The character of buffer-catalyzed hydrolysis of four phosphonates, bis
-(4-nitrophenyl) methylphosphonate (NMN), 4-nitrophenyl 2-propyl methy
lphosphonate (IMN), 2-(3,3-dimethyl)butyl methylphosphonofluoridate (s
oman), and 4-nitrophenyl 4-methylphenacyl methylphosphonate (MPMN), wa
s investigated. The latter hydrolyzes by an intramolecular nucleophili
c mechanism. The transition state for each reaction is discussed.