Knowledge Bank

The He(I) photoelectron spectra of the Group V phenyl compunds $C6H5XH2$ (where X = N and P), $(C6H5)2XH$ (where X = N, P and As) and $(C6H5)3X$ (where X = N, P, As and Sb) have been obtained. The spectra of dichloro- and dimethylphenylphasphine have also been measured along with that of benzylamine. The observed ionization bands have been identified through vibrational analysis, CNDO/2 calculations, substitution effects, and intensity considerations. Evidence for d-orbital participation in the organo-metallics is presented. The relative magnitudes of participation for the various central atoms have been obtained from correlation diagrams of the energy levels. The degree of participation is directly related to the shifts observed for the non-bonding orbital and participating $\Pi$ orbitals of the phenyl moiety. The importance of d-orbital participation in the Group V elements has been shown to be $P>As>Sb$. The spectra of these molecules are consistent with the $----1a2u(\Pi )$, $3e2g(\sigma )$, $le1g(\Pi )$ MO order in benzene. Vibrational structure in the ``X-sensitive” and C-C stretching modes was observed in the outermost bands of aniline.