(4-Nitrophenyl)phosphonic acid (p-Nitrophenyl)phosphonic acid 2175-86-2 4-16-00-01084 (Beilstein Handbook Reference) 4-Nitrophenyl phosphonate BRN 2727470 NSC 420 Phosphonic acid, (4-nitrophenyl)- (9CI) Phosphonic acid, (p-nitrophenyl)-