Preparation of Monocarbon Polymetallocarboranes and the Crystal and Molecular Structure of a Novel Electron-Rich Nido-Trimetallocarborane,
Abstract
Reaction of nido-3-R-2-CB5H8 (R=H or CH3) with nickelocene and sodium amalgam has yielded the first trimetallocarboranes containing nickel, (C5H5Ni)3CB5H5R, isolated in several isomeric forms. The complexes are formulated as formal mixed-valence Ni(III)-Ni(III)-Ni(IV) systems; the near infrared spectra support this formulation and indicate substantial mixed-valence charge transfer. Reaction of closo-1-CB9H10(-) with cobaltocene and sodium amalgam produced the closo-icosahedral bimetallic species (C5H5Co)2CB9H10(-) containing a metal-metal bond. The crystal structure of one isomer of (C5H5Ni)3CB5H6 was determined from three-dimensional X-ray counter data. The complex crystallizes in the orthorhombic system, space group Pbnm (alternate setting of Pnma) with a=7.518(1) A, b = 14.740(2) A, c = 15.711(3) A and Z = 4. The electron-rich trimetallocarborane was found to adopt a novel nido geometry best described as a distorted monocapped square antiprism. Three nickel atoms and a boron atom compose the four-membered open face; the two equivalent nickel-nickel distances are 2.404(1) A. Non-bonded distances in the open face are Ni-Ni = 3.250(1) A and Ni-B - 2.991(5) A. The geometry is discussed in relation to electron counting rules for polyhedral heteroboranes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 04, 1976
- Accession Number
- ADA028638
Entities
People
- Charles E. Strouse
- Chris G. Salentine
- M. Frederick Hawthorne
Organizations
- University of California, Los Angeles