Adducts of zinc and copper(II) dimethyland diethyldithiocarbamates with piperidine: Synthesis, EPR, solid-state natural abundance 13C and 15N CP/MAS NMR and single-crystal X-ray diffraction studies

Crystalline adducts of zinc and copper(II) dimethyl-and diethyldithiocarbamates with piperidine (Pip) of the general formula [M{NH(CH₂)₅}(S₂CNR₂)₂] (M = Zn and ⁶³Cu; R = CH₃ and C₂H₅) were obtained. Their structures and spectroscopic characteristics were studied by X-ray diffraction analysis, EPR spectroscopy, and solid-state natural abundance ¹³C and ¹⁵N MAS NMR spectroscopy. The most substantial differences between the adducts of the formula [Zn{NH(CH₂)₅}(S₂CNR₂)₂] (R = CH₃ and C₂H₅) were found in the spatial orientations of the coordinated heterocycles and the geometries of the zinc polyhedra. The individual character of the EPR spectra of magnetically diluted isotope-substituted copper(II) adducts was determined by computerassisted modeling. The adducts of copper(II) and zinc dimethyldithiocarbamates proved to exist as two isomers. The coordination polyhedra of copper(II) and zinc are intermediate between a tetragonal pyramid (TP) and a trigonal bipyramid (TBP). The contributions from the TBP/TP components to the coordination polyhedra were quantitatively estimated from X-ray diffraction data. The ¹³C and ¹⁵N NMR signals were assigned to the positions of the atoms of the =NC(S)S^? groups in the resolved (according to X-ray diffraction data) molecular structures of the adducts.