Gas-phase characterization by photoelectron spectroscopy of unstabilized α-unsaturated arsines: Ethylidene- and ethylidynearsines
Résumé
Primary unsaturated arsines, vinylarsine (1), prop-1-enylarsine (2), and ethynylarsine (3), prepared by a chemoselective reduction of the corresponding dichloroarsines, have been characterized in the gas phase by their photoelectron (PE) spectra. Their base-induced rearrangements on solid K2CO3, in vacuum gas-solid reactions (VGSR) conditions, led, respectively, to ethylidenearsine (4), propylidenearsine (5), and ethylidynearsine (6). For the first time, electronic structures of primary α-unsaturated arsines and low-oordinate arsenic compounds are evidenced and the coherence with phosphorus analogues is confirmed. In particular, six narrow and well-resolved bands at 9.6, 10.6, 11.9, 12.7, 14.0, and 15.4 eV are observed in the PE spectra of 1, and the spectrum of 3 exhibits three ionizations at 9.9, 10.6, and 11.6 eV. The spectra attributed to 4 and 5 display a broad band with a shoulder at 9.6 and 10.3 eV and at 9.5 and 10.2 eV, respectively. Two well-resolved bands at 9.6 and 12.1 eV are observed for 6. © 1995 American Chemical Society.