نتایج جستجو برای: non hydrogen bonded interaction

تعداد نتایج: 1958437  

2016
Ibon Alkorta Janet E. Del Bene Jose Elguero

A search of the Cambridge Structural Database (CSD) was carried out for phosphine-water and arsine-water complexes in which water is either the proton donor in hydrogen-bonded complexes, or the electron-pair donor in pnicogen-bonded complexes. The range of experimental P-O distances in the phosphine complexes is consistent with the results of ab initio MP2/aug’-cc-pVTZ calculations carried out ...

Journal: :Computer Physics Communications 2005
Christoph Dellago Mor M. Naor

We use ab initio molecular dynamics simulation to calculate the dipole moment of water molecules in one-dimensional hydrogen bonded chains in narrow pores. The electronic charges are partitioned among the water molecules using maximally localized Wannier functions. For water molecules confined to the interior of a carbon nanotube we find an average dipole moment of about 2.7 D, almost 10 % lowe...

Journal: :The Journal of organic chemistry 2012
Borys Ośmiałowski Erkki Kolehmainen Magdalena Kowalska

2-Acylamino-6-pyridones (acyl = RCO, where R = Me, Et, i-Pr, t-Bu, and 1-adamantyl) were previously characterized by X-ray diffractometry and solid-state NMR techniques by us. One of these compounds was used recently in organocatalysis. The series is now studied in solution and by computational methods recommended for noncovalent interactions (DFT/M05). These compounds showed interesting behavi...

Journal: :Chemical communications 2010
Duygu Deniz Günbaş Leszek Zalewski Albert M Brouwer

In rotaxane 1, two co-conformations are populated in CDCl(3) at temperatures between 250 and 330 K. The thermodynamic parameters show strong enthalpy-entropy compensation, and a non-negligible heat capacity difference between the two forms.

2002
Ivelina Georgieva Daniel Binev Natasha Trendafilova unther Bauer

DFT study of hydrogen-bonded dimers and tetramer of glyoxilic acid oxime (GAO) has been performed at B3LYP/ 6-31G* and B3LYP/6-31++G** levels of the theory. The N HAO and O HAO hydrogen bondings in the selfassembling structures studied have been estimated from intermolecular distances, enthalpy of stabilization, hydrogenbonding energies and AIM electron density at the hydrogen bond critical poi...

2006
ARUNDHATI KOTWAL V. KOTHEKAR

The conformation of the α3 helix of Cro protein (residues 27–36) of bacteriophage λ is optimised by the damped least square minimization technique, with the steric constraint that Cα atom positions should match the crystallographic data available to date. On the basis of minimization of total interaction and conformation energy, models for complexes of this peptide sequence with heptanucleotide...

Journal: :journal of physical & theoretical chemistry 2010
s. shojaee f. naderi h. yamoula m. monajjemi

we optimized the geometries of the graphene and graphene with hydrogen using pw91vwn, pwcipl,mpwlyp, g96lyp, g96141.0-210.6-310, 6-31g*ievels of theory and compared our results with each other.we present the most important structural parameters determined for the addition of a hydrogen atom tographene and the outward movement of the carbon atom that is bonded to hydrogen is 0.48 a also wecalcul...

2013
Anwesa Karmakar Jyoti Roy Choudhuri Vivek K. Yadav Bhabani S. Mallik Amalendu Chandra

A theoretical study of vibrational spectral diffusion in aqueous NaBr solutions is presented by means of ab initio molecular dynamics simulations and time series analysis. The OD stretch frequencies of deuterated water hydrogen bonded to the bromide ions are found to be higher than those in the bulk which implies a somewhat weaker Br–water hydrogen bonds than those between water molecules. The ...

Journal: :Journal of the American Chemical Society 2011
Wei-Hong Chen Wei-Tsung Chuang U-Ser Jeng Hwo-Shuenn Sheu Hong-Cheu Lin

In this study, we synthesized three analogous bent-core molecules, a hydrogen-bonded complex and a covalent-bonded compound with branched siloxane units (H-SiO and C-SiO, respectively) and a hydrogen-bonded complex with an alkyl unit (H-Alk), and investigated the effects of the hydrogen bonding and branched siloxane terminal units on their mesomorphic properties. The covalent-bonded compound C-...

Journal: :Organic & biomolecular chemistry 2011
Amal Kumar Mandal Moorthy Suresh Amitava Das

A new host molecule, having two azacrown derivatives bridged by luminescent naphthalene diimide functionality, is found to form a [3]pseudorotaxane derivative with imidazolim ion-based guest molecules in non-polar solvents through hydrogen-bonded adduct formation. Depending upon the length of the covalent linker that links the imidazolium ion and the luminescent naphthalene fragment in the gues...

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