The syntheses of triorganosilyl- and triorganostannyl-substituted diorganophosphonites as well as an evaluation of their Lewis basicity are reported. Reactions of triphenylsilyl-dialkylphosphonites with selenium proceed via initial formation of spectroscopically observable P-oxidation products that are unprecedented for phosphine derivatives with P−Si bonds.
Reactions of metalated diorganophosphonite boranes with triorganosilyl and -germyl halides provided borane adducts of diorgano(tetryl)phosphonites. Further treatment with excess Et3N or DABCO yielded the borane-free species (RO)2P-ER′3 (E=Si, Ge; R, R′=alkyl, aryl). The products of all reactions were characterized by elemental analyses and NMR data, and in selected cases by MS and single-crystal XRD studies. Reactions of selected ligands with Ni(CO)4 and selenium were shown to produce Ni(CO)3-complexes or diorgano(tetryl) phosphonoselenoates (RO)2(R′3E)P=Se, respectively, which were identified spectroscopically but could not be isolated. Evaluation of the TEP and 1
PSe coupling constants were used for a first assessment of the electron donor properties of the new molecules.Zum Volltext