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...

Li(+) and Ca(2+) binding to the carbonyl oxygen sites of a model peptide system has been studied by (17)O solid-state NMR spectroscopy. (17)O chemical shift (CS) and quadrupole coupling (QC) tensors are determined in four Gly-(Gly-(17)O)-Gly polymorphs by a combination of stationary and fast magic-angle spinning (MAS) methods at high magnetic field, 19.6 T. In the crystal lattice, the carbonyl ...

We present a study of microphase separation induced by competitive hydrogen bonding in A-b-B/C diblock copolymer/homopolymer complexes where the diblock copolymer A-b-B is immiscible and the homopolymer C can interact unequally with both A and B blocks through hydrogen bonding. A model system containing poly(2-vinyl pyridine)-block-poly(methyl methacrylate) (P2VP-b-PMMA) and poly(4-vinyl phenol...

An energy decomposition analysis (EDA) method is proposed to isolate physically relevant components of the total intermolecular interaction energies such as the contribution from interacting frozen monomer densities, the energy lowering due to polarization of the densities, and the further energy lowering due to charge-transfer effects. This method is conceptually similar to existing EDA method...

Diphenyl(2-hydroxy-phenyl)phosphine was introduced as a ligand for gold(I) halides and pentafluorophenyl gold(I) in order to probe the interplay of intraand intermolecular interactions based on aurophilic (Au Au) and hydrogen bonding. 1:1 complexes of the type Ph2(2-HOC6H4)P-Au-X with X = Cl, Br, C6F5 have been prepared and characterized by analytical and spectroscopic data. The crystal structu...

We have evaluated the performance of a set of widely used force fields by calculating the geometries and stabilization energies for a large collection of intermolecular complexes. These complexes are representative of a range of chemical and biological systems for which hydrogen bonding, electrostatic, and van der Waals interactions play important roles. Benchmark energies are taken from the hi...

Transmission infrared spectroscopy has been used in a systematic laboratory study to investigate hydrogen bonding in binary mixtures of CH3OH and H2O, vapour deposited at 30 K, as a function of CH3OH/H2O mixing ratio, R. Strong intermolecular interactions are evident between CH3OH and H2O with infrared band profiles of the binary ices differing from that of the pure components and changing sign...

The stability of self-assembling cyclic peptides (CPs) is attained by the intermolecular backbone-backbone hydrogen bonding (H-bonding) interactions. In addition to this Hbonding interaction, the self-assembled CPs are further stabilized by various intermolecular side chain-side chain interactions. This study investigates the role of amino acids on the structure and stability of self-assembled ...

Crystalline N-alkyl-N-arylthioureas with ortho hydroxyl and para or meta methyl substituents to the phenyl ring were studied by single crystal X-ray diffraction, IR and solid state C CP MAS NMR. Two different modes of association were found: i) intermolecular NH...S bonds and NH not involved in hydrogen bonding in N-methyl-N(2-hydroxy,5-methylphenyl)thiourea 1, ii) cyclic dimers with two NH...S...