Improved Hydrogen Bonding at the NDDO-Type Semiempirical Quantum Mechanical/Molecular Mechanical Interface

2009 ◽  
Vol 5 (9) ◽  
pp. 2206-2211 ◽  
Author(s):  
Qiantao Wang ◽  
Richard A. Bryce
Keyword(s):  
Hydrogen Bonding ◽  
Quantum Mechanical ◽  
Mechanical Interface

Electrostatic Potential at Nuclei

2014 ◽  
pp. 87-122
Author(s):  
Sonia Ilieva ◽  
Boris Galabov
Keyword(s):  
Hydrogen Bonding ◽  
Kinetic Parameters ◽  
Organic Compounds ◽  
Electrostatic Potential ◽  
Original Work ◽  
Computational Approach ◽  
Reactivity Index ◽  
Quantum Mechanical ◽  
Mechanical Quantity ◽  
Substituent Constants

The chapter surveys mostly original work of the authors on the application of the electrostatic potential at nuclei (EPN) as a reactivity index in quantifying hydrogen bonding as well as different reactions of organic compounds. The EPN index was defined and introduced by E. B. Wilson (1962). However, it was first applied as a reactivity index much later in works from our laboratory (Bobadova-Parvanova & Galabov, 1998; Galabov & Bobadova-Parvanova, 1999; Dimitrova, Ilieva, & Galabov, 2002; Cheshmedzhieva, Ilieva, Hadjieva, Trayanova, & Galabov, 2009; Galabov, Cheshmedzhieva, Ilieva, & Hadjieva, 2004; Galabov, Ileiva, & Schaefer, 2006; Galabov, Nikolova, Wilke, Schaefer, & Allen, 2008; Galabov, Ilieva, Hadjieva, Atanasov, & Schaefer, 2008; Koleva, Galabov, Wu, Schaefer, & Schleyer, 2009). Numerous applications showed that the EPN index, an accurate quantum mechanical quantity, predicts with remarkable accuracy the energy shifts accompanying hydrogen bonding. The theoretically evaluated EPN descriptor correlates also excellently with experimental and theoretically evaluated kinetic parameters for a number of important organic reactions. Based on these findings an efficient computational approach for the evaluation of substituent constants was developed.

Electrostatic Potential at Nuclei

2011 ◽  
pp. 280-317
Author(s):  
Sonia Ilieva ◽  
Boris Galabov
Keyword(s):  
Hydrogen Bonding ◽  
Kinetic Parameters ◽  
Electrostatic Potential ◽  
Computational Approach ◽  
Organic Reactions ◽  
Quantum Mechanical ◽  
Mechanical Quantity ◽  
Substituent Constants

Numerous applications showed that the EPN index, an accurate quantum mechanical quantity, predicts with remarkable accuracy the energy shifts accompanying hydrogen bonding. The theoretically evaluated EPN descriptor correlates also excellently with experimental and theoretically evaluated kinetic parameters for a number of important organic reactions. Based on these findings an efficient computational approach for the evaluation of substituent constants was developed.

scholarly journals Simulating Absorption Spectra of Flavonoids in Aqueous Solution: A Polarizable QM/MM Study

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5853
Author(s):  
Sulejman Skoko ◽  
Matteo Ambrosetti ◽  
Tommaso Giovannini ◽  
Chiara Cappelli
Keyword(s):  
Molecular Dynamics ◽  
Aqueous Solution ◽  
Hydrogen Bonding ◽  
Force Field ◽  
Absorption Spectra ◽  
Computational Study ◽  
Md Simulations ◽  
Quantum Mechanical ◽  
Hydrogen Bonding Interactions

We present a detailed computational study of the UV/Vis spectra of four relevant flavonoids in aqueous solution, namely luteolin, kaempferol, quercetin, and myricetin. The absorption spectra are simulated by exploiting a fully polarizable quantum mechanical (QM)/molecular mechanics (MM) model, based on the fluctuating charge (FQ) force field. Such a model is coupled with configurational sampling obtained by performing classical molecular dynamics (MD) simulations. The calculated QM/FQ spectra are compared with the experiments. We show that an accurate reproduction of the UV/Vis spectra of the selected flavonoids can be obtained by appropriately taking into account the role of configurational sampling, polarization, and hydrogen bonding interactions.

scholarly journals Intramolecular hydrogen bonding and conformational preferences on 2-fluoro-phenylaminocyclohexanol

2018 ◽  
Author(s):  
Cassia Chiari ◽  
Claudio Francisco Tormena ◽  
Kahlil Schwanka Salome ◽  
Laiza Bruzadelle Loureiro ◽  
Renan Vidal Viesser
Keyword(s):  
Hydrogen Bonding ◽  
Driving Force ◽  
Conformational Stability ◽  
Intramolecular Hydrogen Bonding ◽  
Quantum Mechanical ◽  
Resonance Spectroscopy ◽  
Quantum Mechanical Calculations ◽  
Conformational Preferences ◽  
Intramolecular Hydrogen ◽  
Theoretical Results

The aim of this study is to evaluate the influence and strength of possible intramolecular hydrogen bonding (IntraHB) involving N-H--O, O-H--N, O-H--F and N-H--F molecular moieties as a driving force on the conformational preferences of 2-fluoro-phenylaminocyclohexanol. To achieve our purpose we synthesized the compound and performed it's characterization using Nuclear Magnetic Resonance Spectroscopy (NMR). Quantum mechanical calculations were carried out to evaluate the effect of IntraHB on the conformational stability. Experimental and theoretical results showed that N-H--F and O-H--N IntraHB have a greater influence on the conformacional preferably adopted by the molecule.

Modulation of quantum mechanical exchange couplings in transition metal hydrides rough hydrogen bonding

1997 ◽  
Vol 259 (1-2) ◽  
pp. 1-4 ◽  
Author(s):  
JoséA. Ayllon ◽  
Sylviane Sabo-Etienne ◽  
Bruno Chaudret ◽  
Stefan Ulrich ◽  
Hans-Heinrich Limbach
Keyword(s):  
Hydrogen Bonding ◽  
Transition Metal ◽  
Metal Hydrides ◽  
Quantum Mechanical ◽  
Transition Metal Hydrides
Sign in / Sign up

Export Citation Format

Share Document