Dynamic solvent effects in the degenerate isomerization of a hexafluoroacetone anil studied by high-pressure F-19 NMR

The rate of the degenerate isomerization of N-hexafluoroisopropylidene-N',N '-dimethyl-p-phenylenediamine was measured by high-pressure F-19 NMR spectr oscopy in a viscous hydrocarbon, 2,4-dicyclohexyl-2-methylpentane. Pressure -induced retardations that cannot be rationalized within the framework of t he transition state theory (TST) were observed, and it was concluded that t he reaction was cast into the TST-invalid nonequilibrium conditions by high pressure.