Photolytic products, metal-carbonyl complexes

However, while ruthenium carbonyl was found to decompose the formate ion in basic media, the rate was slower (<0.1 mmol trimethyl ammonium formate to H2 and C02 per hour) than the rate of the water-gas shift reaction (>0.4 mmol H2/hr) at 5 atm CO and 100 °C. Increasing CO pressure decreased the formate decomposition rate. However, it was observed that increasing the CO pressure from 5 atm CO to 50 atm increased the H2 production rate to 10 mmol/hr. They proposed, in a similar manner to Pettit et al.,34 a mechanism that involved nucleophilic attack by amine (instead of hydroxide). Activation of the metal carbonyl (e.g., Ru3(CO) 2 cluster to Ru(CO)5) was suggested to be favored by dilution, increases in CO pressure, or, in the case of Group VIb metal carbonyl complexes, photolytic promotion. The mechanism is shown below in Scheme 9 ... 

The reaction of Group 7 metal carbonyl Re2(CO)i0 with Ph2SiH2 under photolytic conditions was reported to give a bridged silylene complex with hydrides on the Re atoms [Eq. (10)).33 The X-ray structure analysis of this product and also those of Re2(CO)6H4(/u.-SiEt2)234 and Re2(CO)7H2 (pt-SiEt2)235 have been reported, but the bonding mode, that is, whether the Si—H bond is fully oxidatively added or not, is still controversial.1011... 

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