title: Tetranuclear group 7/8 mixed-metal and open trinuclear group 7 metal carbonyl clusters bearing bridging 2-mercapto-1-methylimidazole ligands.
abstract: The reactivity of group 7 metal dinuclear carbonyl complexes [M(2)(CO)(6)(mu-SN(2)C(4)H(5))(2)] (1, M = Re; 2, M = Mn) toward group 8 metal trinuclear carbonyl clusters were examined. Reactions of 1 and 2 with [Os(3)(CO)(10)(NCMe)(2)] in refluxing benzene furnished the tetranuclear mixed-metal clusters [Os(3)Re(CO)(13)(mu(3)-SN(2)C(4)H(5))] (3) and [Os(3)Mn(CO)(13)(mu(3)-SN(2)C(4)H(5))] (4), respectively. Similar treatment of 1 and 2 with Ru(3)(CO)(12) yielded the ruthenium analogs [Ru(3)Re(CO)(13)(mu(3)-SN(2)C(4)H(5))] (5), and [Ru(3)Mn(CO)(13)(mu(3)-SN(2)C(4)H(5))] (6), but in the case of 2 a secondary product [Mn(3)(CO)(10)(mu-Cl)(mu(3)-SN(2)C(4)H(5))(2)] (7) was also formed. Compounds have a butterfly core of four metal atoms with the M (Mn or Re) at a wingtip of the butterfly and containing a noncrystallographic mirror plane of symmetry. This result provides a potential method for the synthesis of a series of new group 7/8 mixed metal complexes containing a bifunctional heterocyclic ligand. Compound 7 is a unique example of a 54-electron trimanganese complex having bridging 2-mercapto-1-methylimidazolate and chloride ligands. Interestingly, the reaction of 1 with Fe(3)(CO)(12) at 70-75 degrees C furnished the tri- and dirhenium complexes [Re(3)(CO)(10)(mu-H)(mu(3)-SN(2)C(4)H(5))(2)] (8) and [Re(2)(CO)(6)(N(2)C(4)H(5))(mu-SN(2)C(4)H(5))(2)] (9), respectively instead of the expected formation of the mixed-metal clusters. The former is an interesting example of a 52-electron trirhenium-hydridic complex containing bridging 2-mercapto-1-methylimidazolate ligand, while the latter can be viewed as a 1-methylimidazole adduct of 1 . No mixed Fe-Re complexes were produced in this reaction. The molecular structures of the new compounds and were established by single-crystal X-ray diffraction analyses and the DFT studies of compounds , and are reported.
authors.affiliation: Department of Chemistry, Jahangirnagar University, Savar, Dhaka, 1342, Bangladesh.
authors.forename: Shishir
authors.initials: S
authors.lastname: Ghosh
authors.forename: Shariff E
authors.initials: SE
authors.lastname: Kabir
authors.forename: Salina
authors.initials: S
authors.lastname: Pervin
authors.forename: Arun K
authors.initials: AK
authors.lastname: Raha
authors.forename: G M
authors.initials: GM
authors.lastname: Golzar Hossain
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Haworth
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Lindeman
authors.forename: Dennis W
authors.initials: DW
authors.lastname: Bennett
authors.forename: Tasneem A
authors.initials: TA
authors.lastname: Siddiquee
authors.forename: Luca
authors.initials: L
authors.lastname: Salassa
authors.forename: Herbert W
authors.initials: HW
authors.lastname: Roesky