The mechanism of the intramolecular Diels–Alder (IMDA) reaction of benzoquinone 1, in the absence and in the presence of three water molecules, 1w, has been studied by means of density functional theory (DFT) methods, using the M05-2X and B3LYP functionals for exploration of the potential energy surface (PES). The energy and geometrical results obtained are complemented with a population ...

Under the QSPR/QSAR paradigm, a comparative study is made of the known drug activity of as many as 15 anti-tubercular drugs vis-à-vis the computed quantum mechanical global reactivity descriptors like global hardness, global softness and global electrophilicity index. The comparative study reveals that the experimentally determined activity of drug molecules, including its variation with side s...

An HPLC assay is described that can be used to study the covalent bonding interaction of carbinolamine-containing pyrrolo[2,1-c][1,4]benzodiazepines with the model nucleophile thiophenol, in order to evaluate electrophilicity at the C-11-position. Preliminary experiments with anthramycin, tomaymycin and neothramycin show that their reaction with thiophenol follows second-order kinetics, but the...

A series of homo- and hetero-tri(aryl)boranes incorporating pentafluorophenyl, 3,5-bis(trifluoromethyl)phenyl, and pentachlorophenyl groups, four of which are novel species, have been studied as the acidic component of frustrated Lewis pairs for the heterolytic cleavage of H2. Under mild conditions eight of these will cleave H2; the rate of cleavage depending on both the electrophilicity of the...

Acetalization of benzaldehyde and substituted benzaldehydes (containing both electron-donating and electron-withdrawing groups) is explained qualitatively on the basis of global electrophilicity descriptor, w, as proposed by Parr and coworkers. The generated values of w can explain qualitatively the preferential electrophilic addition, and hence, the yield of acetalization obtained in an earlie...

chemical hardness (), absolute electronegativity (), and electrophilicity () have importantapplications in inorganic chemistry. these concepts are defined quantitatively as � � �� � ����,� � �� � ����, � � ������where i is the ionization energy and a is the electron affinity. in thisstudy, graphical method was used to see the relation of electron configuration with chemicalhardness, absolute...

in this research at the first, captopril drug (ca) and its fullerene connected form (fca) wereoptimized. natural bond orbital (nbo) calculations for these compounds were carried out at theb3lyp/6-31g quantum chemistry level, in the gas phase and the liquid phase. these calculations canbe performed at different accuracy levels depending on the aim of the theoretical study [1]. forinstance, densi...

The size-dependence of different local reactivity descriptors of dimer A2 and AB type of systems is discussed. We derive analytic results of these descriptors calculated using finite difference approximation. In particular, we studied Fukui functions, relative electrophilicity and relative nucleophilicity, local softness and local philicity. The results are explained using the example of the di...