Synthetic, structural, and spectroscopic studies of the ligating properties of organic disulphides: X-ray structures of mercury(II) chloride–dimethyl disulphide (1/1) and triethylammonium trichloromercurate

Abstract

The synthesis of a series of complexes of mercury(II) halides with dimethyl and diethyl disulphide has been attempted, but of the products thereby formed, only HgCl₂·Me₂S₂(1) was sufficiently stable to be characterised by an X-ray crystallographic structure determination. Complex (1) crystallizes in the monoclinic space group C2/c, with cell dimensions (at 20 °C)a= 14.865(4), b= 9.185(1), c= 12.441(3)Å, = 109.23(1)°, and Z= 8. The structure was solved by the heavyatom method, and refined to R 0.043 (R′ 0.044) for 1 118 observed reflections. The structure consists of –Hg–Cl–Hg–Cl– chains, with the disulphide molecule loosely and asymmetrically co-ordinated in a bridging mode between adjacent pairs of mercury atoms. When using commercial Me₂S₂(without further purification) a crystalline by-product, [NHEt₃][HgCl₃](2), was unexpectediy obtained, and its structure determination was carried out to confirm its identity. Crystals of (2) are monoclinic, space group P2₁/n, with cell dimensions (at 20 °C)a= 7.639(2), b= 14.711(1), c= 11.074(3)Å, β= 100.28(1)°, and Z= 4. The structure was refined to R 0.046 (R′ 0.033) for 1 074 observed reflections. The origin of complex (2) from the ‘HgCl₂–Me₂S₂’ reaction is discussed.