Synthesis, Structures, and Physical Properties of Thiocyanate Coordination Compounds with 3-Hydroxymethylpyridine

Abstract

The reaction of Cd(NCS)2 with 3-hydroxymethylpyridine (3-HMPy) leads to the formation of compounds with the composition Cd(NCS)2(3-HMPy)4 (1-Cd), Cd(NCS)2(3-HMPy)2 (2-Cd) (Cd(NCS)2)2(3-HMPy)3 (3-Cd), and (Cd(NCS)2)3(3-HMPy)4 (4-Cd). Compound 1-Cd consists of discrete complexes and in 2-Cd the Cd cations are linked into chains by the anionic and the organic co-ligands. In 3-Cd as well as 4-Cd the Cd cations are connected into chains by the thiocyanate anions, which are further linked into layers by the 3-HMPy co-ligands. In contrast, with Zn only one compound with the composition Zn(NCS)2(3-HMPy)2·H2O (1-Zn-H2O) was characterized by single-crystal X-ray diffraction, which shows a tetrahedral coordination of the Zn cations by two thiocyanate anions and two 3-HMPy ligands. The discrete complexes are arranged to form channels, in which the water molecules are embedded. 1-Zn-H2O cannot be obtained phase pure and detailed investigations reveal, that additional Zn compounds with the composition Zn(NCS)2(3-HMPy)2·xH2O including an anhydrate (1-Zn) can be obtained, which possesses a similar X-ray powder diffraction (XRPD) pattern. 1-Zn was characterized using X-ray powder diffraction analysis. Most compounds were investigated by thermoanalysis, IR and Raman as well as luminescence spectroscopy.