Synthesis of new fluoro derivatives of o-carborane [3-F-7,8-C2B9H11]-, 3,6-F2-1,2-C2B10H10, and [6,6′-F2-3,3′-Co(1,2-C2B9H10)2]-

The 3,6-difluoro derivative of ortho-carborane 3,6-F-2-1,2-C2B10H10 was obtained by a triple sequence of deboronation and BF-insertion reactions. 3-Fluoro and, especially, 3,6-difluoro derivatives of ortho-carborane were found to have an increased propensity to deboronation with elimination of the BF group under the action of even weak nucleophilic agents, which, apparently, is explained by a reduced electron density on the boron atoms bearing fluorine atoms. The 6,6 '-difluoro derivative of cobalt bis(dicarbollide) [6,6 '-F-2-3,3 '-Co(1,2-C2B9H10)(2)](-) was obtained from 3-fluoro-nido-carborane [3-F-7,8-C2B9H11](-). The new fluoro derivatives of ortho-carborane were characterized by multinuclear NMR spectroscopy.