7413-60-7

Upstream product

• 100-02-7 4-nitro-phenol 
• 1738-86-9 Z-Gly-ONp 

Downstream Products

• 33096-26-3 o-Nitrophenylsulphenyl-N-2-cyanethyl-glycylglycin-p-nitrophenylester 
• 6234-22-6 N--glycin-<4-nitro-phenylester> 
• 25044-65-9 N-Nitroso-sarkosyl-glycin-<4-nitro-phenylester> 
• 112120-62-4 Boc-Lys(Z)-Gly-ONp 
• 112120-80-6 Boc-Asp(OBzl)-Gly-ONp 
• 74802-13-4 t-butyloxycarbonyl-L-kynurenylglycine p-nitrophenyl ester 
• 100-02-7 4-nitro-phenol 
• 112120-83-9 Z(OMe)-Gly-Lys(Z)-Gly₂-ONp 

Relevant academic research and scientific papers

Kinetics and mechanism of the cobalt(III) tetraammine complex-promoted hydrolysis of 4-nitrophenyl glycinate

The kinetics of the hydrolysis of 4-nitrophenyl glycine ester (PNPG) catalysed by [Co(OH)(trien)(OH2)]2+, [Co(OH)(tren)(OH2)]2+ and [Co(OH)(en)2(OH2)]2+ complexes has been studied spectrophotometrically in weakly basic aqueous media (pH = 6.5 to 7.4). Kinetic experiments were carried out as a function of the pH, complex concentration and temperature. The rate of hydrolysis increases linearly with the complex concentration with a trend to wards rate saturation, suggesting the formation of associative species in a pre-equilibrium step. The pseudo-first order rate constant, kobs, increases rapidly with a decrease in the hydrogen-ion concentration. The complexes promote the hydrolysis of 4-nitrophenyl glycinate significantly, and the acceleration rate is about 400-600. An attack of external OH- on the chelated ester is suggested as a probable mechanism for the hydrolysis. The lower rate enhancements observed in the present study could probably be ascribed to a weaker cobalt(III) alkoxy carbonyl interaction in the chelate, owing to a decreased nucleophilicity of the carbonyl oxygen in the p-nitrophenyl ester. The activation parameters for all three complex-promoted reactions are found to be comparable, thus suggesting a common mechanism operative in all complex catalysed reactions.