Abstract: | Abstract Compounds of the following structure (R1O)2(X)P[sbnd]Y–P(X)(OR2)2 (X = O, Y = Sn (n = 1–4), R1 = R2 = Me, iPr; X = S, Y = Sn (n = 1–4), R1, R2 = Me, Et, iPr, iBu; X = S, Y = S-Se-S, S-Te-S, R1 = R2 = Me were prepared and their NMR spectra were analysed. Depending on the number of sulfur atoms, bonded between the phosphorus atoms, typical ranges of the P-P coupling constants were found for the different sulfanes investigated: 2JPP from-10 to-20 Hz, 3JPP less than 3 Hz, 4JPP from +10 to +13 Hz and 5JPP less than 1 Hz. For the small vicinal coupling constants and the relatively large values of 4JPP different possibilities of their interpretation are given. |