THE AZAMACROCYCLIC DERIVATIVES OF H4RU4(CO)(12) AND THEIR REACTIVITY WITH CO AND CATALYTIC ACTIVITY IN THE METHANOL CARBONYLATION AND IN THE WATER-GAS SHIFT REACTION

The reactions of H4Ru4(CO)(12) with cyclic triazaligands result in the formation of [LH](+)[H3Ru4(CO)(12)](-) salts, (L = 1,4,7-triazacyclon onane (1), 1,4,7-trimethyl-1,4,7-triaza-cyclononane (2), 1,5,9-triazac yclododecane (3) and 1,5,9-trimethyl-1,5,9-triazacyclododecane (4)). T he compounds were synthesized by refluxing H4Ru4(CO)(12) in hexane fol lowed by precipitation with the corresponding ligand. This is a conven ient direct single-step synthetic route to produce [H3Ru4(CO)(12)](-)- ion with a high yield. The compounds have been characterized by elemen tal analysis and spectroscopic measurements. In the H-1 NMR spectra th ey showed a fluxional behavior. Reactivity towards CO at elevated temp erature, and the catalytic activity of the new compounds in the water- gas shift reaction (WGSR) and in the carbonylation of methanol, have b een discussed. (C) 1997 Elsevier Science S.A.