Mercury(II) cyanide complexes of thioureas and the crystal structure of [(N-methylthiourea)2 Hg(CN)2

Abstract

Mercury(II) cyanide complexes of thioureas (Tu), N-methylthiourea (MeTu), and N,N′-dimethylthiourea (DmTu)) have been prepared and characterized by IR and NMR (1H and 13C) spectroscopy, and the crystal structure of one of them was determined by X-ray crystallography. An upfield shift in 13C NMR and downfield shifts in 1H NMR are consistent with the sulfur coordination to mercury(II). The appearance of a band around 2200 cm−1 in IR and a resonance around 145 ppm in 13C NMR indicates the binding of cyanide to mercury(II). The NMR data show that the [(Thione)2Hg(CN)2] complexes are stable in solution and undergo no redistribution reactions. In the crystal structure of the title complex, mercury atom is coordinated to two thione sulfur atoms of MeTu and to two cyanide carbon atoms in a distorted tetrahedral mode with the bond angles in the range of 90.2(2)°–169.3(3)°.