Synthesis, characterisation and study of mercury(II) chloride complexes with triphenylphosphine and heterocyclic thiones. The crystal structures of [(benzothiazole-2-thionato)-(benzothiazole-2-thione)(bis-triphenylphosphine)chloro mercury(II)] and [(mu(2)-dichloro) {(bis-pyrimidine-2-thionato)-mercury(II)} {(bis-triphenylphosphine)mercury(II)}] at 100 K

Direct reaction of mercury(II) chloride with triphenylphosphine (PPh3) and benzothiazole-2-thione (bzthtH) in the molar ratio of 1:1:2 results in the formation of the [Hg(PPh3)(bzthztH)(bzthzt)Cl] (1) (bzthzt = the anion of b enzothiazole-2-thione) while the reaction of mercury(II) chloride with trip henylphosphine (PPh3) and pyrimidine-2-thione (pmtH) in the molar ratio of 1:1:1 gives [Hg2Cl2(PPh3)(2)(pmt)(2)] (2) (pmt = the anion of pyrimidine-2- thione). The complexes have been characterised by their elemental analyses, melting points and their FTIR, far-IR spectroscopic data. The crystal stru cture of complex 1 which has: been determined by single-crystal X-ray cryst allography at r.t. reveals that the molecule is monomeric with tetrahedral geometry around the metal ion. A benzothiazole-2-thione molecule and a benz othiazole-2-thionato anion are coordinated, via sulfur atoms, to the mercur y(II) ion [Hg-S(ZA)= 2.726(2) and Hg-S(2)= 2.419(2) Angstrom]. A triphenylp hosphine molecule is also coordinated through a phosphorus atom to the meta l ion [Hg-P = 2.453(2) Angstrom] while the tetrahedral geometry around the mercury is completed by a chlorine atom [Hg-Cl= 2.633(2) Angstrom]. The com plex is covalent in the solid state. The crystal structure of complex 2 whi ch has also been established by single-crystal X-ray crystallography at 100 (1) K shows that the molecule is binuclear and consists of two different mo ieties with tetrahedral geometry around each mercury(II) ion. One moiety co nsists of a mercury(II) ion with two phosphorus atoms from phosphine ligand s and two bridging chlorine atoms, while the other consists of a mercury(II ) ion and two sulfur atoms of pyrimidine-2-thionato ligands. The entire com plex is covalent in the solid state. The two Hg(2)S(42) bond lengths are 2. 3513(11) Angstrom while the two Hg(1)-P(1) bond lengths are 2.4826(9) Angst rom. The: two parts of the molecule are linked to each other by two chlorin e atoms with Hg(1)Cl(1) and Hg(Z)-Cl(1) bond distances of 3.5310(10) and 3. 0372(10) Angstrom, respectively. (C) 2000 Elsevier Science B.V. All rights reserved.