Depending on the selected DFT functional, two different mechanisms are found for two organic reactions (an intramolecular nucleophilic aromatic substitution and a nucleophilic addition on a carbonyl moiety). Indeed, B3LYP predicts a concerted mechanism whereas M06-2X foresees a multistep one. Calculations at the MP4(SDQ) level proved the mechanisms to be stepwise. We studied these reactions wit...

The intramolecular alpha-arylation of aldehydes via organo-SOMO catalysis was investigated using density functional theory (B3LYP and M06-2X functionals). The geometries, spin densities, Mulliken charges, and molecular orbitals of the reacting enamine radical cations were analyzed, and the nature of the resulting cyclized radical cation intermediates was characterized. In agreement with experim...

A combinatorially optimized, range-separated hybrid, meta-GGA density functional with VV10 nonlocal correlation is presented. The final 12-parameter functional form is selected from approximately 10 × 10(9) candidate fits that are trained on a training set of 870 data points and tested on a primary test set of 2964 data points. The resulting density functional, ωB97M-V, is further tested for tr...

A supramolecular fluorophore, 1,3,5-tris(4'-aminophenyl)benzene (TAPB), selectively senses polynitroaromatic compounds (PNAC), viz. 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT), picric acid (PA), m-dinitrobenzene (m-DNB) and p-dinitrobenzene (p-DNB) through donor-acceptor complexation. Steady-state and time resolved fluorescence measurements indicate predominantly static quenching of t...

A model for studying polar-pi interactions between arenes spaced at van der Waals distances is developed on the basis of peri-diarylbiphenylenes. A set of 1,8-diarylbiphenylenes is synthesized comprising two Hammett series, one with reference to mesityl ring interactions and the other with reference to pentafluorophenyl ring interactions. X-Ray crystal structures of several derivatives are dete...

Antioxidants are made for the struggle and reconstruction of the damaged cells, because of their ability in destroying the free radicals. On account of their importance, a theoretical procedure was applied for the study of the molecular structure and radical scavenging activity of six hydroxyphenols which have been introduced as antioxidant compounds. All geometry structures were optimized by M...

In this investigation, the interaction of C20 and Si2H2 molecules was explored in the M06-2X/6-311++G(d,p)level of theory in gas solution phases. The obtained interaction energy values with standard method werecorrected by basis set superposition error (BSSE) during the geometry optimization for all molecules atthe same level of theory. Also, the bonding interaction between th...

Electronic structure calculations have been used for the effective triage of substituent effects on difluorinated vinylcyclopropane precursors and their ability to undergo vinyl cyclopropane rearrangements (VCPR). Groups which effectively stabilised radicals, specifically heteroarenes, were found to result in the lowest energy barriers. Ten novel precursors were synthesised to test the accuracy...

Amidines are special nitrogen analogues of the carboxylic acid, containing two N of different functionality. One is formally single bonded like-amino nitrogen (N) and the other is a formally double-bonded imino nitrogen (N), where protonation occurs first. The pKa’s of amidines vary from neutral to slightly acidic (pKa ranges from 4.4 to 14) depending on their substitution pattern. Amidines are...