100113-26-6Relevant academic research and scientific papers
Intramolecular phosphoryl transfer: Chelated phosphoramidate
Hendry,Sargeson
, p. 865 - 869 (2008/10/08)
2,4-Dinitrophenyl phosphate (DNPP) coordinated to the pentaamminecobalt(III) moiety is rapidly lyzed in aqueous base to yield the previously unobserved N,O-chelated phosphoramidate and 2,4-dinitrophenolate (DNP) ions. The chelate ring then opens to monodentate N-bound phosphoramidate. The reaction is almost quantitative (98%) at 5°C and obeys the rate law νDNP = k[CoDNPP][OH-] with k = (1.96 ± 0.03) × 10-2 L mol-1 s-1 at 25°C and μ = 1.0 M. With increasing temperature Co-O bond rupture releases increasing amounts of unreacted phosphate ester. The mechanism is argued in terms of a deprotonated ammonia attacking the adjacent P center to give an aminophosphorane, which then decomposes to the chelate phosphoramidate. Subsequent ring opening and phosphoramidate loss are ascribed to the normal conjugate base chemistry of Co(III) amine complexes. The intramolecular substitution of NH2- for the phenolate ion at the P center is very rapid compared with analogous chemistry for the uncoordinated ion.
