Synthesis and Characterization of Anionic Halogen-Containing Rhodacarboranes. The Crystal and Molecular Structure of the Hydrogen Bonded Ion Pair, (HPPh3) (closo-3-(Ph3P)-3,3-(Br)2-3,1,2-RhC2B9H11).
CALIFORNIA UNIV LOS ANGELES DEPT OF CHEMISTRY
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We recently reported the reaction of closo-3,3-Ph3P2-3-H-3,1,2-RhC2B9H11, 1, with benzoyl peroxide which afforded the asymmetric phosphinorhoadcarborane dimer closo-Ph3PRhC2B9H112, 2, in modest yields ca 40.2 In order to conduct a more thorough study of the chemical reactivity and catalytic properties of this dimeric complex we sought a more efficient conversion of 1 to 2 employing Lewis acids. While the reactions of 1 with diborane and boron trifluoride did indeed proceed as that with boron tribromide produced a bromine-containing phosphinorhodacarborane in low yield which was shown by X-ray crystallography to be the ionic complex HPPh3closo-3-Ph3P-3,3-Br2-3,1,2-RhC2B9H11, HPPh33. Subsequent to the characterization of HPPh3 3 improved synthetic methods were developed which allowed the isolation of 3- with a variety of supporting counterions in good yields. Moreover, it was found that the iodo and chloro analogs of 3- could be easily prepared. Herein we report the details of these studies.
- Organic Chemistry
- Atomic and Molecular Physics and Spectroscopy
- Nuclear Physics and Elementary Particle Physics