PRIMARY VINYLSTIBINES AND ALKYNYLSTIBINES - PREPARATION AND CHARACTERIZATION

Primary unsaturated stibines ethenylstibine (1a), E-prop-1-enylstibine (Ib), ethynylstibine (2a), and prop-1-ynylstibine (2b) are synthesize d by reaction of antimony trichloride with the corresponding vinyltrib utylstannanes 3a,b and alkynyltributylstannanes 4a,b, respectively, fo llowed by a chemoselective reduction of the formed dichlorostibines 5a ,b and 6a,b. Compounds 1a,b and 2a,b are characterized on the basis of spectral data (NMR, photoelectron spectroscopy and high resolution ma ss spectrometry). In particular, the PE spectra display very well-reso lved bands (1a, 9.3, 10.3, 11.2, 11.9, 13.7. and 15.0 eV; 2a. 9.7, 10. 5, and 11.2 eV). The alpha-unsaturated stibines exhibit a low stabilit y at room temperature even in the presence of a solvent (tau(1/2) ca. 1 h) and lead to the formation of oligomeric material or an antimony m irror on the wall of the flask. Attempts to detect C-Sb multiple bond derivatives by a base-catalyzed rearrangement of 1 or 2 were unsuccess ful.