Base-Free Dehydrogenation of Aqueous and Neat Formic Acid with Iridium(III) Cp*(dipyridylamine) Catalysts

The selective dehydrogenation of formic acid by iridium(III) Cp*(dipyridylamine) catalysts is reported. The electron-enriched catalyst [(IrCp)-Cp-III*{(4-dimethylaminopyridin-2-yl-kappa N)(pyridin-2 '-yl-kappa N)amine}(OSO3)] gave the best performances enabling the base free dehydrogenation of aqueous and neat formic acid. In both cases the reaction was selective with no carbon monoxide detectable. The Ir-III complex demonstrated latent behavior, which may be of practical utility. Experimental results suggest an outer-sphere interaction with the ligand.