Mercury-Bridged Cobaltacarborane Complexes Containing B-Hg-B Three-Center Bonds. Synthesis and Structure of mu, mu'-((n5-C5R5)Co(CH3)2C2B3H4)Hg, mu-(n(5)-C5R5)Co(CH3)2C2B3H4)HgCl, (R=H, CH3) and Related Compounds.
Abstract
Reactions of the nido-cobaltacarborane anions (eta 5-C5H5)Co(CH3)2C2B3H4- and (eta 5-C5(CH3)5)Co(CH3)2C2B3H4(-) with HgCl2 in tetrahydrofuran give initially the unstable adduct ((eta5-C5R5)Co(CH3)2C2B3H4.HgCl2)(-) (R = H, CH3), which lose Cl- to form the isolable HgCl-bridged complexes mu-(eta 5-C5R5)Co(CH3)2C2B3H4)HgC1; the latter species undergo symmetrization to generate the bis(cobaltacarboranyl)mercury complexes mu,mu'-(eta 5-C5R5)Co(CH3)2C2B3H4)2Hg. In the cyclopentadienyl system (R = H), the formation of the mu,mu' complex is rapid, giving high yields within minutes; in contrast, the pentamethylcyclopentadienyl species reacts much more slowly, requiring days to form the mu,mu' complex in isolable quantity. Thus, the characterization of the mono (cobaltacarboranyl)mercury complex is readily achieved with the C5(CH3)5-substituted cobaltacarborane. The structural characterization of the Hg-bridged complexes is based on pulse Fourier transform 1H and 11B NMR, ir, and mass spectra, and single-crystal X-ray diffraction studies of mu-(eta 5-C5(CH3)5)Co(CH3)2C2B3H4-HgC1 and mu,mu'-((eta-C5H5)Co(CH3)2C2B3H4)2Hg. The mono(cobaltacarboranyl) complex crystallizes as a dimer with weak intermolecular Hg...Cl interactions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1980
- Accession Number
- ADA092270
Entities
People
- David C. Finster
- Russell N. Grimes
Organizations
- University of Virginia