the effect of interactions of various ia and iia cations with two positions of the adenine-thymine (a−t) and guanine-cytosine (g−c) base pairs on the geometries and individual hydrogen bond (hb) energies have been investigated by using the atoms in molecules (aim) method at the b3lyp/6-311++g(d,p) level of theory. the cations that possess higher charge/radius (q/rad) ratio make higher changes o...

the interaction of dppa which is an important component in cellular membrane with molecules of water asmedia, cause some changes in geometry of dppa .in this study we focused our attention on comparing thismolecule with related hydrated complexes employing different basis sets at hartree-fock levels of theory. thetheoretical nmr shielding tensor of some imported atoms were also reported.

In the present work, the sensitivity to the moisture (hygroscopisity) is studied for 3,4-dinitropyrazole (DNP) as a famous energetic molecule. All of the DNP-H2O complex systems (1-3) as well as individual molecules were optimized and bond lengths, bond angles, dihedral angles, charge transfer and stability via NBO analysis, corrected interaction energies with ZPE + BSSE and hydrogen bonds anal...

the concept of resonance assisted hydrogen bond (rahb), which usually occurs in b diketons, has a remarkable role in chemistry. these molecules, which contain heteroatom particularly o and n, are species with biological interest in protein folding and dna pairing. therefore, the amplification of hydrogen bonds strength by substituents may be important in life sciences. in the current research, ...

the one-dimensional model of lippincott and schroeder for hydrogen bond has been re-examined and it has been shown that o-h bond distance depends on repulsive van der waals and attractive electrostatic potentials.it has been shown that constant b in the van der waals repulsion potential is not transferable to all hydrogen bonds. the possibility of obtaining the semi-empircal parameters in the l...

The concept of Resonance Assisted Hydrogen Bond (RAHB), which usually occurs in b diketons, has a remarkable role in chemistry. These molecules, which contain heteroatom particularly O and N, are species with biological interest in protein folding and DNA pairing. Therefore, the amplification of hydrogen bonds strength by substituents may be important in life scie...

The one-dimensional model of Lippincott and Schroeder for hydrogen bond has Been re-examined and it has been shown that O-H bond distance depends on repulsive van der Waals and attractive electrostatic potentials.it has been shown that constant b in the van der Waals repulsion potential is not transferable to all hydrogen bonds. The possibility of obtaining the semi-empircal parameters i...

The effect of interactions of various Ia and IIa cations with two positions of the adenine-thymine (A−T) and guanine-cytosine (G−C) base pairs on the geometries and individual hydrogen bond (HB) energies have been investigated by using the atoms in molecules (AIM) method at the B3LYP/6-311++G(d,p) level of theory. The cations that possess higher charge/radius (q/rad) ratio make higher changes o...

a theoretical density functional theory (dft) study was performed on a series of the neutral n-phenylthiourea substituents (p-oc2h5, p-ch3, m-ch3, h, p-cl, p-br, m-cl, and p-no2) as the sensor of acetate and fluoride anions. the hydrogen bond character was analyzed as a scale of the sensing activity. it was confirmed that hydrogen bond between the p-no2 derivatives of n-phenylthiourea and fluor...