scholarly journals A probe of steric ligand substituent effects on the spin crossover of Fe(ii) complexes

2017 ◽  
Vol 4 (8) ◽  
pp. 1374-1383 ◽  
Author(s):  
C. Bartual-Murgui ◽  
S. Vela ◽  
M. Darawsheh ◽  
R. Diego ◽  
S. J. Teat ◽  
...  
Keyword(s):  
Spin Crossover ◽  
Substituent Effects ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Ligand substituents modulate the SCO temperature of Fe(ii) complexes through intramolecular non-covalent interactions.

Substituent Effects on Non-Covalent Interactions with Aromatic Rings: Insights from Computational Chemistry

ChemPhysChem ◽  
2011 ◽  
Vol 12 (17) ◽  
pp. 3116-3130 ◽  
Author(s):  
Rajesh K. Raju ◽  
Jacob W. G. Bloom ◽  
Yi An ◽  
Steven E. Wheeler
Keyword(s):  
Computational Chemistry ◽  
Substituent Effects ◽  
Aromatic Rings ◽  
Non Covalent Interactions ◽  
Covalent Interactions

scholarly journals Rotational Spectroscopy Meets Quantum Chemistry for Analyzing Substituent Effects on Non-Covalent Interactions: The Case of the Trifluoroacetophenone-Water Complex

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4899
Author(s):  
Juncheng Lei ◽  
Silvia Alessandrini ◽  
Junhua Chen ◽  
Yang Zheng ◽  
Lorenzo Spada ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Substituent Effects ◽  
Equilibrium Structure ◽  
Proton Donor ◽  
Rotational Spectroscopy ◽  
Donor And Acceptor ◽  
Analogous Complex ◽  
Non Covalent Interactions ◽  
Covalent Interactions

The most stable isomer of the 1:1 complex formed by 2,2,2-trifluoroacetophenone and water has been characterized by combining rotational spectroscopy in supersonic expansion and state-of-the-art quantum-chemical computations. In the observed isomer, water plays the double role of proton donor and acceptor, thus forming a seven-membered ring with 2,2,2-trifluoroacetophenone. Accurate intermolecular parameters featuring one classical O-H···O hydrogen bond and one weak C-H···O hydrogen bond have been determined by means of a semi-experimental approach for equilibrium structure. Furthermore, insights on the nature of the established non-covalent interactions have been unveiled by means of different bond analyses. The comparison with the analogous complex formed by acetophenone with water points out the remarkable role played by fluorine atoms in tuning non-covalent interactions.

scholarly journals Symmetry-Adapted Perturbation Theory Decomposition of the Reaction Force: Insights into Substituent Effects Involved in Hemiacetal Formation Mechanisms

2019 ◽  
Author(s):  
Wallace Derricotte
Keyword(s):  
Perturbation Theory ◽  
Functional Group ◽  
Reaction Force ◽  
Substituent Effects ◽  
Formation Mechanisms ◽  
Lower Activation ◽  
Non Covalent Interactions ◽  
Force Components ◽  
Covalent Interactions ◽  
Lower Activation Energy

<div>The decomposition of the reaction force based on symmetry-adapted perturbation theory (SAPT) has been proposed. This approach was used to investigate the subtituent effects along the reaction coordinate pathway for the hemiacetal formation mechanism between methanol and substituted aldehydes of the form CX<sub>3</sub>CHO (X = H, F, Cl, and Br), providing a quantitative evaluation of the reaction-driving and reaction-retarding force components. Our results highlight the importance of more favorable electrostatic and induction effects in the reactions involving halogenated aldehydes that leads to lower activation energy barriers. These substituent effects are further elucidated by applying the functional-group partition of symmetry-adapted</div><div>perturbation theory (F-SAPT). The results show that the reaction is largely driven by favorable direct non-covalent interactions between the CX<sub>3</sub> group on the aldehyde and the OH group on methanol.</div>

scholarly journals Substituent Effects That Control Conjugated Oligomer Conformation through Non-covalent Interactions

2017 ◽  
Vol 139 (14) ◽  
pp. 5164-5174 ◽  
Author(s):  
Seth A. Sharber ◽  
Rom Nath Baral ◽  
Fanny Frausto ◽  
Terry E. Haas ◽  
Peter Müller ◽  
...  
Keyword(s):  
Substituent Effects ◽  
Non Covalent Interactions ◽  
Covalent Interactions

scholarly journals Symmetry-Adapted Perturbation Theory Decomposition of the Reaction Force: Insights into Substituent Effects Involved in Hemiacetal Formation Mechanisms

2019 ◽  
Author(s):  
Wallace Derricotte
Keyword(s):  
Perturbation Theory ◽  
Functional Group ◽  
Reaction Force ◽  
Substituent Effects ◽  
Formation Mechanisms ◽  
Lower Activation ◽  
Non Covalent Interactions ◽  
Force Components ◽  
Covalent Interactions ◽  
Lower Activation Energy

<div>The decomposition of the reaction force based on symmetry-adapted perturbation theory (SAPT) has been proposed. This approach was used to investigate the subtituent effects along the reaction coordinate pathway for the hemiacetal formation mechanism between methanol and substituted aldehydes of the form CX<sub>3</sub>CHO (X = H, F, Cl, and Br), providing a quantitative evaluation of the reaction-driving and reaction-retarding force components. Our results highlight the importance of more favorable electrostatic and induction effects in the reactions involving halogenated aldehydes that leads to lower activation energy barriers. These substituent effects are further elucidated by applying the functional-group partition of symmetry-adapted</div><div>perturbation theory (F-SAPT). The results show that the reaction is largely driven by favorable direct non-covalent interactions between the CX<sub>3</sub> group on the aldehyde and the OH group on methanol.</div>

NON COVALENT INTERACTIONS IN LARGE DIAMONDOID DIMERS IN THE GAS PHASE - A MICROWAVE STUDY

2017 ◽  
Author(s):  
Cristobal Perez ◽  
Melanie Schnell ◽  
Peter Schreiner ◽  
Norbert Mitzel ◽  
Yury Vishnevskiy ◽  
...  
Keyword(s):  
Gas Phase ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Vapour Pressure Isotope Effect on Evaporation from Pure Organic Phases - a PIMD Approach

2020 ◽  
Author(s):  
Luis Vasquez ◽  
Agnieszka Dybala-Defratyka
Keyword(s):  
Path Integral ◽  
Vapour Pressure ◽  
Density Functional ◽  
Isotope Effects ◽  
Tight Binding ◽  
Decomposition Analysis ◽  
Energy Decomposition Analysis ◽  
Special Importance ◽  
Non Covalent Interactions ◽  
Covalent Interactions

<p></p><p>Very often in order to understand physical and chemical processes taking place among several phases fractionation of naturally abundant isotopes is monitored. Its measurement can be accompanied by theoretical determination to provide a more insightful interpretation of observed phenomena. Predictions are challenging due to the complexity of the effects involved in fractionation such as solvent effects and non-covalent interactions governing the behavior of the system which results in the necessity of using large models of those systems. This is sometimes a bottleneck and limits the theoretical description to only a few methods.<br> In this work vapour pressure isotope effects on evaporation from various organic solvents (ethanol, bromobenzene, dibromomethane, and trichloromethane) in the pure phase are estimated by combining force field or self-consistent charge density-functional tight-binding (SCC-DFTB) atomistic simulations with path integral principle. Furthermore, the recently developed Suzuki-Chin path integral is tested. In general, isotope effects are predicted qualitatively for most of the cases, however, the distinction between position-specific isotope effects observed for ethanol was only reproduced by SCC-DFTB, which indicates the importance of using non-harmonic bond approximations.<br> Energy decomposition analysis performed using the symmetry-adapted perturbation theory (SAPT) revealed sometimes quite substantial differences in interaction energy depending on whether the studied system was treated classically or quantum mechanically. Those observed differences might be the source of different magnitudes of isotope effects predicted using these two different levels of theory which is of special importance for the systems governed by non-covalent interactions.</p><br><p></p>

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