title: Base Hydrolysis of Methyltrioxorhenium. The Mechanism Revised and Extended: A Novel Application of Electrospray Mass Spectrometry.
abstract: The full kinetic pH profile for the base-promoted decomposition of MTO to CH(4) and ReO(4)(-) was examined with the inclusion of new data at pH 7-10. Spectroscopic and kinetic data gave evidence for mono- and dihydroxo complexes: MTO(OH(-)) and MTO(OH(-))(2). Parallel unimolecular eliminations of methane from these species account for the rate-pH profile; the respective rate constants are MTO(OH(-)), k = 4.56 x 10(-)(5) s(-)(1) and MTO(OH(-))(2), k = 2.29 x 10(-)(4) s(-)(1) at 25 degrees C. Some kinetic data were acquired with electrospray mass spectrometry to monitor the buildup in the concentration of perrhenate ions. Reliable signals for each of the isotopomers of ReO(4)(-) were obtained by this method with initial MTO concentrations of 160 &mgr;M.
authors.affiliation: The Ames Laboratory and Department of Chemistry, Iowa State University, Ames, Iowa 50011.
authors.forename: James H.
authors.initials: JH
authors.lastname: Espenson
authors.forename: Haisong
authors.initials: H
authors.lastname: Tan
authors.forename: Sahana
authors.initials: S
authors.lastname: Mollah
authors.forename: R. S.
authors.initials: RS
authors.lastname: Houk
authors.forename: Matthew D.
authors.initials: MD
authors.lastname: Eager