A theoretical study of the tautomerism kinetics of 4-amino-6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one in the gas phase: NBO population and NICS analysis

Abstract

Supporting InformationTable S1. Rotational moments of inertia and vibrational frequencies calculated at the M06-2x/aug-cc-pVTZ theoretical level for tautomeric reaction. Tautomer 1 Tautomer 2 TS Frequencies (cm 1 )

Theoretical investigations on the HOMO–LUMO gap and global reactivity descriptor studies, natural bond orbital, and nucleus-independent chemical shifts analyses of 3-phenylbenzo[d]thiazole-2(3H)-imine and itspara-substituted derivatives: Solvent and substituent effects

“…The synthesis of 3-phenylbenzo[d]thiazole-2(3H)-imine and its para-substituted derivatives (3a-f) was carried out by reaction of different synthesized N-acyl-N′-aryl thioureas (1a-f) with diazonium salts (2). The optimized structures of all the compounds (see Scheme 1) were then investigated by comprehensive computational studies and are presented in Supplemental Figure S1.…”

“…As can be seen in Table 4, the para functional group will further influence the HOMO and LUMO energy levels in the studied compounds (1)(2)(3)(4)(5)(6). Electron-withdrawing substituents lead to a decrease in the energy levels of the frontier orbitals whereas electron-donating groups have the opposite effect.…”

“…The values of the LUMO-HOMO energy gap reflect the chemical activity of the molecule. The decrease in the HOMO-LUMO energy gap explains the eventual charge transfer interaction taking place within the studied compounds [1][2][3][4][5][6] because of the strong electron-accepting ability of the electron acceptor group (Table 4). As a result, the stability of the studied compounds is 1 > 3 > 2 > 4 > 5 > 6.…”

“…Fused heterocyclic compounds are key valuable and structural scaffolds in a broad variety of natural products, drug molecules, and functional materials. [1][2][3] Among them, research on benzothiazoles, organosulfur heterocyclic compounds has become a rapidly developing and increasingly active topic. Such compounds are used as building blocks in organic synthesis due to their wide range of biological activities, and they form core in various drugs such as anticancer, antimicrobial, antiasthmatic, antitumor, antibacterial, antitubercular, anticonvulsant, anti-HIV, anti-inflammatory, antifungal, antiproliferative, antiviral, anti-Alzheimer, antimalarial, and anti-diabetic, agents.…”

DFT study and NBO analysis of solvation/substituent effects of 3-phenylbenzo[d]thiazole-2(3H)-imine derivatives

“…Fused heterocyclic compounds are the key valuable and structural scaffolds in a wide range of natural products, drug molecules, and functional materials. 1,2 Among them, the related research on benzothiazole analogs is an organosulfur heterocyclic compound that has become a rapidly developing and increasingly active topic. The significant role of these groups of compounds are used as building blocks in organic synthesis due to their wide variety biological activities as core nucleus in various drugs such as anticancer, antimicrobial, antitumor, antibacterial, anti-HIV, antifungal, antiviral, anti-Alzheimer, antimalarial, and anti-diabetic, etc.…”