Organoantimony(V) Phosphinates, Phosphonates, and Seleninates

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 [Ph3Sb(HPhPO2)(2)](2) (1), [Ph3Sb(Ph2PO2)(2)] (2), [Ph3Sb(tert-BuPO3H)(2)] (3), [Ph3Sb(PhSeO2)(2)](2) (4), and [(Ph3Sb)(2)(-O)(-PhSeO2)(2)] (5), respectively. Hydrolysis and dearylation of 3 yielded [(Ph2Sb)(2)(PhSb)((3)-O)((2)-O)(2)(OH)(2)(-tBuPO(3))(2){(C2H5)(4)N}(2)] (6) possessing in situ generated Ph2Sb(O)(OH) and PhSbO3H2 moieties. The P-31 NMR spectrum of 1 shows P-H three-bond coupling seen for the first time in organophosphorus-based compounds. Further P-31 NMR spectroscopy at lower temperatures revealed 1 to be a fluxional molecule. Se-77 NMR spectroscopy indicates the formation of different molecular clusters from crystallization processes carried out under varying solvent conditions.