title: Mixed-metal chalcogenide tetrahedral clusters with an exo-polyhedral metal fragment.
abstract: The reaction of metal carbonyl compounds with group 6 and 8 metallaboranes led us to report the synthesis and structural characterization of several novel mixed-metal chalcogenide tetrahedral clusters. Thermolysis of arachno-[(Cp*RuCO)2B2H6], 1, and [Os3(CO)12] in the presence of 2-methylthiophene yielded [Cp*Ru(CO)2(μ-H){Os3(CO)9}S], 3, and [Cp*Ru(μ-H){Os3(CO)11}], 4. In a similar fashion, the reaction of [(Cp*Mo)2B5H9], 2, with [Ru3(CO)12] and 2-methylthiophene yielded [Cp*Ru(CO)2(μ-H){Ru3(CO)9}S], 5, and conjuncto-[(Cp*Mo)2B5H8(μ-H){Ru3(CO)9}S], 6. Both compounds 3 and 5 can be described as 50-cve (cluster valence electron) mixed-metal chalcogenide clusters, in which a sulfur atom replaces one of the vertices of the tetrahedral core. Compounds 3 and 5 possess a [M3S] tetrahedral core, in which the sulfur is attached to an exo-metal fragment, unique in the [M3S] metal chalcogenide tetrahedral arrangements. All the compounds have been characterized by mass spectrometry, IR, and (1)H, (11)B and (13)C NMR spectroscopy in solution, and the solid state structures were unequivocally established by crystallographic analysis of compounds 3, 5 and 6.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India. sghosh@iitm.ac.in.
authors.forename: K
authors.initials: K
authors.lastname: Yuvaraj
authors.forename: Dipak Kumar
authors.initials: DK
authors.lastname: Roy
authors.forename: V P
authors.initials: VP
authors.lastname: Anju
authors.forename: Bijnaneswar
authors.initials: B
authors.lastname: Mondal
authors.forename: Babu
authors.initials: B
authors.lastname: Varghese
authors.forename: Sundargopal
authors.initials: S
authors.lastname: Ghosh