نتایج جستجو برای: resonance assisted hydrogen bond

تعداد نتایج: 535876  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان 1390

abstract the influence of cation?? and anion?? interactions on the strength and nature of n…h hydrogen bond has been investigated by quantum chemical calculations in s-triazine…3hf complex. ab initio calculations were performed at mp2/6-311++g(d,p) level of theory. the natural bond orbital (nbo) analysis and the bader’s quantum theory of atoms in molecules (aim) were also used to elucidate t...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2010
ali heydar pakiari maryam farrokhnia

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, ...

Ali Heydar Pakiari, Maryam Farrokhnia

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...

2004
Sharan Shetty Dilip G. Kanhere Annick Goursot

We have performed ab initio molecular dynamics simulations to study the nature of the synchronous double proton transfer in formic acid dimer. In order to understand the evolution of the bonding during the double proton transfer, we have used the electron localization function and the molecular orbital isosurfaces. During the dynamics of the double proton transfer in formic acid dimer the two f...

Journal: :Chemical communications 2012
Xin Su Märt Lõkov Agnes Kütt Ivo Leito Ivan Aprahamian

A "V"-shaped Hammett plot shows that resonance-assisted hydrogen bonding does not dictate the strength of the intramolecular hydrogen bond in the E isomers of hydrazone-based switches because it involves an aromatic pyridyl ring.

2011
Carlos Bustos Luis Alvarez-Thon Juan-Guillermo Cárcamo Maria Teresa Garland Christian Sánchez

The conformation of the title mol-ecule, C(21)H(15)BrN(2)O(2), is stabilized by a weak intra-molecular C-H⋯N hydrogen bond and a strong resonance-assisted N-H⋯O intra-molecular hydrogen bond. In the crystal, the mol-ecules are linked by weak inter-molecular C-H⋯O inter-actions, forming zigzag chains along the b axis.

Journal: :Journal of computational chemistry 2007
John Frederick Beck Yirong Mo

Block-localized wave function (BLW) method, which is a variant of the ab initio valence bond (VB) theory, was employed to explore the nature of resonance-assisted hydrogen bonds (RAHBs) and to investigate the mechanism of synergistic interplay between pi delocalization and hydrogen-bonding interactions. We examined the dimers of formic acid, formamide, 4-pyrimidinone, 2-pyridinone, 2-hydroxpyri...

Journal: :Acta Crystallographica Section A Foundations of Crystallography 1993

Journal: :Acta crystallographica Section B, Structural science, crystal engineering and materials 2013
Magdalena Małecka Swastik Mondal Sander van Smaalen Carsten Paulmann

A combined experimental and theoretical study of one oxaphosphinane derivative was made on the basis of a topological analysis of its electron density distributions. The electron density was determined from a high-resolution X-ray diffraction data set measured with synchrotron radiation at 100 K, whereas theoretical calculations were performed using density functional theory (DFT) methods at th...

The quantum chemical calculations were performed to investigate the interplay between the anion˗π and intramolecular hydrogen bond (IMHB) interactions in the various complexes of 1,3,5-triamino-2,4,6-trinitrobenzene (ANB) with Hˉ, Fˉ, Clˉ and Brˉ anions. For better understanding the cooperative effects, the parent molecules (ANB) and the corresponding complexes of 1,3,5˗trinitrobenzene with the...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید