The diorganotin compounds, [Me2Sn{OOP(OBun)2}2] (II), [Me2Sn{OSP(OBun)2}2] (III) and [Me2Sn{SSP(OBun)2}2] (IV), have been investigated by C-13, P-31 and Sn-119 solution state NMR as well as solid state NMR. On the basis of these studies it is suggested that the phosphate ligand acts in a symmetrical chelating fashion in II, while the ligands behave in an anisobidentate manner in III and IV.