The negligible double kinetic deuterium isotope effect (kHH/kDD = 1.05) in the reaction where [2,3,4,5-Ph4(η5-C4COH)Ru(CO)2H (2) transfers a hydride and a proton to N-phenyl-[1-(4-methoxyphenyl)ethylidene]amine (4) indicates that no bond to hydrogen is broken or formed in the rate-determining step.
