@article { ISI:000248376400006, title = {Unusual trisulphide linkage in bromine-thiourea reaction: crystal structure of formamidinium trisulphide complex with bromine}, journal = {Molecular Crystals and Liquid Crystals}, volume = {469}, year = {2007}, month = {SEP}, pages = {69+}, publisher = {TAYLOR \& FRANCIS LTD}, type = {Article}, address = {4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND}, abstract = {

{A new complex of formamidinium trisulphide with bromine has been synthesized. Single-crystal X-ray analysis of this compound revealed a novel trisulphide linkage in the formamidinium trisulphide moiety. The crystals belong to orthorhombic space group Fdd2 with a = 14.9119(15)

}, keywords = {bromine, crystal structure, formamidinium trisulphide, thiourea}, issn = {1542-1406}, doi = {10.1080/15421400701431265}, author = {Tol, Abhaya D. and Natu, Arun D. and Puranik, Vedavati G.} } @article { ISI:000300076200019, title = {Synthesis and stereochemistry of highly crowded N-benzylpiperidones}, journal = {Journal of Molecular Structure}, volume = {1007}, year = {2012}, month = {JAN}, pages = {158-167}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A series of N-benzylated 3,5-diakyl-2,6-diarylpiperidin-4-ones 4-8 were conveniently synthesized in significant yields of 68-88\% by N-benzylation of the corresponding 2,6-diaryl-3,5-dimethylpiperidin-4-ones 1-3 using different benzyl bromides. Initially, the new piperidone 2,6-bis(4-ethoxypheny1)-3,5-dimethylpiperidin-4-one 3 was synthesized by the condensation of 1:1:2 M ratio of 3-pentanone, ammonium acetate and para-ethoxybenzaldehyde in ethanolic medium. All the synthesized new compounds 3-8 were characterized by their analytical and spectral (IR, H-1 and C-13 NMR) interpretations. The stereochemistry of the new piperidone 3 was elucidated as chair conformation with an equatorial orientation of all substituents, suggested by its vicinal couplings from H-1 NMR spectrum. To investigate the impact on piperidone stereochemistry as well as NMR chemical shifts, all the N-benzylated products 4-8 were compared with their corresponding precursors, and as a result, it is clearly established that all the synthesized N-benzyl piperidones exist in the chair conformation with an equatorial orientation of all the substituents at C-2, C-3, C-5, C-6 and N. Contrary to the probability all N-benzylated compounds retain the same conformation and configuration as their precursors, however, a remarkable change on the chemical shifts are observed. For the further unambiguous confirmation of stereochemistry, the 1-benzyl-3,5-dimethyl-2,6-diphenylpiperidin-4-one 4 was examined by single-crystal X-ray diffraction. The compound 4, C26H27NO, crystallized in a P-1 space group under triclinic system with unit cell dimensions a, b, c (angstrom) and alpha, beta, gamma (degrees) of 10.156(2), 11.002(2), 11.348(4) and 116.74(4), 100.81(3), 100.17(3), respectively. (C) 2011 Elsevier B.V. All rights reserved.

}, keywords = {Chair conformation, Configuration, crystal structure, N-benzylation, NMR, Piperidin-4-one}, issn = {0022-2860}, doi = {10.1016/j.molstruc.2011.10.037}, author = {Dindulkar, Someshwar D. and Parthiban, Paramasivam and Puranik, Vedavati G. and Jeong, Yeon Tae} } @article { ISI:000340149800003, title = {Synthesis, characterization, and crystal structure determination of palladacycles of para-substituted 2-thiobenzylazobenzenes}, journal = {Journal of Coordination Chemistry}, volume = {67}, number = {10}, year = {2014}, month = {JUN}, pages = {1702-1714}, publisher = {TAYLOR \& FRANCIS LTD}, address = {4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND}, abstract = {

Bichelated neutral palladacycles (1-3), [Pd(L)Cl], were synthesized from reaction of the new potential tridentate (C,N,S) ligands, 2-thiobenzylazobenzene (L-1), 4{\textquoteright}-methyl-2-thiobenzylazobenzene (L-2), and 4{\textquoteright}-chloro-2-thiobenzylazobenzene (L-3) with sodium tetrachloropalladate(II), Na-2[PdCl4], in ethanol. The compounds were characterized by elemental analysis, FT-IR, H-1 NMR, UV-visible, and thermogravimetric analysis. The crystal structures of L-2 and 1-3 were determined by single-crystal X-ray diffraction. In 1-3, the geometry around palladium remains almost square planar, coordinated to carbon, nitrogen, and sulfur of the ligand forming a bichelated cyclopalladate complex. The C-H center dot center dot center dot Cl type intermolecular hydrogen bonds, weak pi center dot center dot center dot pi, C-H center dot center dot center dot pi, and van der Waals interactions are believed to be the stabilizing forces for the crystal packing of these palladacycles.

}, keywords = {2-Thiobenzylazobenzene, CNS-donor ligand, crystal structure, Palladacycles, Thermogravimetric analysis}, issn = {0095-8972}, doi = {10.1080/00958972.2014.922683}, author = {Bhattacharjee, Tirtha and Kalita, Mukul and Chakravarty, Debamitra K. and Barman, Pranjit and Puranik, Vedavati G.} }