Ultrafast reductive elimination of hydrogen from a metal carbonyl dihydride complex; a study by time-resolved IR and visible spectroscopy

Laser flash photolysis of [Ru(PPh 3 ) 3 (CO)(H) 2 ] 1 in benzene solution yielded transient [Ru(PPh 3 ) 3 (CO)] which was observed by both microsecond UV/VIS and IR spectroscopy [λ max = 380 nm, ν(CO) = 1845 cm - ] and reacted with H 2 to reform 1 [k 2 = (8.4 ± 0.4) × 10 7 dm 3 mol - s -1 ]; photolysis of 1 with an ultrafast laser equipped with IR detection demonstrates that reductive elimination of H 2 and formation of [Ru(PPh 3 ) 3 (CO)] is complete within 6 ps.