The kinetics of reaction of photolytically generated Fe(CO)x (x=2,3,4) with CO

Abstract
Coordinatively unsaturated iron carbonyls were generated by gas phase UV photolysis of iron pentacarbonyl. Transient infrared absorptions of these carbonyls were probed by a cw CO laser. The reaction rate of CO with Fe(CO)4 was measured to be 3.5±0.9×1010 cc mol1 s1. Reaction of CO with Fe(CO)2 was more rapid than reaction of CO with Fe(CO)3. Both reactions were over two orders of magnitude faster than the reaction of CO with Fe(CO)4. Coordinatively unsaturated metal carbonyl absorptions do not appear immediately following Fe(CO)5 photolysis. Possible explanations for this phenomenon are discussed.