A New Class of Eight-Membered Sn2P2O4 Heterocycles. Crystal Structure and Electrolytic Dissociation in Solution of cyclo-[R2Sn(OPPh2O)2SnR2](O3SCF3)2 (R = Me, t-Bu)

Abstract

The syntheses of cyclo-[R 2 Sn(OPPh 2 O) 2 SnR 2 ]-(O 3 SCF 3 ) 2 (R = Me (1), t-Bu (2)) by the consecutive reaction of R 2 SnO (R = Me, t-Bu) with triflic acid and diphenylphosphinic acid are presented. In the solid state, 1 and 2 were investigated by 1 1 9 Sn MAS and 3 1 P MAS NMR spectroscopy as well as X-ray crystallography and appear to exist as ion pairs of cyclo-[R 2 Sn(OPPh 2 O) 2 -SnR 2 ] 2 + dications and triflate anions. In solution, 1 and 2 are involved in extensive equilibria processes featuring cationic diorganotin(IV) species with Sn-O-P linkages, as evidenced by 1 1 9 Sn and 3 1 P NMR spectroscopy, electrospray mass spectrometry, and conductivity measurements.