Impact of Coordinated Pseudohalide Ions and Picolinamide on Supramolecular Synthons in Selected Zinc and Cadmium Complexes.

Four new Zn(II) and Cd(II) picolinamide (pia) complexes with cyanate and azide, e.g. [Zn(OCN)2(pia)2] (1), [Cd(OCN)2(pia)2]n (2), [Zn(N3)2(pia)2] (3) and [Cd(N3)2(pia)2]n·nH2O (4), have been prepared and characterized by IR and NMR spectroscopy, and thermal (TG/DTA) methods. For the compounds 1 and 3 X-ray analysis revealed mononuclear molecular structure with octahedral N4O2 environment around the zinc(II) center with cis-arrangement of ligands. Only in 1 the amide head-to-head supramolecular motifs, represented by an R2(2) (8) designator, are observed, while in 3 none of the typical amide motifs were found. While the IR data suggests the polymeric structures for 2 and 4 in the solid state, all the NMR spectra agree with the monomeric structure of the compounds in the solution.