Hydroxylamine as an oxygen nucleophile. Direct evidence from its reaction with a phosphate triester

Materials: All solutions were prepared using distilled water. Hydroxylamine (Aldrich, 98%), p-dimethylaminobenzaldehyde (Aldrich, 98%,) fumaric acid (Carlo Erba, 99.5%), succinic acid (Vetec, 99%), tris(hydroxymethyl)aminomethane (TRIS, Aldrich, 99%), N,O-Bis(trimethylsilyl)trifluoroacetamide (Aldrich, >99%) and D2O (Cambridge Isotope Laboratories, 99.9%) were used as supplied. The triester diethyl 2,4-dinitrophenyl phosphate was prepared according to the procedure of Moss and Ihara. The color reagent employed to detect N2H4 was prepared as described by Watt and Chrisp. H and P NMR spectra were recorded in D2O at 400 and 162 MHz, respectively, using a Varian Mercury Plus 400-MHz instrument: with sodium 3(trimethylsilyl) propionate (TSP) as internal reference for H NMR and 85% phosphoric acid as external reference for P NMR spectra. Mass spectroscopy was performed in a Shimatzu GCMS5050A instrument, operating with a DB5 column (Agilent) with He as carrier gas. The injector and interface temperature were kept at 280 and 300°C, respectively, and the oven temperature kept for 5min at 80°C then raised, with a constant rate of 10°C/min, to 300°C for 5min.