Oxy and Thio Phosphorus Acid Derivatives of Tin. VIII. The Tin(II) Bis-(dithiophosphate) Esters and Their Bipyridyl Adducts. The X-Ray Crystal and Molecular Structure of Bis-(O,O'-Diphenyldithiophosphato)tin(II)

摘要

Four tin(II) dithiophosphate esters, Sn(S2P(OR)2)2, where R = CH3, C2H5, i-C3H7 and C6H5 are synthesized in high yield by the action of the O,O'-diorganodithiophosphoric acids on dimethoxytin(II) in benzene to release methanol. The R = C2H5 product is a pale yellow oil, but the others are colorless crystalline solids soluble in non-polar organic solvents. The 2,2'bipyridyl adducts of the parent esters from immediately upon mixing. NMR coupling is observed from the ester groups to phosphorus, as < 3J(31P-O-C-1H)> = 15.5 Hz in the R = CH3 derivative. In the mass spectra parent molecular ions are found for all the species, but the fragments resulting from the loss of one ligand moiety are more abundant. The chief pathway for the decomposition is the successive loss of ligand moieties. Ditin-bearing ions are detected in the spectrum of the R = C2H5 derivative. The mass spectra of the bipyridyl adducts are the superposition of those of the parent tin(II) esters and of bipyridyl. The tin-119m Moessbauer isomer shifts (IS = 3.66-3.78 mm/s) confirm the presence of tin(II) and the barely resolvable quadrupole splittings (QS = 0.97-1.06 mm/s) do not increase on complexation by bipyridyl (1.03-1.15 mm/s), suggesting that the parent tin(II) esters themselves have higher coordination number in the solid state.