The UV gas-phase photoelectron spectra of group IVB tetraphenyl derivatives

The He(Iα) and He(IIα) photoelectron spectra of the M(C₆H₅)₄ series of molecules (M = C, Si, Ge, Sn, Pb) have been recorded and analysed on the basis of correlations with the known electronic structures of corresponding MH₄ hydrides and of benzene. Extended Hückel MO calculations were also performed for all the molecules in the series. The photoelectron spectra of the M(C₆H₅)₄ molecules all bear a strong resemblance to the benzene spectrum, suggesting that there are only weak interactions between the phenyl ligands.