scholarly journals Tetrel Bonding in CB11H11 Carbonium Ylide

2021 ◽  
Author(s):  
Maxime Ferrer ◽  
Ibon Alkorta ◽  
José Elguero ◽  
Josep M. Oliva-Enrich
Keyword(s):  
Lewis Acid ◽  
Quantum Chemical ◽  
Molecular Electrostatic Potential ◽  
Weak Interactions ◽  
Topological Analysis ◽  
Closed Shell ◽  
Lewis Bases ◽  
High Level ◽  
Quantum Chemical Computations ◽  
Vacant Orbital

High-level quantum-chemical computations (G4MP2) are carried out in the study of complexes featuring tetrel bonding between the carbon atom in the carbenoid CB11H11 - obtained by hydride removal in the C-H bond of the known closo-monocarbadodecaborate anion CB11H12() and acting as Lewis acid (LA) - and Lewis bases (LB) of different type; the electron donor groups in the tetrel bond feature carbon, nitrogen, oxygen, fluorine, silicon, phosphorus, sulphur and chlorine atomic centers in neutral molecules as well as anions H(-), OH(-) and F(-). The empty radial 2pr vacant orbital on the carbon center in CB11H11 , which corresponds to the LUMO, acts as a Lewis acid or electron attractor, as shown by the molecular electrostatic potential (MEP) and electron localization funcion (ELF). The thermochemistry and topological analysis of the complexes {CB11H11:LB} are comprehensively analyzed, and classified according to sharing or closed-shell interactions. ELF analysis shows that the tetrel C···X bond ranges from very polarised bonds, as in H11B11C:F() to very weak interactions as in H11B11C···FH and H11B11C···O=C=O.

scholarly journals Carboranes as Lewis Acids: Tetrel Bonding in CB11H11 Carbonium Ylide

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 391
Author(s):  
Maxime Ferrer ◽  
Ibon Alkorta ◽  
José Elguero ◽  
Josep M. Oliva-Enrich
Keyword(s):  
Lewis Acid ◽  
Lewis Acids ◽  
Molecular Electrostatic Potential ◽  
Weak Interactions ◽  
Topological Analysis ◽  
Closed Shell ◽  
Lewis Bases ◽  
High Level ◽  
Quantum Chemical Computations ◽  
Vacant Orbital

High-level quantum-chemical computations (G4MP2) are carried out in the study of complexes featuring tetrel bonding between the carbon atom in the carbenoid CB11H11—obtained by hydride removal in the C-H bond of the known closo-monocarbadodecaborate anion CB11H12(−) and acting as Lewis acid (LA)—and Lewis bases (LB) of different type; the electron donor groups in the tetrel bond feature carbon, nitrogen, oxygen, fluorine, silicon, phosphorus, sulfur, and chlorine atomic centres in neutral molecules as well as anions H(−), OH(−), and F(−). The empty radial 2pr vacant orbital on the carbon centre in CB11H11, which corresponds to the LUMO, acts as a Lewis acid or electron attractor, as shown by the molecular electrostatic potential (MEP) and electron localization function (ELF). The thermochemistry and topological analysis of the complexes {CB11H11:LB} are comprehensively analysed and classified according to shared or closed-shell interactions. ELF analysis shows that the tetrel C⋯X bond ranges from very polarised bonds, as in H11B11C:F(-) to very weak interactions as in H11B11C⋯FH and H11B11C⋯O=C=O.

Excitons in poly(para phenylene vinylene): a quantum-chemical perspective based on high-level ab initio calculations

2016 ◽  
Vol 18 (4) ◽  
pp. 2548-2563 ◽  
Author(s):  
Stefanie A. Mewes ◽  
Jan-Michael Mewes ◽  
Andreas Dreuw ◽  
Felix Plasser
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Quantum Chemical ◽  
Phenylene Vinylene ◽  
High Level ◽  
Quantum Chemical Computations

Exciton analyses of high-level quantum-chemical computations for poly(paraphenylene vinylene) reveal the nature of the excitonic bands in PPV oligomers.

scholarly journals Design of carborane molecular architectures with electronic structure computations: From endohedral and polyradical systems to multidimensional networks

2009 ◽  
Vol 81 (4) ◽  
pp. 719-729 ◽  
Author(s):  
Josep M. Oliva ◽  
Douglas J. Klein ◽  
Paul von Ragué Schleyer ◽  
Luis Serrano-Andrés
Keyword(s):  
Electronic Structure ◽  
Quantum Chemical ◽  
Triplet States ◽  
Triplet Energy ◽  
Self Assembling ◽  
Energy Gaps ◽  
Molecular Architectures ◽  
High Level ◽  
Quantum Chemical Computations ◽  
Structure Properties

The 12 cage-anchoring points of the very stable icosahedral ortho-, meta-, and para-carborane allow the design of multidimensional architectures provided new self-assembling routes are devised. We provide bases for constructing carborane molecular architectures through high-level quantum chemical computations. We consider ejection mechanisms for the inner atom/ion in endohedral carborane complexes, singlet-triplet energy gaps in carborane biradicals, as well as geometry reorganization in carborane neutral and dianionic triplet states. These features, explored in monomers, are starting points for the design of molecular architectures based on electronic structure properties of carborane assemblies.

The ortho-benzyne cation is not planar

2018 ◽  
Vol 20 (6) ◽  
pp. 3988-3996 ◽  
Author(s):  
D. Kaiser ◽  
E. Reusch ◽  
P. Hemberger ◽  
A. Bodi ◽  
E. Welz ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Ground State ◽  
Photoelectron Spectroscopy ◽  
Quantum Chemical ◽  
High Level ◽  
Quantum Chemical Computations

Mass-selected threshold photoelectron spectroscopy with synchrotron radiation and high-level quantum chemical computations revealed that the ground state of the ortho-benzyne cation exhibits a twisted geometry and that the ionisation energies have to be revised.

scholarly journals Standard Molar Enthalpies of Formation of Halomethanes Based on Quantum Chemical Computations

2020 ◽  
Author(s):  
Konstantinos Kalamatianos
Keyword(s):  
Gas Phase ◽  
Quantum Chemical ◽  
Halogen Bond ◽  
Chemical Processes ◽  
Enthalpies Of Formation ◽  
Isodesmic Reaction ◽  
Gold Standard Method ◽  
Ozone Destruction ◽  
Quantum Chemical Computations ◽  
Reaction Schemes

Accurate calculations of standard molar enthalpies of formation (ΔΗf°)m(g) and carbon-halogen bond dissociation enthalpies, BDE, of a variety of halomethanes with relevance on several atmospheric chemical processes and particularly to ozone destruction, were performed in the gas phase at 298.15 K. The (ΔΗf°)m(g) of the radicals formed through bond dissociations have also been computed. Ab initio computational methods and isodesmic reaction schemes were used. It is found that for the large majority of these species, the gold standard method of quantum chemistry (CCSD(T)) and even MP2 are capable to predict enthalpy values nearing chemical accuracy provided that isodesmic reaction schemes are used. New estimates for standard molar enthalpies of formation and BDE are suggested including for species that to our knowledge there are no experimental (ΔΗf°)m(g) (CHCl2Br, CHBr2Cl, CHBrCl, CHICl, CHIBr) or BDE values (CHCl2Br, CHBr2Cl, CHBrCl, CHICl, CHIBr) available in the literature. The method and calculational procedures presented may profitably be used to obtain accurate (ΔΗf°)m(g) and BDE values for these species.

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