Reactions of the polyhydride complex ReH7(PPh3)2 with pyridinecarboxylic acids, 2-hydroxypyridine, 2-hydroxy-6-methylpyridine, and acetylacetone. Monohydrido complexes of rhenium(III) and their oxidation to the corresponding rhenium(IV) derivatives

Abstract

The rhenium polyhydride complex ReH 7 (PPh 3 ) 2 reacts with various organic acids to give neutral monohydrido rhenium(III) complexes of stoichiometry ReH(L) 2 (PPh 3 ) 2 , where L represents the monoanion of pyridine-2-carboxylic acid (pic), 1-isoquinolinecarboxylic acid, pyridine-2,3-dicarboxylic acid, 2-hydroxypyridine, 2-hydroxy-6-methylpyridine, and acetylacetone (acac). These complexes display a reversible couple in their cyclic voltammograms which is associated with a one-electron oxidation to their 17-electron cations. The complexes [ReH(pic) 2 (PPh 3 ) 2 ]PF 6 , ReH(acac) 2 (PPh 3 ) 2 , and [ReH(acac) 2 (PPh 3 ) 2 ]PF 6 have been structurally characterized by X-ray crystallography