Photochemical C-P Bond Cleavage of Nitrobenzylphosphonate Ions

Article abstract of DOI:10.1246/bcsj.60.277

Upon UV-irradiation, the C-P bond of p-nitrobenzylphosphonate ions cleaved with a quantum yield of about 0.7 in an aqueous alcohol solution to give 1,2-bis(4-nitrophenyl)ethane, p-nitrotoluene, orthophosphate, and alkyl dihydrogenphosphate.Whereas in an aqueous solution 1,2-bis(4-nitrophenyl)ethane was produced as a main product, in an alcohol solution only p-nitrotoluene was produced.This photolysis may proceed via intramolecular electron tranfer from PO3^2- group to nitro aromatic moiety to form an excited state, which undergoes C-P bond cleavage to give p-nitrobenzyl anion and monomeric metaphosphate anion as intermediates.The C-P bond cleavage of p-nitrobenzylphosphonate ion occurred more readily than those of o- and m-nitrobenzylphosphonate ions.