Direct Insertion of Transition Metals into Polyhedral Carboranes. Structurally Novel Mono-,Di-,and Trimetallic Small Cage Systems.

摘要

Metallocarboranes of iron,cobalt and nickel have been prepared by the direct reaction of the small polyhedral carboranes 1,5-C2B3H5, 1,6-C2B4H6,or 2,4-C2B5H7with organometallic and metal carbonyl reagents in the gas phase or in solution,without the use of a prior cage-opening step. Novel 6-vertex cages as well as 7-vertex species were obtained,including mono-,di-,and trimetallocarborane species. Molecular structures were assigned to the new compounds on the basis of boron-11and proton nmr spectra. Fine structure in the carborane CH proton nmr signals exhibited by several of the cobaltacarborane species was interpreted on the basis of H-C-B-H proton-proton coupling. (Modified author abstract)