Metallkomplexe mit Guanidinderivaten als Liganden: Kristallstrukturen von [Zn(cnge)2(SCN)2] · 2H2O und Zn(eoge)Br2 (enge = Cyanoguanidin; eoge = 1-Ethoxyiminomethylguanidin)

Abstract

Crystals of |Zn(cnge)2(SCN)2]-2H20 (1) were obtained by evaporation of an aqueous solution of Z n(S04)-7H20 , KSCN, and cyanoguanidine. Crystals of Zn(eoge)Br2 (2) were obtained by reaction of ZnBr-. and cyanoguanidine in ethanol/water. Both compounds are monoclinic, space group C2/c, 1: Z = 4, a = 1919.6(7), b = 467.3(2), c = 1838.5(6) pm, ß = 112.99(3)°, 2: Z = 8, a = 1799.5(6), b = 878.7(2), c = 1367.2(5) pm, ß = 101.52(3)°. In 1 each Zn is bonded to two cyanoguanidine molecules and via the N atoms to two NCS groups. Intermolecular hydrogen bonds lead to chains along the «-axis, and these chains are again connected via hydrogen bonds to the two crystal water molecules. In the course of the formation of 2, the cyanoguanidine reacted with the ethanol to form 1-ethoxyiminomethylguanidine. This ligand forms chelate rings with the Zn atoms, which are tetrahedrally coordinated by the two imino N atoms of the ligand and by two bromine atoms.