Photoelectron spectra and fluxional behaviour in some σ-cyclopentadienes
Abstract
A close correlation is shown to exist between fluxional behaviour in the σ-cyclopentadienes 5-RC5H5(R = H, CH3, SiH3, GeH3, or SiF3) and the relative positions of the two photoelectron bands due to the ring π-bonding electrons. For R = PF2 and SiCl3 interactions between the second ring level and non-bonding orbitals of R have to be taken into account. It is suggested that the fluxional behaviour arises from interaction of R–C5σ-bonding level with the symmetric ring π-bonding level, which is greatest in those compounds that show fast fluxional behaviour.