Synthesis, Crystal Structures, and Properties of M(NCS)2‐3‐aminomethylpyridine Coordination Compounds (M = Cd, Zn)

Abstract

Reaction of Cd(NCS)2 or Zn(NCS)2 with 3‐aminomethylpyridine (3‐AMPy) leads to the formation of five compounds with the compositions [Cd(NCS)2(3‐AMPy)2·(3‐AMPy)]n (1‐Cd), [M(NCS)2(3‐AMPy)2]n [M = Cd (2‐Cd), Zn (2‐Zn)] [Cd(NCS)2(3‐AMPy)]n (3‐Cd), and [Zn(NCS)2(3‐AMPy)]2 (3‐Zn). In 1‐Cd the Cd cations are linked by the 3‐AMPy ligands into layers that consist of rings, built up of four Cd cations and four 3‐AMPy ligands. These layers are stacked to form channels, in which the 3‐AMPy solvate molecules are located. In the isotypic compounds 2‐Cd and 2‐Zn the metal cations are also linked into layers by the 3‐AMPy ligands with an identical layer topology as that in 1‐Cd, but a completely different conformation of the 3‐AMPy ligand. In the most 3‐AMPy deficient compound 3‐Cd, the Cd cations are linked by μ‐1,3‐bridging thiocyanate anions and 3‐AMPy ligands into chains, that are further connected into layers by additional anionic ligands. In 3‐Zn two Zn cations are linked by pairs of 3‐AMPy ligands into discrete dimers. Thermoanalysis and X‐ray powder diffraction (XRPD) investigations show that upon heating 1‐Cd transforms into 2‐Cd and 2‐Zn into 3‐Zn. The compounds 2‐Cd, 3‐Cd, 2‐Zn, and 3‐Zn present ligand‐based luminescence in the blue‐green spectral range with maxima between 21276 and 21795 cm–1.