title: Reactions of a methylmercury zwitterionic thiolate complex [MeHg(Tab)]PF6 with various donor ligands: relevance to methylmercury detoxification.
abstract: Reaction of MeHgI with Ag(2)O in H(2)O followed by addition of equimolar TabHPF(6) in MeCN gave rise to a methylmercury zwitterionic thiolate complex [MeHg(Tab)]PF(6) (1) (TabH = 4-(trimethylammonio)benzenethiol) in a high yield. Treatment of 1 with KI and KSCN afforded an anion exchange product [MeHg(Tab)]I·0.25H(2)O (2·0.25H(2)O) and [MeHg(Tab)]SCN (3), respectively, while that of 1 with equimolar Tab resulted in the formation of another MeHg/Tab compound [MeHg(Tab)(2)]PF(6) (4). The cation of 2 or 3 shows an approximately linear structure in which the central Hg(II) is coordinated by one C atom of one CH(3) group and one S atom of a Tab ligand. The Hg(ii) center of the cation of 4 is trigonally coordinated by one C atom of the CH(3) group and two S atoms of two Tab ligands. The analogous reaction of 1 with NH(4)SCN led to the cleavage of the Hg-C bond of 1 and the formation of a known four-coordinated Hg(II)/Tab complex [Hg(Tab)(2)(SCN)(2)] (5). When 4 was treated with 4,6-Me(2)pymSH or EtSH, another four-coordinated Hg(II)/Tab complex [Hg(Tab)(4)](3)(PF(6))(6) (6) was generated in a high yield. The Hg(II) center of each cation of 6 is tetrahedrally coordinated by four S atoms of four Tab ligands. The results suggested that cleavage of the Hg-C bond in the methylmercury complex 1 could be completed by increasing the coordination number of its Hg(II) center by S-donor ligands and protonating the methyl group by weak acids.
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, P R China.
authors.forename: Ai-Xia
authors.initials: AX
authors.lastname: Zheng
authors.forename: Hong-Xi
authors.initials: HX
authors.lastname: Li
authors.forename: Kai-Peng
authors.initials: KP
authors.lastname: Hou
authors.forename: Jing
authors.initials: J
authors.lastname: Shi
authors.forename: Hui-Fang
authors.initials: HF
authors.lastname: Wang
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Ren
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Lang
mesh_terms: D018360:Crystallography, X-Ray; D008024:Ligands; D009941:Organomercury Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D008024:Ligands; D009941:Organomercury Compounds; D013438:Sulfhydryl Compounds