dft-gga method of perdew-burke-ernzerhof (pbe) is used with aug-cc-pvtz, 6-311++g**, and def2-tzvp large basis sets to study the hydrogen bond interactions between oxygen lone pair as a donor electron with hydrogen atom connected to the aniline’s nitrogen as an electron acceptor (h2o···hnh-ph), and nitrogen lone pair with hydrogen of water molecule (ph-h2n···hoh), both in the gas phase. in some...

The spatial volume occupied by an atom depends on its electronic density. Although this density can only be evaluated exactly for hydrogen-like atoms, there are many excellent algorithms and packages to calculate it numerically for other materials. Three-dimensional visualization of charge density is challenging, especially when several molecular/atomic levels are intertwined in space. In this ...

bioactive food components (such as phenolic compounds, carotenoids, anthocyanins, tochopherols, ascorbic acid, flavonoids, minerals, enzymes and pectin) are active ingredients in food or dietary supplements, which proven to have an important role in health, and are safe for human consumption. these compounds exert their antioxidant effects by different mechanisms such as single electron transfe...

where H-H-C and H-D-C are weak bonds and make a negligible contribution, leads to a value of -2 kcal. Therefore, E5-E2=1 kcal compared with the experimental value of 1.0 kcal. The preexponential factor for this pair of isotopic reactions can be calculated from the difference in the entropies of activation. Using the same loose complex as above and applying the expression derived by Bigeleisens ...

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...