Organoantimony(V) phosphinates, phosphonates, and seleninates

Abstract

The reaction of polymeric triphenylantimony oxide with various protic ligands like phenylphosphinic acid, diphenylphosphinic acid, tert-butylphosphonic acid, and phenylseleninic acid has been investigated. Single-crystal X-ray structural elucidation revealed the formation of [Ph 3Sb(HPhPO2)2]2 (1), [Ph 3Sb(Ph2PO2)2] (2), [Ph 3Sb(tert-BuPO3H)2] (3), [Ph 3Sb(PhSeO2)2]2 (4), and [(Ph 3Sb)2(μ-O)(μ-PhSeO2)2] (5), respectively. Hydrolysis and dearylation of 3 yielded [(Ph2Sb) 2(PhSb)(μ3-O)(μ2-O)2(OH) 2(μ-tBuPO3)2{(C2H 5)4N}2] (6) possessing in situ generated Ph2Sb(O)(OH) and PhSbO3H2 moieties. The 31P NMR spectrum of 1 shows P-H three-bond coupling seen for the first time in organophosphorus-based compounds. Further 31P NMR spectroscopy at lower temperatures revealed 1 to be a fluxional molecule. 77Se NMR spectroscopy indicates the formation of different molecular clusters from crystallization processes carried out under varying solvent conditions. Depolymerization of triphenylantimony oxide in the presence of protic ligands has led to the isolation of interesting eight-membered organoantimony rings incorporating either phosphorus or selenium atoms as a part of the ring system. 31P and 77Se solution NMR spectroscopy reveals interesting insights about the structures of the isolated products. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.