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The reactivity of a series of N-arylacetamides, R--C(sub 6)H(sub 4)--NHCOCH(sub 3), with respect the alkaline hydrolysis reaction is studied. The electrostatic potential at the nuclei is recommended as an accurate local reactivity index.

Research has been conducted on the amide carbon-nitrogen bond. The role of the polar substituents in the internal rotation barrier around this bond has been investigated via the use of the density functional theory and the linear dependence between the rotation barriers and frequency shifts has been discovered.

A study was conducted to examine the kinetics of the aminolysis process for a series of seven parasubstituted phenyl acetate derivatives containing both electron-withdrawing and electron-donating groups. The electrostatic potentials observed at the carbon atom of the carbonyl reaction center provide insight into both the theoretical barrier heights and experimental rate constants.

The variations of barrier heights for rotation around the amide C-N bond in para-substituted thioacetanilides was studied in a comparative context with data for a series of acetanilides by applying density functional theory. The results obtained were consistent with the views for a classical amide resonance as being the origin of higher rotational barriers in thioamides than in amides.

Density functional theory computations with the B3LYP/6‐311++G(2df,2p) method and IR spectroscopy are employed in investigating the properties of twenty π‐hydrogen bonded complexes between substituted phenols and hexamethylbenzene. All complexes possess T‐shaped structures. The methyl hyperconjugative effects on interactions energies and OH stretching frequencies are estimated via comparisons with previously reported theoretical and experimental results for analogous phenol complexes with benzene. The theoretical computations provide excellent quantitative predictions of the OH stretching frequency shifts (ΔνOH) resulting from the hydrogen bonding. The ΔνOH shifts in the hexamethylbenzene complexes are approximately twice as large as the corresponding shifts for the benzene complexes. Hirshfeld charges, electrostatic potential at nuclei values, and molecular electrostatic potential maps are employed in gaining insights into the mechanisms of methyl hyperconjugative effects on complex formation. © 2017 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Theoretical computations and experimental kinetic measurements were applied in studying the mechanistic pathways for the alkaline hydrolysis of three secondary amides: N-methylbenzamide, N-methylacetamide, and acetanilide. Electronic structure methods at the HF/6-31+G(d,p) and B3LYP/6-31+G(d,p) levels of theory are employed. The energies of the stationary points along the reaction coordinate were further refined via single point computations at the MP2/6-31+G(d,p) and MP2/6-311++G(2d,2p) levels of theory. The role of water in the reaction mechanisms is examined. The theoretical results show that in the cases of N-methylbenzamide and N-methylacetamide the process is catalyzed by an ancillary water molecule. The influence of water is further assessed by predicting its role as bulk solvent. The alkaline hydrolysis process in aqueous solution is characterized by two distinct free energy barriers: the formation of a tetrahedral adduct and its breaking to products. The results show that the rate-determining stage of the process is associated with the second transition state. The entropy terms evaluated from theoretical computations referring to gas-phase processes are significantly overestimated. The activation barriers for the alkaline hydrolysis of N-methylbenzamide and acetanilide were experimentally determined. Quite satisfactory agreement between experimental values and computed activation enthalpies was obtained. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]