The Raman Spectrum and Aromatic Stabilization in a Cyclic Germylene

Abstract

For the stable germylene, N,N'-di-tert-butyl-1,3-diaza-2-germacyclopent-4-en-2-ylidene, 2, the Raman line for the cyclic C=C stretching mode is strongly enhanced and shifted to longer wavelength, compared with that in reference compounds. The enhancement and frequency shift are even greater than those found for the corresponding stable silylene 1. These results, along with NMR evidence and theoretical calculations, suggest that the aromatic electron delocalization is even greater in the germylene than that in the silylene.