Intermolecular Hydrogen Bond Involving a π-Base as the Proton Acceptor. I. Detection by the Refractive Index Method

1964 ◽  
Vol 68 (10) ◽  
pp. 2895-2898 ◽  
Author(s):  
Zen-ichi Yoshida ◽  
Eiji Osawa ◽  
Ryohei Oda
Keyword(s):  
Hydrogen Bond ◽  
Refractive Index ◽  
Intermolecular Hydrogen Bond ◽  
Proton Acceptor ◽  
Index Method

scholarly journals Theoretical insight to intermolecular hydrogen bond interactions between methyl N-(2-pyridyl) carbamate and acetic acid: substituent effects, cooperativity and energy decomposition analysis

2019 ◽  
Vol 51 (2) ◽  
pp. 224-233
Author(s):  
S. M. Chalanchi ◽  
A. Ebrahimi ◽  
A. Nowroozi
Keyword(s):  
Hydrogen Bond ◽  
Acetic Acid ◽  
Active Sites ◽  
Intermolecular Hydrogen Bond ◽  
Substituent Effects ◽  
Proton Acceptor ◽  
Orbital Energy ◽  
Energy Decomposition Analysis ◽  
Interaction Energies ◽  
Energy Decomposition

In the present work, the hydrogen bond (HB) interactions between substituted syn and anti rotamers of methyl N-(2-pyridyl) carbamate and acetic acid were investigated using quantum mechanical (QM) calculations. The rotamers have two typical active sites to form hydrogen bonds with acetic acid, such that four stable complexes are found on the potential energy surface. The complexes in which the oxygen atom of carbamate acts as proton acceptor are stabilized by EWSs and are destabilized by EDSs. The trend in the effects of substituents is reversed in the other two complexes, in which the nitrogen atom of ring is involved in the interaction. According to energy data, the substituent effects on the interaction energy can be expressed by Hammett constants. The natural resonance theory (NRT) model was used to investigate the charge distribution on the carbamate group and to discuss the interaction energies. The individual HB energies were estimated to evaluate their cooperative contributions on the interaction energies of the complexes. In addition, the localized molecular orbital energy decomposition analyses (LMO-EDA) demonstrate that the electrostatic interactions are the most important stabilizing components of interactions.

scholarly journals Density Functional Theory (DFT) and Natural Bond Orbital (NBO) Analysis of Intermolecular Hydrogen Bond Interaction in "Phosphorylated Nata De Coco - Water"

2018 ◽  
Vol 18 (1) ◽  
pp. 173 ◽  
Author(s):  
Sitti Rahmawati ◽  
Cynthia Linaya Radiman ◽  
Muhamad Abdulkadir Martoprawiro
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Charge Transfer ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
Intermolecular Hydrogen Bond ◽  
Lone Pair ◽  
Basis Set ◽  
Proton Acceptor ◽  
Functional Theory

This study aims to study the conformation, the hydrogen bond network, and the stabilities of all the possible intermolecular interactions in phosphorylated nata de coco membrane with water (NDCF-(H2O)n, n = 1-5). Analysis of natural bond orbital (NBO) was performed to measure the relative strength of the hydrogen bonding interactions, charge transfer, particularly the interactions of n-σ * O-H and to take into account the effect on the stabilities of the molecular structure. All calculation were performed using density functional theory (DFT) method, at B3LYP functional level of theory and 6-311 G** basis set. The charge transfer between the lone pair of a proton acceptor to the anti-bonding orbital of the proton donor provides the substantial to the stabilization of the hydrogen bonds. Interaction between NDCF and (H2O)5 was strongest with the stabilization energy of 37.73 kcal/mol, that indicate the ease of donating lone pair electrons. The contributions of each hydrogen bond to the stability of the complex have been analyzed.

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