Organotransition-Metal Metallacarboranes. 5. Studies on (eta 6-Arene)(Carborane)Iron Complexes of Benzene and Biphenyl. Crystal Structures of (eta 6-C6H5-C6H5)Fe(Et2C2B4H4) and 1,2-((eta 6-C6H6)Fe(Et2C2B4H3))2CH(CH3)CH2, a Hydroca

摘要

Transition-metal sandwich complexes in which one ligand is an arene or other aromatic system (e.g., C8H8(2-)3 and the other is a carborane or borane form a bridge between two well-established areas of organometallic chemistry. These two families-metal-arene sandwiches and metallacarboranes/metallaboranes-have both found application in synthesis, but their chemistry is quite different. Hence it is worthwhile to explore the possibilities for creating novel synthetic reagents which combine the characteristics of metal-arene and metal-boron systems. Of even greater potential interest would be complexes manifesting new chemistry not reflective either parent class. Earlier papers in this series have described the synthesis and structural characterization of several (Eta superscript 6 arene)Fe(Et2C2B4H4) complexes via ligand exchange with the very useful precursor (Eta superscript 6-C8H10)Fe(Et2C2B4H4)(1a,2d,e,3a). Recently, we have begun to examine the reactivity of these species with respect to 1) the hydrocarbon ligand, 2) the carborane cage, and 3) the metal center. This paper reports some chemistry of (Eta superscript-6-C6R6)Fe(Et2C2B4H4) complexes involving stepwise transformations of the carborane cage, as well as the preparation, structure, and metal complexation of an (Eta superscript-6-biphenyl)ferracarborane.