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[Ni(mdtc)(1,3-dppp)]ClO4 (1), and [Ni(mdtc)(1,4-dppb))ClO4 (2) [(mdtc−=4-morpholinecarbodithioato anion, 1,3-dppp=1,3-bis(diphenylphosphino)propane, 1,4-dppb=1,4-bis(diphenylphosphino)butane)] have been prepared from their parent dithiocarbamate. The planar complexes were characterized by electronic and IR spectra. Single crystal X-ray structures of compounds 1 and 2 were determined. Both the complexes have planar NiS2P2 chromophores in keeping with the observed diamagnetism. In complexes 1 and 2 the NiS and NiP distances are symmetric. The thioureide CN distances of both the complexes show a decreasing trend compared to the CN distance in the parent Ni(mdtc)2. The resulting PNiP angles are higher in both the complexes (96.5(1)° in 1, 101.4(8)° in 2) due to puckering of propane and the butyl alkyl chain associated with 1,3-dppp and 1,4-dpppb.

Synthesis, spectral and cyclic voltammetric characterization of [Zn2(deadtc)4(4,4′-bipy)] (1) (deadtc=di(2-hydroxyethyl)dithiocarbamate anion) and [Zn2(nmedtc)4(4,4′-bipy)] (2) (nmedtc=N-methyl, N-ethanoldithiocarbamate anion) are reported. The single crystal X-ray structures of the adducts have also been determined. IR spectra of complexes 1 and 2 show the thioureide ν(CN) bands at 1480 and 1489 cm−1, respectively which are lower than the values observed for the parent dithiocarbamates. A reduction in the thioureide stretching frequency is due to the increase in coordination around the zinc ion and the resultant increase in electron density. The charge transfer transitions are observed in the region 260–320 nm. The X-ray crystal structures show that the two adducts are dimeric in nature. The zinc ions are five coordinated with the ZnS4N coordination environment in both complexes. Both adducts have two short ZnS bonds which are close to those observed in the respective parent dithiocarbamate. The asymmetry introduced in ZnS bond lengths in both adducts is due to the coordination of nitrogen from the 4,4′-bipyridine moiety. The ZnN distances are 2.072(4) and 2.054(8) A for compounds 1 and 2, respectively. In complex 1, two sets of thioureide CN distances are observed; one set averages to 1.328(5) A and the other which is longer, averages to 1.346(6) A. In complex 2 the thioureide CN distance (mean of C(6)N(7) and C(12)N(13)) is 1.339(48) A) indicates the partial double bond nature. However, a longer CN distance (C(6)N(7)′:1.374(75) A) is also observed due to the disorder associated with the aliphatic chain of the ethanolic group on dithiocarbamate. All the CS distances are symmetric in both complexes. Two of the CS distances, namely S(3)C(6) (1.702(5) A) in complex 1 and S(2)C(6) (1.706(11) A) in 2, are different. The cyclic voltammetric studies show clearly the presence of excess electron density on the zinc ions in both adducts compared to the parent dithiocarbamates.

The chelating properties of two polyfunctional di-2-pyridylketone hydrazone ligands toward the copper ion have been investigated in mono- and bimetallic complex species. The complexation reaction is strongly influenced by the nature of the inorganic salt reagent. Structural characterization of the mono- and bimetallic copper species by powder X-ray diffraction analysis and computer simulation made an important contribution to the discovery of the synthesis conditions. Simulated IR and 1H NMR spectra were also calculated.