Diselenadiphosphetane diselenides and triselenadiphospholane diselenides -Synthesis and characterization by P-31 and Se-77 solid-state MNR spectroscopy

1,3-Diselena-2,4-diphosphetane-2,4-diselenides (RPSe2)(2) with R = Me, Et, t-Bu, Ph, 4-Me2NC6H4, 4-MeOC6H4 have been synthesized by different methods. The insoluble compounds were investigated by P-31 and Se-77 solid-state NM R and the purity of the compounds has been checked by their CP MAS sideband NMR spectra. The structure of the investigated compounds has been confirme d by the isotropic and anisotropic values of the chemical shifts and the (1 )J(P-Se) coupling constants. In addition, two new 1,2,4-triselena-3,5-dipho spholane-3,5-diselenides, (RPSe2)(2)Se (R = Me, Et), formed under similar s ynthesis conditions, were investigated. Their structure was derived from th e Se-77 satellites P-31 solution spectra and from solid-state spectra. For (t-BuPSe2)(2) the experimentally obtained principal values of phosphorus an d selenium shielding tensors are compared with values from IGLO calculation s (HF und SOS DFPT). The calculated orientations of the principal axes are discussed.