate coordination by dithiocarbamate ligands and an intermediate geometry between tetragonal pyramidal and trigonal bipyramidal for mercury, defined by an N2S3donor set. [Hg(thqdtc)2(1,10-phen)] has been found to be an effective single-source precursor for the preparation of α-HgS nanosheets via solvothermal method. The as-prepared HgS nanosheets have been characterized by powder XRD, TEM, UV-Vis and fluorescence spectroscopy. TEM image of HgS exhibits that the as-prepared HgS particles are hexagonal shaped nanosheets. UV-Vis spectroscopy established pronounced quantum confinement effect. © 2014 Elsevier B.V. All rights reserved. Source


Jamuna Rani P.,Annamalai University | Thirumaran S.,Annamalai University | Ciattini S.,Centro Of Cristallografia Strutturale
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

Seven complexes of a new dithiocarbamate ligand (ftpedtc = (furan-2-yl)methyl(2-(thiophen-2-yl)ethyl)dithiocarbamate) namely [Ni(ftpedtc)2] (1), [Ni(ftpedtc)(NCS)(PPh3)] (2), [Ni(ftpedtc)(PPh3)2]ClO4 (3), [Zn(ftpedtc)2] (4), [Zn(ftpedtc)2(py)] (5), [Zn(ftpedtc)2(1,10-phen)] (6) and [Zn(ftpedtc)2(2,2′-bipy] (7) have been prepared. The complexes were characterized by IR, UV-Vis and NMR (1H and 13C) spectroscopy. Single crystal X-ray structural analysis was carried out for complexes 5 and [Zn(ftpedtc)Cl(1,10-phen)] (8). Electronic spectral studies suggest square planar geometry for nickel complexes. The 13C NMR peaks of the group N13CS2 are found in all the cases, at around 205.0 ppm, which indicates the bidentate character of the dithiocarbamate ligand. X-ray structures of 5 and 8 show bidentate coordination by dithiocarbamate ligands and a distorted trigonal bipyramidal geometry for zinc, defined by NS4 and ClN2S2 donor sets, respectively. The packing in 8 involves π-π stacking interactions involving the 1,10-phenanthroline ring systems with the distance between ring centroids being 3.587 Å. © 2014 Elsevier B.V. All rights reserved. Source

Discover hidden collaborations