h(1)-2-pyrone metal carbonyl complexes as CO-releasing molecules (CO-RMs): A delicate balance between stability and CO liberation

An evaluation of the CO releasing ability of iron(II) and molybdenum( II) complexes has facilitated the discovery of the most rapid CO releaser, namely [Mo( CO) 3(eta(5)-C5H5)(eta(1)-{O} C{= O}-O-CMe=CH-COMe=CBr)]BF4 (CORM-F10), reported to date. The rate of CO release is related to the overall solution phase stability of the transition metal carbonyl complex. The cytotoxity and vasodilatory properties of CORM-F10 have been determined.