Photoelectron spectra and molecular properties. - L : On the blue color of bis(trimethylsilyl)diimine

Abstract

Photoelectron (PE) and uv spectra of group 4 azo compounds R3X-N=N-YR3 (X, Y = C, Si) and H5C6-N=N-XR3 (X = C, Si, Ge) are reported. A comparative discussion, based on CNDO calculations, attributes the low ionization potentials of the trimethylsilyl derivatives to substantial electron donation from the R3Si substituents. The unique electronic spectrum of the title compound can be rationalized considering in addition electron-electron interaction as well as Rydberg excitations.