Natural abundance 15N and 13C CP/MAS NMR of dialkyldithiocarbamate compounds with Ni(II) and Zn(II)

Different symmetrically substituted and cyclic dialkydithiocarbamate (R=CH3, C2H5, C3H7, i-C3H7, C4H9, i-C4H9 and R-2=(CH2)(5), (CH2)(6), (CH2)(4)O) compounds, such as tetraalkylthiuram disulfides, mononuclear nickel(II), binuclear zinc(II) and heteropolynuclear complexes and their adducts (both non-solvated and solvated forms) with planar and non-planar N-donor organic bases, have been prepared and studied by means of natural abundance C-13 and N-15 CP/MAS NMR spectroscopy. Useful correlations between molecular structures and C-13 and N-15 chemical shifts in these compounds have been established and assignments to carbon and nitrogen sites in resolved molecular structures have been suggested. A combination of the mesomeric effect of dithiocarbarnate groups and the (+)inductive effect of alkyl substituents at the nitrogen atoms has been discussed in interpretations of C-13 and N-15 chemical shifts of the studied compounds. A high sensitivity of N-15 chemical shift to the subtle structural differences of both dithiocarbarnate groups and N-donor molecules has been revealed. Several remarkable cases of conformational isomerism have been recognized for both dithiocarbamate complexes and their adducts.