Crystal structures of [Hg(N-ethylthiourea)2(CN)2] and [Hg(N-propylthiourea)2(CN)2]

Abstract

Two mercury(II) cyanide complexes of N-ethylthiourea (Ettu) and N-propylthiourea (Prtu) ligands, [Hg(Ettu) 2 (CN) 2 ] (1) and [Hg(Prtu) 2 (CN) 2 ] (2), were prepared and their crystal structures were determined by X-ray crystallography. In both structures, the mercury atom is coordinated to two sulfur atoms of thioureas and two cyanide carbon atoms in a pseudo-tetrahedral mode with the bond angles in the range of 90.52(11)-162.2(3)°. The structures are stabilized by N-H---S, N-H---N, and C-H---N intramolecular and intermolecular hydrogen bonds. Crystallographic reports about mercury(II) complexes containing thioamides establish that these ligands are coordinated via the sulfur atom [1-26]. The crystal structures of the 1:2 complexes usually consist of discrete monomeric molecules [1-20], while those of 1:1 often involve dimeric species [20-26]. However, in both types of complexes, mercury(II) exhibits a tetrahedral or pseudo-tetrahedral coordination environment. We have recently reported the crystal structures of Hg(CN) 2 complexes of methylthiourea (Metu) [7], N,N′-diethylthiourea (Dintu) [8], N,N′-dibutylthiourea (Dbtu) [9], and tetramethylthiourea (Tmtu) [27]. Although the structures of other thiourea complexes are usually of the type L 2 HgX 2 [7-9], the Tmtu complex, [{(tetramethylthiourea) 2 Hg(CN) 2 } 2 ⋅Hg(CN) 2 ] is trinuclear consisting of two independent [(Tmtu) 2 Hg(CN) 2 ] moieties bridged by a Hg(CN) 2 unit [27]. In order to investigate further about the structures of mercury cyanide complexes, we report here the crystal structures of two monomeric Hg(CN) 2 complexes: bis(cyanido)bis(Nethylthiourea-κS)mercury(II), [Hg(Ettu) 2 (CN) 2 ] (1) and bis(cyanido)bis(N-propylthiourea-κS)mercury(II), [Hg(Prtu) 2 (CN) 2 ](2), which are characterized by extensive hydrogen bonding.

Dinuclear and polymeric Hg(II) complexes with 1-(2-furoyl)thiourea derivatives: Their crystal structure and related properties

“…Nevertheless, in both types of complexes, mercury(II) exhibits a tetrahedral distorted geometry [13,29,[30][31][32][33].…”