Ag(i), Cu(ii), Co(iii) and Hg(ii) complexes and metal-assisted products derived from 4-methyl-piperidine-carbodithioate: syntheses, structures, thermal analyses, redox behaviour and fluorescence properties. Issue 96 (30th September 2016)

• Record Type: Journal Article
• Authors: Nath, Paras; Bharty, M. K.; Maiti, B.; Bharti, A.; Butcher, R. J.; Wikaira, J. L.; Singh, N. K.
• Is Part Of: RSC advances. Volume 6:Issue 96(2016)
• Page Start: 93867
• Page End: 93880
• Publication Date: 2016-09-30
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra15186h
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Ag(i ), Cu(ii ), Co(iii ) and Hg(ii ) complexes and metal-assisted products derived from 4-methyl piperidine have been synthesized. The Cu(ii ) complex is redox reversible and compounds3 and5 are fluorescent. Abstract : Four new complexes [Ag2 (4-mpipdtc)2 (PPh3 )2 ] (1 ), [Cu(4-mpipdtc)2 ] (2 ), [Co(4-mpipdtc)3 ]·CHCl3 (3 ) and [PhHg(4-mpipdtc)] (4 ) and two new products, bis(4-methyl piperidinethiocarbonyl) disulfide {(4-mpipdtc)2 } (5 ) and (4-methyl-piperidin-1-yl) carbothioylsulfanyl-methyl (4-methyl)-piperidine-1-carbodithioate {CH2 (4-mpipdtc)2 } (6 ) have been obtained in this study. The syntheses of compounds5 and6 were assisted by Mn(ii ) and Ag(i ) ions, respectively, and were obtained from potassium 4-methyl-piperidine-carbodithioate {K + (4-mpipdtc) − } {where, 4-mpipdtc − = 4-methyl piperidine carbodithioate}. All new compounds have been characterized by elemental analyses, IR, NMR, magnetic susceptibility and single X-ray crystallography techniques. These compounds are stabilized by intermolecular C–H⋯S, S⋯S, C–H⋯π and C–H⋯N interactions. The most interesting feature in complex4 is that the ligand bound phenylmercury cation is stabilized via intermolecular as well as intramolecular Hg⋯S secondary interactions. Compounds3 and5 are highly fluorescent in a solution when compared to the free ligand and emit violet/violet-blue light at 372 and 413 nm upon excitation at 328 and 300 nm, respectively. The course of the thermal degradation of complexes1–4 have been investigated by TG-DTA, which indicates that metal sulphide is formed as the final residue. The results obtained from the electronic structure calculations at the density functional theory level corroborate our experimental findings obtained from the IR data. Frontier molecular orbital analysis reveals that complexes1 and3 are softer and more reactive than complexes2 and4 . Cyclic voltammetry shows that complex2 exhibits a reversible Cu(ii )/Cu(i ) redox process at 0.515 V, whereas the ligand and complexes1, 3 and4 show irreversible redox behaviour.