Novel carbon dioxide and carbonyl carbonate complexes of molybdenum. The X-ray structures of trans-[Mo(CO2)(2){HN(CH2CH2PMe2)(2)}(PMe3)] and [Mo-3(mu(2)-CO3)(mu(2)-O)(2)(O)(2)(CO)(2)(H2O)(PMe3)(6)]center dot H2O

A new bis(carbon dioxide) adduct of molybdenum containing the tridentate, bis( phosphine) ligand, HN(CH2CH2PMe2)(2) (NP2), in a mer conformation has been synthesized and structurally characterized. Its carbonyl carbonate isomer [Mo(CO3)(CO)(NP2)(PMe3)] has also been prepared. In addition, the reactivity of the complex [Mo(CO3)(CO)(PMe3)(4)] toward CO has been studied, a transformation that has led to the formation of the dicarbonyl complex [Mo(CO3)(CO)(2)(PMe3)(3)]. This complex liberates CO2 upon heating under a carbon monoxide atmosphere by means of a CO-CO3 conproportionation reaction. The new trinuclear complex [Mo-3(mu(2)-CO3)(mu(2)-O)(2)(O)(2)(CO)(2)(H2O)(PMe3)(6)].H2O, resulting from the interaction of [Mo(CO3)(CO)(PMe3)(4)] and water, has been isolated and structurally characterized.