Centro Of Cristallografia Strutturale

Sesto Fiorentino, Italy

Centro Of Cristallografia Strutturale

Sesto Fiorentino, Italy
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Gurumoorthy G.,Annamalai University | Rani P.J.,Annamalai University | Thirumaran S.,Annamalai University | Ciattini S.,Centro Of Cristallografia Strutturale
Inorganica Chimica Acta | Year: 2017

Five homoleptic complexes of general formula [Co(S2CNRR′)3] [where R = furfuryl; R′ = cyclohexyl (1), benzyl (2), furfuryl (3), methylferrocenyl (4), 2-phenylethyl (5)] were prepared and studied by FT-IR, UV–vis and NMR (1H and 13C) spectroscopy. A single crystal X-ray structural analysis was carried out for complex 3. Electronic spectral studies suggest octahedral geometry for all the complexes. In the molecular structure of 3, cobalt atom coordinates to three N,N-difurfuryldithiocarbamate ligands in the S,S′-bidentate mode, forming an octahedral polygon [CoS6]. DFT calculations were carried out for 3. The ability of complex 4 containing redox-active ferrocene moiety to sense anions (benzoate, F−, Br− and I−) was examined by cyclic voltammetric titration studies. This study reveals that complex 4 prefer to bind with Br− Complexes 3, 4 and 5 were utilized for the preparation of cobalt sulfide (3 and 5) and cobalt-iron sulfide (4) nanoparticles. The as-prepared nanoparticles were characterized by PXRD, TEM, EDS, UV–vis and FT-IR spectroscopy. TEM image of cobalt-iron sulfide nanoparticles reveals that the particles are cuboid. The blue shift in the absorption maxima in the UV–vis spectra of cobalt sulfide and cobalt-iron sulfide is attributed to the consequence of the quantum confinement effect. Photocatalytic activities of as-prepared nanoparticles were studied by decolourization of methylene green and rhodamine-B under ultraviolet light. It was found that the cobalt-iron sulfide degrades methylene green and rhodamine-B much faster than cobalt sulfide. © 2016 Elsevier B.V.


Selvaganapathi P.,Annamalai University | Thirumaran S.,Annamalai University | Ciattini S.,Centro Of Cristallografia Strutturale
Journal of Molecular Structure | Year: 2017

Three new phenylmercury(II) dithiocarbamate complexes incorporating the furyl moiety, namely (N,N-difurfuryldithiocarbamato-S,S′)phenylmercury(II) (1), (N-furfuryl-N-(4-chlorobenzyl)dithiocarbamato-S,S′)phenylmercury(II) (2), and (N-furfuryl-N-(2-phenylethyl)dithiocarbamato-S,S′)phenylmercury(II) (3) have been prepared and characterized by elemental analysis, IR, 1H, and 13C NMR spectroscopy and X-ray crystallography. The crystal structures of 1, 2 and 3 show a linear mercury(II) core at the centre of the molecules. Weak intermolecular Hg⋯S interactions in 2 and 3 lead to the formation of linear chain and head to tail dimers, respectively. The Hirshfeld surface analysis and the associated 2D fingerprint plots of 1–3 have been also studied to evaluate intermolecular interactions. Theoretical calculations of isolated molecules of 1–3 have been performed using DFT method at B3LYP-LANL2DZ basis set. The geometrical parameters of 1–3 are in a good agreement with those obtained from the XRD experiment. The energy gap between EHOMO and ELUMO have been calculated. The molecular electrostatic potential (MEP) analysis support the substantial contribution of the resonance structure R1R2N+ = CS2 2− to the description of their structures. Complex 1 has been utilized as single source precursor to afford mercury sulfide nanoparticles via solvothermal decomposition in ethylenediammine. The as-prepared HgS nanoparticles were characterized using powder X-ray diffraction (PXRD), Transmission electron microscopy (TEM), Energy dispersive X-ray spectra (EDS) and Diffuse reflectance spectra(DRS). The band gap energy calculated from DRS spectrum shows evidence of quantum confinement. © 2017 Elsevier B.V.


Selvaganapathi P.,Annamalai University | Thirumaran S.,Annamalai University | Ciattini S.,Centro Of Cristallografia Strutturale
Journal of Sulfur Chemistry | Year: 2017

[Zn(4-mbzdtc)2] (1), [Zn(4-mbzdtc)2(py)] (2), [Zn2(4-mbzdtc)4(4,4′-bipy)] (3), and [Zn(4-mbzdtc)2(2,2′-bipy)] (4), (where, 4-mbzdtc = N,N-di(4-methoxybenzyl)dithiocarbamate) were prepared and characterized by elemental analysis, infrared, 1H and 13C NMR spectroscopy and the structures of 1 and 3 were elucidated by X-ray crystallography. The monomeric structure of 1 shows a distorted tetrahedral geometry for zinc(II). The coordination geometry around zinc in dinuclear complex 3 is an intermediate between square pyramidal and trigonal bipyramidal. The downfield shift of NCS2 carbon signal for imine adducts of 2–4 compared to those found in parent complex 1 is attributed to the change in coordination number and steric effect exerted by the nitrogen donor ligand. Hirshfeld surface analysis was used to visualize intermolecular interactions in the crystal structure of 1 and 3. The geometry optimization of 1 is performed using DFT with the B3LYP-LANL2DZ basis set. Solvothermal decomposition of 1 yielded only hexagonal zinc sulfide nanoparticles. Zinc sulfide nanoparticles were characterized using powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectra and diffuse reflectance spectra. DRS study of ZnS nanoparticles shows the quantum confinement effect with a band gap of 3.74 eV. © 2017 Informa UK Limited, trading as Taylor & Francis Group


Selvaganapathi P.,Annamalai University | Thirumaran S.,Annamalai University | Ciattini S.,Centro Of Cristallografia Strutturale
Phosphorus, Sulfur and Silicon and the Related Elements | Year: 2017

Bis(N-butyl-N-(4-fluorobenzyl)dithiocarbamato-S,S')nickel(II) (1) and (N-butyl-N-(4-fluorobenzyl)dithiocarbamato-S,S')(thiocyanato-N)(triphenylphosphine)-nickel(II) (2) have been prepared. Both the complexes have been characterized by elemental analyses, IR, electronic and 1H and 13C NMR spectroscopy. Single crystal X-ray analysis of complex 2 showed a distorted square planar configuration around the nickel atom due to steric effect of the triphenylphosphine and the bidentate chelation by two sulfur atoms of the dithiocarbamate ligand. UV-Vis spectral data of 1 and 2 are consistent with the formation of square planar nickel(II) complexes. Hirshfeld surface analysis was also carried out to provide qualitative and quantitative insights into the intermolecular interactions in 2. Molecular electrostatic potential surface map reveals that the negative charge is delocalized over S atoms of NCS2 and the positive charge is localized over N atom of NCS2 group. This indicates the considerable double bond character of the C-N (thioureide) bond. Nickel sulfide nanoparticles have been prepared from complex 1 and characterized using PXRD, EDS, UV-DRS, and SEM. EDS analysis confirm the formation of nickel sulfide. © 2017 Taylor & Francis Group, LLC


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.


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.


Valarmathi P.,Annamalai University | Thirumaran S.,Annamalai University | Ragi P.,Annamalai University | Ciattini S.,Centro Of Cristallografia Strutturale
Journal of Coordination Chemistry | Year: 2011

[M(4-epzdtc) 2(py)], [M(4-epzdtc) 2(1,10-phen)], and [M(4-epzdtc) 2(2,2″-bipy)] (where M=Zn(II), Cd(II); 4-epzdtc -=4-ethylpiperazinecarbodithioate) were synthesized and characterized by IR and NMR ( 1H, 13C, HSQC and HMBC) spectra. A single-crystal X-ray analysis was carried out for [Zn(4-epzdtc) 2(py)]. The N 13CS 2 chemical shifts of [M(4-epzdtc) 2] and its adducts follow the order: [M(4-epzdtc) 2] (ca 202 ppm)5[M(4-epzdtc) 2(py)] (ca 204 ppm)< [M(4-epzdtc) 2(N,N)] (N,N=1,10-phen, 2,2″-bipy) (ca 206 ppm), due to the change in coordination number. Single-crystal X-ray structural analysis of [Zn(4-epzdtc) 2(py)] showed that zinc is five-coordinate with four sulfurs from dithiocarbamate and one nitrogen from pyridine. This complex adopts a geometry intermediate between the tetragonal pyramid (C 4v) and trigonal bipyramid (D 3h). [Cd(4-epzdtc) 2] and its adducts were used as single source precursors for preparation of CdS. The as-prepared CdS was characterized by powder X-ray diffraction, UV-Vis absorption, and fluorescence spectroscopy. The UV-Vis absorption spectra of CdS particles indicate a blue shift in the absorption spectra due to the quantum size effect. © 2011 Taylor & Francis.


Srinivasan N.,Annamalai University | Thirumaran S.,Annamalai University | Ciattini S.,Centro Of Cristallografia Strutturale
Journal of Molecular Structure | Year: 2012

[Cd(thqdtc) 2(1,10-phen)] (1) and [Cd(thqdtc) 2(2, 2′-bipy)] (2) (where thqdtc = 1,2,3,4-tetrahydroquinolinedithiocarbamate, 1,10-phen = 1,10-phenanthroline and 2,2′-bipy = 2,2′-bipyridine) have been synthesized from [Cd(thqdtc) 2] (3). The downfield shift of N 13CS 2 carbon signal for 1 (209.8 ppm) and 2 (209.7 ppm) from the chemical shift value of 3 (208.2 ppm) is attributed to the increase in coordination number. Single crystal X-ray structures of 1 and 2 indicate that the central metal atom is in distorted octahedral environment for both complexes. The presence of added neutral ligand in the coordination sphere of 3 increases Cd-S distances in 1 and 2. S-Cd-S angles are not affected. The complex 1 has been used as precursor for the preparation of CdS nanoparticles. The CdS nanoparticles have been characterized by powder XRD, TEM and UV-vis spectroscopy. The quantum-confined CdS nanorods with diameter of ca. 7 nm and length ranging from 50 to 75 nm have been grown from 1 with diethylenetriamine. © 2012 Elsevier B.V. All rights reserved.


Srinivasan N.,Annamalai University | Thirumaran S.,Annamalai University | Ciattini S.,Centro Of Cristallografia Strutturale
RSC Advances | Year: 2014

[Hg(thqdtc)2] (1) and [Hg(thqdtc)2(2,2′-bipy)] (2) (where thqdtc = 1,2,3,4-tetrahydrquinolinecarbodithioate and 2,2′-bipy = 2,2′-bipyridine) have been prepared and characterized. Single crystal X-ray structural analysis show that [Hg(thqdtc)2]·0.5(2, 2′-bipy) (3), [Hg(thqdtc)2]·0.25C2H 5OH (4) and [Hg3(thqdtc)6]·py (5) exist as monomer, dimer and trimer, respectively. Co-crystallization of 2,2′-bipyridine, ethanol and pyridine (py) with [Hg(thqdtc)2] causes a change in secondary interactions and hence, different structural motifs are obtained. Complexes 1 and 2 have been used as single source precursors for the preparation of HgS nanoparticles. The nanoparticles have been characterized by XRD, TEM, UV and fluorescence spectra. Use of 1 for the preparation of mercury sulfide afforded hexagonal shape HgS nanosheets and three different morphology HgS nanoparticles are obtained from 2; most of the crystallites are rod while the remainders are hexagonal and rectangle sheets. © 2014 the Partner Organisations.


Rani P.J.,Annamalai University | Thirumaran S.,Annamalai University | Ciattini S.,Centro Of Cristallografia Strutturale
Phosphorus, Sulfur and Silicon and the Related Elements | Year: 2013

Six new nickel complexes of two dithiocarbamate ligands (cyfdtc = N-cyclohexyl-N- furfuryldithiocarbamate and bztpedtc = N-benzyl-N-[2- thiophenylethyl]dithiocarbamate) namely, (Ni[cyfdtc]2) (1), (Ni[bztpedtc]2) (2), (Ni[cyfdtc][NCS][PPh3]) (3), (Ni[bztpedtc] [NCS][PPh3]) (4), (Ni[cyfdtc][PPh3]2)ClO4 (5), and (Ni[bztpedtc][PPh3]2)ClO4 (6) have been prepared and characterized using IR, electronic, and NMR (1H and 13C) spectra. A single crystal X-ray structural analysis was carried out for complex 3 and showed that nickel is in a distorted square planar arrangement with the NiS2PN chromophore. The shift in νCN of the heteroleptic complexes to higher frequencies compared with the parent complex is assigned to mesomeric delocalization of electron density from the dithiocarbamate ligand toward the metal atom, which increases the contribution of polar thioureide form in mixed ligand complexes. Electronic spectral studies suggest square planar geometry for the complexes. In the 13C NMR spectra, the upfield shift of NCS2 carbon signal for 3 and 4 from the chemical shift value of 1 and 2 is due to effect of PPh3 on the mesomeric drift of electron density toward nickel throughout thioureide CN bond. © 2013 Taylor and Francis Group, LLC.

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