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.