Probing Delocalization in Stable Silylenes: Core Excitation Spectra of Si(NRCHCHNR), Si(NRCH2CH2NR), H2Si(NRCHCHNR), and H2Si(NRCH2CH2NR) (R = tBu)

The silicon 1s, 2p, and 2s, carbon 1s, and nitrogen 1s gas-phase core excitation spectra are reported for two stable divalent silylenes, Si(NRCHCHNR) and Si(NRCH2CH2NR) (R = tBu), and for the two analogous tetravalent dihydridosilane molecules, H2Si(NRCHCHNR) and H2Si(NRCH2CH2NR) (R = tBu). The nature of the excited states arising from one-electron core → π* and core → σ* excitations at different sites on the silylene ring are examined by …