hydrogen bonding of dppe with water that surrounded of membrane, plays an important role in permeability ofmembrane that we were presented this matter with analysis of bond angles and torsion angles before and after ofadded water molecules.interaction with water molecules causes some changes in the geometry of dppe which were explained bythe contribution of zwitterionic form of dppe molecule, a...

density functional (dft) calculations at m05-2x/aug-cc-pvdz level were used to analyze the interactions between dimethyl sulfoxide (dmso) dimers. the structures obtained have been analyzed with the atoms in molecules (aims) and natural bond orbital (nbo) methodologies. four minima were located on the potential energy surface of the dimers. three types of interactions are observed, ch•••o, ch•••...

we present detailed theoretical studies of the h-bonded complexes formed from interaction between 5-fluorouracil and various six-membered cyclic nitrosamine compounds. in this study, an investigation on intermolecular interactions in x-nu (x = ch2, sih2,bh, alh, nh, ph, o and s) complexes is carried out using density functional theory. the calculations are conducted on b3lyp/6-311++‏‏g** level ...

enaminones are those structures made up three various functional groups including carbonyl, alkeneand amine groups which arelocated along with each other in a conjugate fashion. these compoundsare of much attention due to special characteristics and numerous applications. in the paper, sixvarious enaminone structures were theoretically optimized and after concluding, were compared withequivalen...

in the present work, an extensive theoretical calculation study on histidine-histidine dipeptide in gas phase is done by using dft method with gaussian 98 program. through investigations on the molecular geometries of this molecule it is found that there is six rings in the molecules not two rings. the presence of four intramolecular hydrogen bonds is responsible for the formation of additional...

molecules to evolve in the test tube. With the discovery of catalytic RNA, and advances in nucleic acid amplification techniques such as the polymerase chain reaction, it became possible to construct laboratory systems that allow the Darwinian evolution of functional RNA (and later DNA) molecules. This is not evolution based on natural selection, but rather directed evolution based on selection...

an azobenzene bridge was introduced into the lower (or smaller) rim of p-tert-butylcalix[8]arene to form 1,5-singly bridged calix[8]arene derivatives, respectively. bridged calix[8]arene of conformationally rigid wereisolated. the stability of the two structures of bridged calix[8]arenes have been compared.the study of organicstructure to form nanoporous structures is a well known in chemistry ...