SYNTHESIS AND STRUCTURES OF BENZO-TETRACA RBAHEXABORANE AND 1,3-DIHYDRO-1,3-DIBORANAPHTHALENE METAL-COMPLEXES

The benzo-tetracarbahexaborane derivative 1 reacts with pentamethylcyc lopentadienylcobalt-bisethene, cyclopentadienylrhodium-bisethene and t ricarbonyliron-biscyclooctene to yield the cobalt, rhodium, and iron c omplexes 5, 6, and 7, in which the metal is bound eta(4) to the benzo ring. In contrast the reactions of 1 with cyclopentadienylcobalt-biset hene and cyclopentadienyliron-cyclooctadiene form the 1,3-dihydro-1,3- diboranaphthalenecobalt complexes 8, 9 and the iron-iron triple-decker complex 10. The constitutions of the complexes 5-10 are derived from spectroscopic data and are confirmed by X-ray structure analyses for 5 , 7, 8 and 10.