Synthesis and structural studies on Ni(II) dithiocarbamates : Exploring intramolecular Ni···H-C interactions

Abstract

Five new Ni(II) dithiocarbamates with NiS4, NiS2PN and NiS2PCl coordination spheres, viz. [Ni(bupmbzdtc)2] (1), [Ni(bupmbzdtc)(PPh3)(NCS)] (2), [Ni(bupmbzdtc)(PPh3)Cl] (3), [Ni(4-dpmpzdtc)(PPh3)Cl] (4) and [Ni(pbbzbudtc)(PPh3)(NCS)] (5), where bupmbzdtc = N-butyl(p-methylbenzyl)dithiocarbamato anion, 4-dpmpzdtc = 4-(diphenylmethyl)piperazinecarbodithioato anion, pbbzbudtc = N-(p-bromobenzyl)butyl-dithiocarbamato anion and PPh3 = triphenylphosphine, were synthesized and characterized by UV, IR, NMR and single crystal X-ray diffraction methods. Spectral results suggest a square planar geometry around the Ni(II) metal center for all the synthesized complexes. Single crystal X-ray structural analyses agree to these findings, but also show evidence of intramolecular C–H⋯Ni interactions in complexes 3 and 5 (2.801 and 2.872 Å respectively) in the solid state, analyzed further by computational (DFT) methods. Herein, these and other structural aspects of the homo- (1) and heteroleptic dithiocarbamate complexes (2–5) of Ni(II) are discussed.