REACTIONS OF COORDINATED MOLECULES .18. COMPLEXES OF THE TRIACYLMETALATE DIANIONS

Triacylmetalate dianions of the type [fac-(OC)3Re(CH3CO)2(RCO)]2-, where R is methyl, isopropyl, benzyl, or the bridging ligands (CH2)n where n is 5 or 6, are prepared from the corresponding neutral acylpentacarbonylrhenium complexes and 2 equiv of methyllithium. The formation of these anions is followed by IR, and the triacetyl dianion is isolated as the PPN salt. These dianions form bis-chelate complexes with Al(III), Ga(III), Hf(IV), and Zr(IV) metal ions. The aluminum and gallium complexes are anionic while the hafnium and zirconium complexes are neutral. The ligands act as tridentate chelates possessing idealized C3v symmetry. This coordination geometry is confirmed by the observation of geometrical isomers for those complexes having unsymmetrically substituted ligands. © 1979, American Chemical Society. All rights reserved.