Syntheses and crystal structures of bis-(4-methyl-pyridine-κ)bis-(seleno-cyanato-κ)zinc(II) and -poly[[bis-(4-methyl-pyridine-κ)cadmium(II)]-di-μ-seleno-cyanato-κ :;κ :].

The reactions of Zn(NO) 6HO and Cd(NO) 4HO with KSeCN and 4-meth-yl-pyridine (CHN; 4-picoline) lead to the formation of crystals of bis-(4-methyl-pyridine-κ)bis-(seleno-cyanato-κ)zinc(II), [Cd(NCSe)(CHN)] (), and -poly[[bis-(4-methyl-pyridine-κ)cadmium(II)]-di-μ-seleno-cyanato-κ :;κ :], [Cd(NCSe)(CHN)] (), suitable for single-crystal X-ray diffraction. The asymmetric unit of compound consists of one Zn cation that is located on a twofold rotation axis as well as one seleno-cyanate anion and one 4-methyl-pyridine ligand in general positions. The Zn cations are tetra-hedrally coordinated by two terminal N-bonding thio-cyanate anions and two 4-methyl-pyridine ligands, forming discrete complexes. The asymmetric unit of compound consists of two crystallographically independent Cd cations, of which one is located on a twofold rotation axis and the second on a center of inversion, as well as two crystallographically independent seleno-cyanate anions and two crystallographically independent 4-methyl-pyridine ligands in general positions. The Cd cations are octa-hedrally coordinated by two N- and two S-bonding seleno-cyanate anions and two 4-methyl-pyridine ligands and are linked into chains by pairs of seleno-cyanate anions. Within the chains, the Cd cations show an alternating -- and - coordination and therefore, the chains are corrugated. PXRD investigations prove that the Zn compound was obtained as a pure phase and that the Cd compound contains a very small amount of an additional and unknown phase. In the IR spectrum of , the CN stretching vibration of the seleno-cyanate anion is observed at 2072 cm, whereas in the it is shifted to 2094 cm, in agreement with the crystal structures.