Conductivity in supercritical fluids

Gas-phase studies have not been restricted to the group VI hexacar-bonyls. Fu and co-workers (54) have used TRIR to study the coordina-tively unsaturated species CpMn(CO) (x = 1 and 2) generated by 266-and 355-nm laser photolysis of CpMn(CO)3 in the gas phase. In the presence of noble gas L (L = He, Ar, or Xe), they were able to measure the rate constant for reaction of the noble gas complex CpMn(CO)2L with CO. Interestingly, they foimd that only Ar significantly perturbed the rate fi om that observed in the absence of noble gas. This was thought to be because He has too high an ionization potential and Xe is too bulky to interact with the Mn center. In light of recent TRIR experiments conducted in supercritical fluid solution, the conclusion that Xe is unable to coordinate is incorrect. 

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