Rotation isomers of bis(diethyldithiocarbamato)zinc(II) adduct with pyridine, Zn(EDtc) 2·Py: ESR, 13C and 15N CP/MAS NMR and single-crystal X-ray diffraction studies

Abstract

The adduct of bis(diethyldithiocarbamato)zinc(II) with pyridine, Zn(EDtc) 2·Py, was prepared and studied by means of ESR ( 63Cu 2+ and 65Cu 2+ were used as spin labels), solid-state natural abundance 13C and 15N CP/MAS NMR spectroscopy and single-crystal X-ray diffraction data analysis. Two rotation isomers of the adduct were unambiguously determined by these three independent methods. It was found that these two isomers have different orientations of the pyridine ring about the N(Py)–Zn axis. The acute angles of the plane of the pyridine molecules relative to the most weak Zn–S bond are equal to 45.6 and 52.7° in the different isomers. Adduct molecules adopt a geometry which is intermediate between the square pyramidal (C 4v) and the trigonal bipyramidal (D 3h). All ESR and NMR resonances of Zn(EDtc) 2·Py were assigned.