title: A delicate balance of complexation vs. activation of alkanes interacting with [Re(Cp)(CO)(PF3)] studied with NMR and time-resolved IR spectroscopy.
abstract: The organometallic alkane complexes Re(Cp)(CO)(PF(3))(alkane) and Re(Cp)(CO)(2)(alkane) have been detected after the photolysis of Re(Cp)(CO)(2)(PF(3)) in alkane solvent. NMR and time-resolved IR experiments reveal that the species produced by the interaction of n-pentane with [Re(Cp)(CO)(PF(3))] are an equilibrium mixture of Re(Cp)(CO)(PF(3))(pentane) and Re(Cp)(CO)(PF(3))(pentyl)H. The interaction of cyclopentane with [Re(Cp)(CO)(PF(3))] most likely results in a similar equilibrium between cyclopentyl hydride and cyclopentane complexes. An increasing proportion of alkane complex is observed on going from n-pentane to cyclopentane to cyclohexane, where only a small amount, if any, of the cyclohexyl hydride form is present. In general, when [Re(Cp)(CO)(PF(3))] reacts with alkanes, the products display a higher degree of oxidative cleavage in comparison with [Re(Cp)(CO)(2)], which favors alkane complexation without activation. Species with the formula Re(Cp)(CO)(PF(3))(alkane) have higher thermal stability and lower reactivity toward CO than the analogous Re(Cp)(CO)(2)(alkane) complexes.
authors: School of Chemistry, University of New South Wales, Sydney 2052, Australia. gball@unsw.edu.au
authors: Graham E
authors: GE
authors: Ball
authors: Christopher M
authors: CM
authors: Brookes
authors: Alexander J
authors: AJ
authors: Cowan
authors: Tamim A
authors: TA
authors: Darwish
authors: Michael W
authors: MW
authors: George
authors: Hajime K
authors: HK
authors: Kawanami
authors: Peter
authors: P
authors: Portius
authors: Jonathan P
authors: JP
authors: Rourke