Kinetic Isotope Effects and Pressure Effects in Several Hydrogen-Transfer Reactions of Tetralin and Related Compounds

Article abstract of DOI:10.1021/jo00213a002

The H/D kinetic isotope effects and activation volumes have been measured for several hydrogen-transfer reactions using tetralin, dihydronaphthalenes, cyclohexa-1,4-diene, and cyclohexanol as donors.The isotope effects were found to exhibit different patterns for reactions of different mechanisms.They indicate whether hydrogen is in transit in the activated complex and show the number of atoms in transit (one or two).The KIE for the reaction of tetralin with quinones is consistent with concerted transfer of two hydrogens whereas the other reactions were found to be stepwise.The activation volumes lie within the range -23 to -33 mL/mol and do not seem to differetiate among bimolecular mechanisms.The relevance to previous studies of the KIE and ΔV(excit.) for coal hydrogenation reactions is discussed.