8 and 16-Membered ring phosphorus compounds. Ring size dependence of the NMR parameters

The ¹H NMR spectral analysis of four 8-membered rings, 2-thioxo- (or 2-oxo-) 2-R-1,3,6,2- trithiaphocane, is reported. The stereochemistry of the 8-membered ring is discussed. The ³¹P NMR spectral parameters δ³¹P, ¹J(PC)] obtained on several cyclic 1,3,2-dithiaphospha compounds of variable size (5, 6, 8, 12 and 16-membered rings) are discussed as a function of the ring size and of the geometry of the molecule.