Chemical Behavior of Charge-transfer Complexes, VI. Catalysis of Acetolysis of 2,4,7-Trinitro-9-fluorenyl p-Toluenesulfonate by Aromatic Hydrocarbon Donors

1974 ◽  
Vol 52 (22) ◽  
pp. 3748-3757 ◽  
Author(s):  
Allan K. Colter ◽  
Arthur L. McKenna ◽  
M. A. Kasem
Keyword(s):  
Charge Transfer ◽  
Aromatic Hydrocarbon ◽  
Transition State ◽  
Molecular Orbital ◽  
Orbital Energy ◽  
Charge Transfer Complexes ◽  
Substrate Complex ◽  
Donor Substrate ◽  
Highest Occupied Molecular Orbital ◽  
Π Complex

The catalytic effectiveness of eleven aromatic hydrocarbon donors in the acetolysis of 2,4,7-trinitro-9-fluorenyl p-toluenesulfonate (TNF-OTs) has been examined. For nine of these donors, the kinetic data were analyzed to obtain the rate constant, kc, for acetolysis of the 1:1 donor–substrate complex, and the 1:1 donor–substrate association constant, K. Two measures of catalytic effectiveness, log kc and log kcK correlate well with the highest occupied molecular orbital energy of the donor, E(HOMO), calculated by the Hückel molecular orbital (HMO) method. The success of these correlations is considered to mean that the transition state for acetolysis resembles a π-complex. A model based on Mulliken's charge-transfer theory in its simplest form leads to an estimate of 0.11 of an electron transferred from the donor to the acceptor substrate in the complexed transition state.

On the Nature of Halide-Water Interactions: Insights from Many-Body Representations and Density Functional Theory

2019 ◽  
Author(s):  
Brandon B. Bizzarro ◽  
Colin K. Egan ◽  
Francesco Paesani
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Molecular Orbital ◽  
Density Functional ◽  
Decomposition Analysis ◽  
Orbital Energy ◽  
Energy Decomposition Analysis ◽  
Interaction Energies ◽  
Many Body ◽  
Functional Theory

<div> <div> <div> <p>Interaction energies of halide-water dimers, X<sup>-</sup>(H<sub>2</sub>O), and trimers, X<sup>-</sup>(H<sub>2</sub>O)<sub>2</sub>, with X = F, Cl, Br, and I, are investigated using various many-body models and exchange-correlation functionals selected across the hierarchy of density functional theory (DFT) approximations. Analysis of the results obtained with the many-body models demonstrates the need to capture important short-range interactions in the regime of large inter-molecular orbital overlap, such as charge transfer and charge penetration. Failure to reproduce these effects can lead to large deviations relative to reference data calculated at the coupled cluster level of theory. Decompositions of interaction energies carried out with the absolutely localized molecular orbital energy decomposition analysis (ALMO-EDA) method demonstrate that permanent and inductive electrostatic energies are accurately reproduced by all classes of XC functionals (from generalized gradient corrected (GGA) to hybrid and range-separated functionals), while significant variance is found for charge transfer energies predicted by different XC functionals. Since GGA and hybrid XC functionals predict the most and least attractive charge transfer energies, respectively, the large variance is likely due to the delocalization error. In this scenario, the hybrid XC functionals are then expected to provide the most accurate charge transfer energies. The sum of Pauli repulsion and dispersion energies are the most varied among the XC functionals, but it is found that a correspondence between the interaction energy and the ALMO EDA total frozen energy may be used to determine accurate estimates for these contributions. </p> </div> </div> </div>

scholarly journals QTAIM investigation of bis(pyrazol-1-yl)methane derivative and its Zn(II) complexes (ZnLX2, X=Cl, Br or I)

2015 ◽  
Vol 80 (8) ◽  
pp. 997-1008 ◽  
Author(s):  
Maryam Dehestani ◽  
Leila Zeidabadinejad
Keyword(s):  
Molecular Orbital ◽  
Critical Points ◽  
Structural Parameters ◽  
Frontier Molecular Orbital ◽  
Orbital Energy ◽  
Theory Approach ◽  
Topological Parameters ◽  
Molecular Orbital Energy ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

Topological analyses of the electron density using the quantum theory of atoms in molecules (QTAIM) have been carried out at the B3PW91/6-31g (d) theoretical level, on bis(pyrazol-1-yl)methanes derivatives 9-(4-(di (1H-pyrazol-1-yl)-methyl)phenyl)-9H-carbazole (L) and its zinc(II) complexes: ZnLCl2 (1), ZnLBr2 (2) and ZnLI2 (3). The topological parameters derived from Bader theory were also analyzed; these are characteristics of Zn-bond critical points and also of ring critical points. The calculated structural parameters are the frontier molecular orbital energies highest occupied molecular orbital energy (EHOMO), lowest unoccupied molecular orbital energy (ELUMO), hardness (?), softness (S), the absolute electronegativity (?), the electrophilicity index (?) and the fractions of electrons transferred (?N) from ZnLX2 complexes to L. The numerous correlations and dependencies between energy terms of the Symmetry Adapted Perturbation Theory approach (SAPT), geometrical, topological and energetic parameters were detected and described.

Introduction

2003 ◽  
Author(s):  
Toshiaki Enoki ◽  
Morinobu Endo ◽  
Masatsugu Suzuki
Keyword(s):  
Electronic Structure ◽  
Charge Transfer ◽  
Ionization Potential ◽  
Molecular Orbital ◽  
Electron Affinity ◽  
Basic Unit ◽  
Charge Transfer Complexes ◽  
Vacuum Level ◽  
2D System ◽  
Lowest Unoccupied Molecular Orbital

There are two important features in the structure and electronic properties of graphite: a two-dimensional (2D) layered structure and an amphoteric feature (Kelly, 1981). The basic unit of graphite, called graphene is an extreme state of condensed aromatic hydrocarbons with an infinite in-plane dimension, in which an infinite number of benzene hexagon rings are condensed to form a rigid planar sheet, as shown in Figure 1.1. In a graphene sheet, π-electrons form a 2D extended electronic structure. The top of the HOMO (highest occupied molecular orbital) level featured by the bonding π-band touches the bottom of the LUMO (lowest unoccupied molecular orbital) level featured by the π*-antibonding band at the Fermi energy EF, the zero-gap semiconductor state being stabilized as shown in Figure 1.2a. The AB stacking of graphene sheets gives graphite, as shown in Figure 1.3, in which the weak inter-sheet interaction modifies the electronic structure into a semimetallic one having a quasi-2D nature, as shown in Figure 1.2b. Graphite thus features a 2D system from both structural and electronic aspects. The amphoteric feature is characterized by the fact that graphite works not only as an oxidizer but also as a reducer in chemical reactions. This characteristic stems from the zero-gap-semiconductor-type or semimetallic electronic structure, in which the ionization potential and the electron affinity have the same value of 4.6 eV (Kelly, 1981). Here, the ionization potential is defined as the energy required when we take one electron from the top of the bonding π-band to the vacuum level, while the electron affinity is defined as the energy produced by taking an electron from the vacuum level to the bottom of the anti-bonding π*-band. The amphoteric character gives graphite (or graphene) a unique property in the charge transfer reaction with a variety of materials: namely, not only an electron donor but also an electron acceptor gives charge transfer complexes with graphite, as shown in the following reactions: . . .xC + D → D+ C+x. . . . . .(1.1). . . . . .xC + A → C+x A−. . . . . .(1.2). . . where C, D, and A are graphite, donor, and acceptor, respectively.

Charge-transfer complexes of purines and pyrimidines

1968 ◽  
Vol 21 (2) ◽  
pp. 419 ◽  
Author(s):  
A Fulton ◽  
LE Lyons
Keyword(s):  
Charge Transfer ◽  
Field Method ◽  
Charge Transfer Complexes ◽  
Absorption Bands ◽  
Consistent Field ◽  
Highest Occupied Molecular Orbital ◽  
Self Consistent Field ◽  
Semi Empirical ◽  
Purines And Pyrimidines ◽  
Good Agreement

The spectra of 20 purines and pyrimidines with chloranil, bromanil, and p-benzoquinone in dimethyl sulphoxide were studied. Most of the systems exhibited absorption bands which were concluded to be charge transfer in nature. The ionization energies of the molecules, derived from the positions of the bands, correlated well with the highest occupied molecular orbital energies calculated using the simple H�ckel method and were also in good agreement with ionization energy values calculated by a semi-empirical self-consistent field method.

Electrical conductivity of aromatic hydrocarbon-iodine charge transfer complexes

1992 ◽  
Vol 27 (1) ◽  
pp. 98-100 ◽  
Author(s):  
N. Gogulamurali ◽  
S. A. Suthanthiraraj ◽  
P. Maruthamuthu
Keyword(s):  
Electrical Conductivity ◽  
Charge Transfer ◽  
Aromatic Hydrocarbon ◽  
Charge Transfer Complexes

Discriminative modulation of the highest occupied molecular orbital energies of graphene and carbon nanotubes induced by charging

2015 ◽  
Vol 17 (11) ◽  
pp. 7248-7254 ◽  
Author(s):  
Hongping Yang ◽  
Chi-yung Yam ◽  
Aihua Zhang ◽  
Zhiping Xu ◽  
Jun Luo ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Molecular Orbital ◽  
First Principles ◽  
Orbital Energy ◽  
First Principles Calculations ◽  
Orbital Energies ◽  
Molecular Orbital Energy ◽  
Highest Occupied Molecular Orbital

First-principles calculations show that the increase in the highest occupied molecular orbital energy of a charged carbon nanotube is different from graphene.

Sign in / Sign up

Export Citation Format

Share Document