Following CO and H Insertion into Ru-C Bonds with X-ray Photoelectron and Absorption Spectroscopies.

Insertion reactions play a central role in the catalytic synthesis of ethanol and higher alcohols. X-ray photoelectron and absorption spectroscopies have been used to follow migratory CO insertion and C─C coupling in a cis-[Ru(2,2'-bipyridine)2(CO)(CH3)]+ complex heated in a vacuum or exposed to CO. Heating of the Ru complex in a vacuum to temperatures above 50 °C induced spontaneous migration of CO into the Ru─CH3 bond to yield a ─COCH3 ligand. After adding CO to the background gas, the CO insertion reaction was seen at room temperature, opening the door for the synthesis of ethanol and more energy dense liquids.