METALLOBORANES .I. METAL COMPLEXES OF B3 B9 B9S B10 AND B11 BORANE ANIONS

Triborohydride ion (B3Hs−) reacts with metal hexacarbonyls to give M(CO)4B3H8− with M = Cr, Mo, W. Isolated as crystalline salts, these anions are yellow and air stable. The triborohydride moiety is attached to the metal atom in these complexes by means of two adjacent M-H-B three-center bonds as shown by the crystal structure analysis of a Cr(CO)4- B3H8− salt. An identical mode of structural attachment is proposed for the complexes of [(C6H5)P]2M′B3H8 (M′ = Cu, Ag) and (C5H5)TiB3H8. The fragment anions B9H14− and B9H12S− form a series of colorless tristriphenylphosphine complexes of copper, silver, and gold which appear to be simple salts in the solid state and in highly polar media. X-Ray studies of the gold derivative show a trigonal P3Au+ cation and a B9H12S− anion with the predicted B9S skeleton (B10H142− analog). In solution, particularly nonpolar media, there appears to be a significant interaction between the cation and the anion as evidenced by the perturbation of the characteristic B9H14− and B9H12S− B11 nmr spectra. Analogous metal complexes derived from B10H13− show varied behavior and in some of these, particularly the copper derivative, there may be metal- borane interactions. The properties of copper and gold phosphine derivatives of B11H14− are consonant with simple salts of B11H14−. © 1968, American Chemical Society. All rights reserved.