Hydrolysis kinetics and mechanism of adipamide in high temperature water

Unusual Conformation of a Dinuclear Paddle Wheel Copper(II) Complex. Synthesis, Structural Characterization and EPR Studies

“…The powder EPR results are typical of isolated dinuclear species, in which a classical triplet state of Cu II can be observed. Compound 1 is also characterized by a large tetragonal zero-field parameter, and by presenting a well resolved Cu II monomer signal at T < 150 K. The intradinuclear exchange coupling J 0 of −101 ± 2 cm –1 can be compared with the values found for other reported dinuclear compounds, which are given in Table . ,− The obtained J 0 value for ( 1 ) is significantly lower compared with the reported intradinuclear exchange values for Cu II –PW with different −O–C–O– bridges (Table , compounds (6)–(12)). − The antiferromagnetic exchange coupling observed for ( 1 ) is also greater than the value measured for dinuclear compounds with two carboxylate groups (Table , compounds (2)–(5)), ,, corroborating that decreasing antiferromagnetic interactions can be related to the decrease of the number of the carboxylates bridging copper ions . The Cu–O–C–O–Cu bridge (φ bend ), the oxygen ligand at the axial positions, the dihedral angle between Cu–O–O–Cu and the carbonyl moiety, are parameters which can contribute to a decrease of the exchange parameter because of the poor overlap of the Cu d x 2 – y 2 orbital with the 2p x carboxylate oxygen orbital…”

“…Under these different synthetic conditions the final product also contains a ligand which was not used as an initial reagent. This fact can be explained using the mechanism reported in the literature, in which nitriles in aqueous medium can be converted, by two successive hydration reactions, to amides and then to ammonia and carboxylate (Scheme ) …”

Subcritical water hydrolysis of nylon 6 extract concentrate

“…The reaction is considered to be autocatalyzed by the generated amino and carboxyl groups . Additionally, the activation energy of the reaction is reduced because the ionization of subcritical water promotes the rate‐determining step of the amide hydrolysis, namely, the peptide bond attack by hydrogen or hydroxyl ions . To investigate the mechanism of amide hydrolysis in subcritical water, Duan studied the effect of acid and base on the N‐substituted amide hydrolysis in subcritical water, and found that nucleophilic substitution appeared to be a likely candidate for the hydrolysis mechanism .…”

Hydrolysis Kinetics of 2-Pyridinecarboxamide, 3-Pyridinecarboxamide and 4-Pyridinecarboxamide in High-Temperature Water

“…There is a considerable amount of literature on the hydrolysis of amide in HTW, but concentrating on aliphatic and aromatic amides [8,[12][13][14][15][16][17][18][19][20][21][22][23]. The hydrolysis of heterocyclic amides in HTW is rarely reported.…”