Triphenylphosphine-substituted N,N-di-iso-propylcarbamate of ruthenium(II) and its reactions with carbon monoxide

Chloride displacement from RuCl2(PPh3)3 by NHiPr2/CO2 in toluene as medium gave the N,N-di-iso-propylcarbamato derivative Ru(O2CNiPr2)2(PPh3)2, (1), whose X-ray crystal structure determination showed the mononuclear compound to contain hexacoordinated ruthenium bonded to bidentate carbamato and to cis-arranged tertiary phosphine groups in a distorted octahedral geometry. Carbonylation at room temperature rapidly converted 1 to the monocarbonyl derivative Ru(O2CNiPr2)2(PPh3)2(CO) (2), presumably containing a monodentate carbamato group, the dicarbonyl compound Ru(O2CNiPr2)2(PPh3)2(CO)2 (3) being formed over longer reaction times. X-ray diffraction data showed 3 to contain hexacoordinate ruthenium(II) with monodentate carbamato groups trans to the carbonyl groups and with trans-arranged triphenylphosphine groups. Controlled hydrolysis of 3 yielded the dicarbonyl-carbonato complex Ru(O3C)(PPh3)2(CO)2·H2O (4), crystallographically established to contain a bidentate carbonato group, trans triphenylphosphine ligands and water hydrogen-bonded to the carbonato ligand.