Preparation of complexes of the 3-trimethylammonio-1-propanethiolato ligand, [M{S(ÇH<inf>2</inf>)<inf>3</inf>NMe<inf>3</inf>}<inf>2</inf>](PF<inf>6</inf>)<inf>2</inf>, M=Zn, Cd, Hg. Crystal structures of monomeric and polymeric forms of the mercury complex

Reaction of metal acetates with 3-trimethylammonio-1-propanethiol hexafluorophosphate [HS(CH2)3NMe3](PF6) in a methanol-acetonitrile-aqueous sodium hydroxide solution gives complexes of formula [M{S(CH2)3NMe3}2](PF6)2 (M=Zn, Cd, Hg) as crystalline or microcrystalline solids. In the case of mercury, an alternative product, [M{S(CH2)3NMe3}2](PF6)2· 1 2[S(CH2)3NMe3] is sometimes obtained instead, from an apparently identical procedure. The crystal structures of both mercury complexes have been determined. [Hg{S(CH2)3NMe3}2](PF6)2· 1 2[S(CH2)3NMe3] contains polymeric chains of mercury atoms bridged by pairs of aminothiolato ligands to give tetrahedral coordination with Hg-S 2.564(3) and 2.567(3) Å. The cation chains run parallel to the tetragonal unit cell c axis and are separated by PF6- anions. Channels in the structure are probably occupied by the disordered additional ligand molecules in zwitterionic form. [Hg{S(CH2)3NMe3}2](PF6)2 contains essentially linear mononuclear cations with Hg-S 2.321(9)-2.370(11) Å, which are linked by weaker Hg...S interactions (2.98-3.59 Å) into loose octameric cation units. These are widely separated from each other by the surrounding anions. © 1991.