DFT investigation on the intramolecular and intermolecular proton transfer processes in 2-aminobenzothiazole (ABT) in the gas phase and in different solvents

DFT at the B3LYP/6-311++G(d,p) level of theory was performed to geometrically, thermodynamically, and kinetically investigate the tautomerism process of 2-aminobenzothiazole (ABT) with n water molecules (n = 1–3) and without water in the gas phase and in different solvents with a gradual increase in their dielectric constants. The geometries of the envisaged tautomers were optimized in the gas phase and in solution with the polarized continuum model (PCM). Equilibrium and rate constants for the forward and reverse intra-/intermolecular isolated and water-assisted tautomerism reactions were also calculated. The results suggest that the activation energy of the transition state of direct proton transfer in the isolated reaction is very high and that the rate constant is very slow (~ 10^?24 s), reflecting that the reaction is thermodynamically unfavored, whereas the barrier differences between the transition states of the tautomers decrease gradually as the number of water molecules increases from one to three. Moreover, the rate constants of the proposed reactions are ~ 10²³–10²⁵ faster than those of the isolated reaction, and the water-assisted tautomerism paths can be performed quickly, especially with the assistance of two molecules of water.

     

Investigation of optoelectronic properties of triphenylamine-based dyes featuring heterocyclic anchoring groups for DSSCs’ applications: a theoretical study

Structural Chemistry - Design and synthesis of new potent sensitizers are of interest for realization of high-efficiency Dye Sensitized Solar Cells (DSSCs). Modification of the...     

Structure Determination and Quantum Chemical Analysis of 1,3-Dipolar Cycloaddition of Nitrile Imines and New Dipolarophiles and POM Analyses of the Products as Potential Breast Cancer Inhibitors

Russian Journal of Organic Chemistry - The 1,3-dipolar cycloaddition of nitrile imines to 11-aryl-4-(arylmethylidene)-1,2,3,4,11,11a-hexahydrodibenzo[b,e][1,4]thiazepines possessing exocyclic C=C...     

New azoloazine derivatives as antimicrobial agents: Synthesis under microwave irradiations,structure elucidation,and antimicrobial activity

With aiding of microwave radiation, new series of fused-thiazolopyrimidines and fused-triazolopyrimidines each with cycloheptane have been synthesized through the reaction of cycloheptane-thione with α-haloketones or hydrazonoyl chlorides in short-time intervals as well as high yield. Moreover, reaction of 2,7-bis(2-chlorobenzylidene)cycloheptan-1-one with o-aminothiophenol and heterocyclic amines afforded benzo[b]cyclohepta[e][1,4]thiazepine derivative and cycloheptapyrimidines fused with different azoles, respectively. The structure for all products was discussed and proved based on the results of spectral data and elemental analysis. Evaluation of the antimicrobial activity of selected products indicated that most of derivatives showed their potent activity exceeds the reference antibiotic in some cases.