Dipole moments, charge-transfer parameters, and ionization potentials of the methyl-substituted benzene–tetracyanoethylene complexes

1970 ◽  
Vol 48 (2) ◽  
pp. 299-305 ◽  
Author(s):  
R. K. Chan ◽  
S. C. Liao
Keyword(s):  
Charge Transfer ◽  
Carbon Tetrachloride ◽  
Dipole Moments ◽  
Ionization Potentials ◽  
Charge Transfer Complexes ◽  
Variation Principle ◽  
Charge Transfer Transition ◽  
Transition Energies ◽  
Vertical Ionization Potentials ◽  
Transfer Parameters

The dipole moments of a series of charge-transfer complexes of methylbenzenes with tetracyano-ethylene in carbon tetrachloride solutions at 25 °C and the various parameters derived from Mulliken's theory have been evaluated. The energies of various states of the complexes were calculated via their relationships with the parameters, charge-transfer transition energies, and heats of formation of the complexes by means of the variation principle. Vertical ionization potentials of the donors were obtained from the calculated energies of the dative structures of the complexes. The dipole moments contributed from the charge-transfer interaction can also be reasonably interpreted as charge-transfer energies in terms of vertical ionization potentials of the donors.

scholarly journals Optical anisotropy and charge-transfer transition energies in BiFeO3from 1.0 to 5.5 eV

2011 ◽  
Vol 83 (10) ◽  
Author(s):  
S. G. Choi ◽  
H. T. Yi ◽  
S.-W. Cheong ◽  
J. N. Hilfiker ◽  
R. France ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Optical Anisotropy ◽  
Charge Transfer Transition ◽  
Transition Energies

Application of time-resolved linear dichroism spectroscopy: Intensity borrowing in charge transfer complex absorption spectra

2003 ◽  
Vol 81 (6) ◽  
pp. 567-574
Author(s):  
Dustin Levy ◽  
Bradley R Arnold
Keyword(s):  
Charge Transfer ◽  
Charge Transfer Complex ◽  
Chlorinated Solvents ◽  
Linear Dichroism ◽  
Charge Transfer Transition ◽  
Time Resolved ◽  
Transition Energies ◽  
Charge Transfer Transitions ◽  
Donor Acceptor ◽  
Influence Of Solvent

Time-resolved linear dichroism spectroscopy has been used to study the influence of solvent on the charge transfer complex formed between hexamethylbenzene and 1,2,4,5-tetracyanobenzene. It was shown that cyano-substituted solvents induce a 1500 cm–1 increase in the charge transfer transition energies relative to those observed in chlorinated solvents. Furthermore, the angle between the charge transfer absorption transition moments and the photochemically produced radical anion absorption transition moment, after relaxation, has been measured for this complex in several solvents. A simple model was used to correlate the angles measured using time-resolved linear dichroism spectroscopy with the extent of localized excitation mixed into the charge transfer transitions. These measurements reveal that different charge transfer transitions borrow intensity from the localized excitation to different extents. By using different excitation wavelengths, the partitioning of the borrowed intensity among the charge transfer transitions of this complex could be evaluated for the first time.Key words: 1,2,4,5-tetracyanobenzene, hexamethylbenzene, donor–acceptor complex, photoinduced electron transfer, photoselection.

Effects of Solvent-Salt Charge-Transfer Complexes on Oxidative Stability of Li-Ion Battery Electrolytes

2018 ◽  
Author(s):  
Eric Fadel ◽  
Francesco Faglioni ◽  
Georgy Samsonidze ◽  
Nicola Molinari ◽  
Boris V. Merinov ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Individual Component ◽  
Oxidation Potential ◽  
Computational Techniques ◽  
Charge Transfer Complexes ◽  
Anion Complex ◽  
Vertical Ionization Potentials ◽  
Li Ion ◽  
Solvent Clusters ◽  
Operating Regimes

Electrochemical stability windows of electrolytes largely determine the limitations of operating regimes and energy density of Li-ion batteries but the controlling degradation mechanisms are difficult to characterize and remain poorly understood. We investigate the oxidative decomposition mechanisms governing high voltage stability of multi-component organic electrolytes using computational techniques of quantum chemistry. The intrinsic oxidation potential is modeled using vertical ionization potentials (IP) of ensembles of anion-solvent clusters generated using molecular dynamics. In some cases, the IP of the solvent-anion complex is significantly lower than that of each individual component. This effect is found to originate from the oxidation-driven charge transfer complex formation between the anion and the solvent. We propose a simple model to quantitatively understand this phenomenon and validate it for 16 combinations of common anions (4,5-dicyano-2-(trifluoromethyl)imidazolium, bis-(trifluoromethane solfonimmide), tetrafluroborate, hexafluorophosphate) and solvents (dimethyl sulfoxide, dimethoxyethane, propylene carbonate, acetonitrile). This new understanding of the microscopic details of oxidation allows us to interpret trends in published experimental and computational results and to formulate design rules for rapidly assessing stability of electrolyte compositions.

Stark spectroscopy of mixed-valence systems

2007 ◽  
Vol 366 (1862) ◽  
pp. 33-45 ◽  
Author(s):  
Lisa N Silverman ◽  
Pakorn Kanchanawong ◽  
Thomas P Treynor ◽  
Steven G Boxer
Keyword(s):  
Charge Transfer ◽  
Electric Fields ◽  
Dipole Moments ◽  
Mixed Valence ◽  
Quantitative Information ◽  
Stark Spectroscopy ◽  
Charge Transfer Transition ◽  
Band Position ◽  
Stark Effects ◽  
Intervalence Charge Transfer

Many mixed-valence systems involve two or more states with different electric dipole moments whose magnitudes depend upon the charge transfer distance and the degree of delocalization; these systems can be interconverted by excitation of an intervalence charge transfer transition. Stark spectroscopy involves the interaction between the change in dipole moment of a transition and an electric field, so the Stark spectra of mixed-valence systems are expected to provide quantitative information on the degree of delocalization. In limiting cases, a classical Stark analysis can be used, but in intermediate cases the analysis is much more complex because the field affects not only the band position but also the intrinsic bandshape. Such non-classical Stark effects lead to widely different bandshapes. Several examples of both classes are discussed. Because electric fields are applied to immobilized samples, complications arise from inhomogeneous broadening, along with other effects that limit our ability to extract unique parameters in some cases. In the case of the radical cation of the special pair in photosynthetic reaction centres, where the mixed-valence system is in a very complex but structurally well-defined environment, a detailed analysis can be performed.

Molecular Complexes of p-Chloranil with Aniline, Phenol and their Derivatives

2015 ◽  
Vol 670 ◽  
pp. 89-94
Author(s):  
Boris S. Pryalkin ◽  
Yulia S. Bodagova
Keyword(s):  
Charge Transfer ◽  
Electron Acceptor ◽  
Photoelectron Spectroscopy ◽  
Spectral Properties ◽  
Molecular Complexes ◽  
Ionization Potentials ◽  
Wide Range ◽  
Vertical Ionization Potentials ◽  
Vertical Ionization Energies

Classification of simple supramolecular structures (for example molecular complexes), which has been introduced and described by Mulliken [1], is based on types of molecular orbitals of the components. In the paper [2], disadvantages of such classification are shown, which motivate us to return to the re-examination properties of molecular complexes. By this reason, there is a need to research the molecular complexes of one electron acceptor with a wide range of electron donor molecules. This paper have continued work (Part I [3]) on the chloranil complexes by studying the spectral properties complexes of N- and O-unsubstituting anilines and phenols. The present work aimed at analyzing linear relation the energies of charge-transfer bands of molecular complexes are related to ionization potentials of the donor components. All complexes conform to linear relations like involving both adiabatic and vertical ionization potentials of donor components. Mulliken [1] has been proposed to apply the vertical ionization potentials of donor components only. The development of photoelectron spectroscopy has led to the measurement of adiabatic and vertical ionization energies for thousands of molecules, which allow theirs to the present analysis of spectral properties molecular complexes.

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