Self-assembly of mercaptane-metallacarborane complexes by an unconventional cooperative effect: A C-H⋯S-H⋯H-B hydrogen/dihydrogen bond interaction

The existence of a dihydrogen bond (S-H⋯H-B) and its combination with a C-H⋯S hydrogen bond in an unusual cooperative effect are demonstrated from a combination of experimental and theoretical methods. This cooperative effect seems to be responsible for self-assembly of mercaptane-metallacarborane complexes such as closo[3-Ru(η6- C6H6)-8-HS-1,2-C2B9H10] (1) and closo[3-Co(η5-C5H5)-8-HS-1,2-C 2B9H10] (3), which present identical supramolecular two-dimensional polymeric networks. The findings, besides documenting structurally the first S-H⋯(H-B)2 dihydrogen bond and the unconventional cooperative ability of a boron-attached SH group, prove that substituted carboranes have the potential to serve as building blocks for assembling complex structures. © 2005 American Chemical Society.