How to estimate the intramolecular hydrogen-bond energy of complex RAHB systems? A theoretical study

Nowroozi, Alireza; Hajiabadi, H.

doi:10.1007/s11224-013-0253-x

Cited by 11 publications

(9 citation statements)

References 27 publications

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“…With the confirmation of the RIHB concept in the ionic system 1 , we continued to study a neutral system, namely ( z )‐3‐imino‐1‐propen‐1‐ol, a tautomer of β‐aminoacrolein which has three different stereoisomers ( 2 – 4 ) with different intramolecular H‐bonds. Isomers 2 and 3 contain H‐bonds of the NH⋅⋅⋅O type while 4 has a N⋅⋅⋅HO H‐bond, but in all three isomers H‐bonds are coupled with π‐resonance . The major results are shown in Table and Figure .…”

Section: Methodsmentioning

confidence: 97%

A Direct Proof of the Resonance‐Impaired Hydrogen Bond (RIHB) Concept

Lin

2017

Chemistry A European J

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The concept of resonance-enhanced hydrogen bond (RAHB) has been widely accepted and applied as it highlights the positive impact of π-conjugation on intramolecular H-bonds. However, electron delocalization is directional and there is a possibility that π-resonance goes from the H-bond acceptor to the H-bond donor, leading to a negative impact on H-bonds. Here we used the block-localized wavefunction (BLW) method which is a variant of ab initio valence bond (VB) theory and able to derive strictly electron-localized structures self-consistently, to quantify the interplay between H-bond and π-resonance in the terms of geometry, energetics and spectral properties. The comparison of geometrical optimizations with and without π-resonance shows that conjugation can indeed either enhance or weaken intramolecular H-bonds. We further experimented with various substituents attached to either the H-bond acceptor and/or H-bond donor side(s) to tune the H-bonding strength in both directions.

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Section: Methodsmentioning

confidence: 97%

A Direct Proof of the Resonance‐Impaired Hydrogen Bond (RIHB) Concept

Lin

2017

Chemistry A European J

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“…[1][2][3][4][5][6][7][8] Despite extensive research on the topic, it has been a centre of attraction for further studies as the perception changed from purely electrostatic to partially covalent, [9][10][11] from conventional polar to nonconventional hydrogen bond (HB) donors, [12][13][14][15][16][17] from electronegative lone pair bearing HB acceptors to pi cloud as HB acceptors. [18][19][20][21][22] They have been very well characterized by various methodologies including AIM [23][24][25] (atoms in molecules), NBO [26][27][28] (natural bond orbital), MESP [29][30][31][32] (molecular electrostatic potential), vibrational frequency analysis, [33][34][35] etc.…”

Section: Introductionmentioning

confidence: 99%

Theoretical Characterization of Hydrogen Bonding Interactions between RCHO (R = H, CN, CF3, OCH3, NH2) and HOR′(R′ = H, Cl, CH3, NH2, C(O)H, C6H5)

Kaur

2015

J Chem Sci

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In this work, density functional theory and ab initio molecular orbital calculations were used to investigate the hydrogen bonded complexes of type RCHO· · · HOR (R = H, CN, CF 3 , OCH 3 , NH 2 ; R = H, Cl, CH 3 , NH 2 , C(O)H, C 6 H 5 ) employing 6-31++g** and cc-pVTZ basis sets. Thus, the present work considers how the substituents at both the hydrogen bond donor and acceptor affect the hydrogen bond strength. From the analysis, it is reflected that presence of -OCH 3 and -NH 2 substituents at RCHO greatly strengthen the stabilization energies, while -CN and -CF 3 decrease the same with respect to HCHO as hydrogen bond acceptor. The highest stabilization results in case of (H 2 N)CHO as hydrogen bond acceptor. The variation of the substituents at -OH functional group also influences the strength of hydrogen bond; nearly all the substituents increase the stabilization energy relative to HOH. The analysis of geometrical parameters; proton affinities, charge transfer, electron delocalization studies have been carried out.

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“…Bifurcated H‐bonds have been measured by DFT calculations and isotope‐edited FTIR spectroscopy in transmembrane (influenza A M2 protein and Severe Acute Respiratory Syndrome coronavirus [SARS] E protein) or in complex RAHB environments . In a modern context, furcation includes all kinds of strong (O−H⋅⋅⋅⋅O, N−H⋅⋅⋅⋅O) and weak (C−H⋅⋅⋅⋅O) H‐bonds .…”

Section: Non Covalent Bonding Interactionsmentioning

confidence: 99%

H‐Bond: Τhe Chemistry‐Biology H‐Bridge

Pairas

Tsoungas

2016

ChemistrySelect

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H‐bonding, as a non covalent stabilizing interaction of diverse nature, has a central role in the structure, function and dynamics of chemical and biological processes, pivotal to molecular recognition and eventually to drug design. Types of conventional and non conventional (H−H, dihydrogen, H‐ π, CH‐ π, anti‐ , proton coordination and H−S) H‐bonding interactions are discussed as well as features emerging from their interplay, such as cooperativity (σ‐ and π‐) effects and allostery. Its utility in many applications is described. Catalysis, proton and electron transfer processes in various materials or supramolecular architectures of preorganized hosts for guest binding, are front‐line technology. The H‐bond–related concept of proton transfer (PT) addresses energy issues or deciphering the mechanism of many natural and synthetic processes. PT is also of paramount importance in the functions of cells and is assisted by large complex proteins embedded in membranes. Both intermolecular and intramolecular PT in H‐bonded systems has received attention, theoretically and experimentally, using prototype molecules. It is found in rearrangement reactions, protein functions, and enzyme reactions or across proton channels and pumps. Investigations on the competition between intra‐ and intermolecular H bonding are discussed. Of particular interest is the H‐bond furcation, a common phenomenon in protein‐ligand binding. Multiple H‐bonding (H‐bond furcation) is observed in supramolecular structures.

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How to estimate the intramolecular hydrogen-bond energy of complex RAHB systems? A theoretical study

Cited by 11 publications

References 27 publications

A Direct Proof of the Resonance‐Impaired Hydrogen Bond (RIHB) Concept

A Direct Proof of the Resonance‐Impaired Hydrogen Bond (RIHB) Concept

Theoretical Characterization of Hydrogen Bonding Interactions between RCHO (R = H, CN, CF3, OCH3, NH2) and HOR′(R′ = H, Cl, CH3, NH2, C(O)H, C6H5)

H‐Bond: Τhe Chemistry‐Biology H‐Bridge

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