Electronic Structure of Heterospirenes-PE Spectroscopic Investigations

Article abstract of DOI:10.1021/jo00353a019

The synthesis of the heterospirenes 1-9 is described and their He I photoelectron (PE) spectra are recorded.The assignment of the first PE bands is based on a comparison with fragment molecules and on molecular orbital calculations using semiempirical methods (PPP, MINDO/3). in the case of 1, 2, 4, and 5 strong spirointeraction has been elucidated.For 3 the analysis of the spectrum is hampered due to the strong overlap of the bands while for 6 the nonplanarity brings about a reduction of spirointeractions.For 7-9 the interaction between both fragments could not be detected.