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Excitation energy

This relationship, though approximate, justifies in part the use of orbital energy changes alone in discussing molecular structure and reactivity problems. [Pg.157]

Electron configuration 8.2 is atypical closed shell in which all the occupied MOs are doubly filled. Let us examine the stability of such a state with respect to those states in which some of the high lying occupied MOs are singly filled. To simplify our discussion, consider the various electronic configurations shown in 8.3, which result [Pg.157]

Application of the variation principle to equation 8.35 leads to the Fock equation [Pg.157]

Note that the MOs i/f, ( = 1,2) are determined if F is known, but F is defined in terms of the occupied MO i/r, (via j, and K ) that is yet to be determined. This problem is solved by the method of self-consistent field (SCF) iteration in the first cycle of [Pg.157]

6 is the effective potential exerted on an electron in the MO of g- If extra electron is placed in the MO xj/2 of 5 g, that electron would feel the effective potential given by 62. In all the electronic states of 8.3, the molecular geometry is assumed to be the same so that the relative stability of those states can be examined by simply comparing their electronic energies. [Pg.158]


Chemical properties of deposited monolayers have been studied in various ways. The degree of ionization of a substituted coumarin film deposited on quartz was determined as a function of the pH of a solution in contact with the film, from which comparison with Gouy-Chapman theory (see Section V-2) could be made [151]. Several studies have been made of the UV-induced polymerization of monolayers (as well as of multilayers) of diacetylene amphiphiles (see Refs. 168, 169). Excitation energy transfer has been observed in a mixed monolayer of donor and acceptor molecules in stearic acid [170]. Electrical properties have been of interest, particularly the possibility that a suitably asymmetric film might be a unidirectional conductor, that is, a rectifier (see Refs. 171, 172). Optical properties of interest include the ability to make planar optical waveguides of thick LB films [173, 174]. [Pg.560]

These results do not agree with experimental results. At room temperature, while the translational motion of diatomic molecules may be treated classically, the rotation and vibration have quantum attributes. In addition, quantum mechanically one should also consider the electronic degrees of freedom. However, typical electronic excitation energies are very large compared to k T (they are of the order of a few electronvolts, and 1 eV corresponds to 10 000 K). Such internal degrees of freedom are considered frozen, and an electronic cloud in a diatomic molecule is assumed to be in its ground state f with degeneracy g. The two nuclei A and... [Pg.405]

If the excitation energy required to fomi activated species A is much larger than k T its concentration will remain small. This is fulfilled if k Following Bodenstein, [A ] is then assumed to be quasi-stationary,... [Pg.787]

An interferometric method was first used by Porter and Topp [1, 92] to perfonn a time-resolved absorption experiment with a -switched ruby laser in the 1960s. The nonlinear crystal in the autocorrelation apparatus shown in figure B2.T2 is replaced by an absorbing sample, and then tlie transmission of the variably delayed pulse of light is measured as a fiinction of the delay This approach is known today as a pump-probe experiment the first pulse to arrive at the sample transfers (pumps) molecules to an excited energy level and the delayed pulse probes the population (and, possibly, the coherence) so prepared as a fiinction of time. [Pg.1979]

E is the excitation energy relative to the lowest dissociation limit (I). Adapted from Rosker et a [74],... [Pg.2128]

Flowers M C and Rabinovitch B S 1985 Localization of excitation energy in chemically activated systems. 3-ethyl-2-methyl-2-pentyl radicals J. Rhys. Chem. 89 563-5... [Pg.2150]

As a scientific tool, ab initio quantum chemistry is not yet as accurate as modem laser spectroscopic measurements, for example. Moreover, it is difficult to estimate the accuracies with which various methods predict bond energies and lengths, excitation energies and the like. In the opinion of tlie author, chemists who... [Pg.2158]

Rowe D J 1968 Equation-of-motion method and the extended shell model Rev. Mod. Phys. 40 153-66 I applied these ideas to excitation energies in atoms and molecules in 1971 see equation (2.1)-(2.6) in ... [Pg.2200]

Towler M D, Flood R Q and Needs R J 2000 Minimum principles and level splitting in quantum Monte Carlo excitation energies application to diamond Phys. Rev. B 62 2330-7... [Pg.2233]

Nitrogen molecules, a major constituent of air, are excited by electron collisions and the excitation energy is transferred to the O 2 molecules, or the N2 molecules may be dissociated and O atoms fonned via the reactions... [Pg.2809]

Agranovioh V M and Galanin M D 1982 Electronic Excitation Energy Transfer in Condensed Maffer (Amsterdam Elsevier/North-Flolland)... [Pg.3030]

The first study was made on the benzene molecule [79], The S ISi photochemistry of benzene involves a conical intersection, as the fluorescence vanishes if the molecule is excited with an excess of 3000 crn of energy over the excitation energy, indicating that a pathway is opened with efficient nonradiative decay to the ground state. After irradiation, most of the molecules return to benzene. A low yield of benzvalene, which can lead further to fulvene, is, however, also obtained. [Pg.302]

Pariser and Pair adjusted the necessary parameters to the empirical singlet and tr iplet excitation energies in benzene to obtain... [Pg.251]

Practically all CNDO calculations are actually performed using the CNDO/ 2 method, which is an improved parameterization over the original CNDO/1 method. There is a CNDO/S method that is parameterized to reproduce electronic spectra. The CNDO/S method does yield improved prediction of excitation energies, but at the expense of the poorer prediction of molecular geometry. There have also been extensions of the CNDO/2 method to include elements with occupied d orbitals. These techniques have not seen widespread use due to the limited accuracy of results. [Pg.34]

There are a some known cases where MNDO gives qualitatively or quantitatively incorrect results. Computed electronic excitation energies are underestimated. Activation barriers tend to be too high. The correct conformer is not... [Pg.34]

The CIS(D) method is designed to include some correlation in excited states. Initial results with this method show that it is stable and reliable and gives excitation energies significantly more accurate than those of CIS. [Pg.217]

The excitation energy AE measures the spacing between the final (subscript f) and initial (subscript i) quantum states of the electron ... [Pg.461]

In principle, the excitation energy would be expected to be distributed between ketones (5)and (6) in a ratio dependent on the substituent R, and the distribution would be expected to favor the ketone having the lowest triplet excitation energy. [Pg.263]

Subsequent studies (63,64) suggested that the nature of the chemical activation process was a one-electron oxidation of the fluorescer by (27) followed by decomposition of the dioxetanedione radical anion to a carbon dioxide radical anion. Back electron transfer to the radical cation of the fluorescer produced the excited state which emitted the luminescence characteristic of the fluorescent state of the emitter. The chemical activation mechanism was patterned after the CIEEL mechanism proposed for dioxetanones and dioxetanes discussed earher (65). Additional support for the CIEEL mechanism, was furnished by demonstration (66) that a linear correlation existed between the singlet excitation energy of the fluorescer and the chemiluminescence intensity which had been shown earher with dimethyl dioxetanone (67). [Pg.266]

Addition of fluorescent energy acceptors such as 9,10-dibromoanthracene substantially increases chemiluminescence intensity by transferring excitation energy (132,133), as is the case with dioxetanes. [Pg.269]


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1.2- Dioxetanes excited state energy

4f excitation energies, calculations

Absorption of the Excitation Energy

Acetone, addition reactions excited state energies

Activation energy with excited species

Activation free energy excited state

Alcohols, acidity excitation energy

Amino acids, mean excitation energy

Anderson Hamiltonian excitation energies

Anthracene cation, excitation energies

Atom energy state, excited

Average excitation energy approximation

Avogadro’s number Forster electronic excitation energy transfer

Azines excitation energies

Azulene excitation energy

Benzene Excitation Energies

Benzene, additional reactions excited state energies

Calculated first singlet excitation energy

Carbon electronic excitation energy

Cascade, directed excited-state energy

Cascade, directed excited-state energy transfer

Charge distribution excitation energies

Clusters vibrational energy excitation

Collision-induced excitation energy

Completeness excitation energies

Core electron excitation binding energies

Core electron excitation energy level diagram

Core electrons excitation energy

Core excitation energies

Core excitation energies calculations

Core excitation energies characterization

Core excitation energies combined treatment

Core excitation energies conclusions

Core excitation energies discussions

Correlation energy doubly excited configurations

Correlation energy quadruple excitations

Correlation energy triply excited configurations

Correlation potentials, ground-state exchange first excitation energies

Critical excitation energy

Cylinder morphology, molecular dyes in zeolite Forster electronic excitation energy transfer

Density functionals electronic excitation energy

Dye molecules, zeolite L channels electronic excitation energy transfer

EOMCC method vertical excitation energy

Electrical excitation Forster energy transfer

Electrical excitation energy transfer, dye molecules in zeolite

Electronic Excitation Energies and Transition Moments

Electronic Excitation and Ionization Energies

Electronic Excitations and Energy Transfer in PCSs

Electronic excitation energy

Electronic excitation energy 588 INDEX

Electronic excitation energy Stokes shift

Electronic excitation energy differences

Electronic excitation energy excited triplet state

Electronic excitation energy fluorescence

Electronic excitation energy phosphorescence

Electronic excitation energy relaxation

Electronic excitation energy selection rules

Electronic excitation energy transfer

Electronically excited molecule energy level diagrams

Electronically excited molecules potential energy diagram

Electrons excitation energy

Energies for excitations

Energy (continued excitation

Energy Balance of Plasma-Chemical NO Synthesis Zeldovich Mechanism Stimulated by Vibrational Excitation

Energy Efficiency of Plasma-Chemical NO Synthesis Excitation and Relaxation Factors

Energy Efficiency of Plasma-Chemical Processes Stimulated by Electronic Excitation and Dissociative Attachment

Energy Exchange with Electronically Excited Molecules

Energy Levels of Excited Molecules

Energy Pooling in Collisions Between Excited Atoms

Energy Transfer By Excited States

Energy Transfer in the Excited Triplet State

Energy collisional, from excited

Energy dependence vibrational excitation intensity

Energy deposition process electronic excitation

Energy efficiency excitation factor

Energy excited electronic

Energy excited states and

Energy excited transition

Energy level diagram first excited singlet state

Energy level diagram second singlet excited state

Energy level excitation, nonadiabatic

Energy levels metastable excited

Energy of excited

Energy rotational excitation

Energy selectivity electronic excitation

Energy transfer MLCT excited state

Energy transfer excitation transport

Energy transfer excited state

Energy transfer in electronically excited

Energy with excited reagents

Ethylenes excitation energy

Excess excitation energy

Exchange-correlation potential excitation energy

Excitation Energy (Quantum Theory and Atomic Spectra)

Excitation Energy Hopping in Multichromophoric Cyclodextrins

Excitation Energy of the Fission Fragments

Excitation and Ionization Energies

Excitation discharge, vacuum energy

Excitation energies adiabatic

Excitation energies and energy gaps

Excitation energies and oscillator

Excitation energies biphenyl

Excitation energies extended systems

Excitation energies five states, derivation

Excitation energies four states derivation

Excitation energies imidazole molecule

Excitation energies indole molecule

Excitation energies linear conjugated polyenes

Excitation energies metal shielding

Excitation energies of Ba

Excitation energies properties

Excitation energies study

Excitation energies transition metals

Excitation energies vertical

Excitation energies wave function)

Excitation energy HMO model

Excitation energy Hartree-Fock theory

Excitation energy calculations

Excitation energy distribution

Excitation energy distribution between the photosystems

Excitation energy electrochemiluminescence

Excitation energy electronic partition

Excitation energy exchange-correlation functional

Excitation energy migration

Excitation energy moderate pumping

Excitation energy of singlet

Excitation energy quantum chemical calculation

Excitation energy semiempirical calculations

Excitation energy spectroscopic constants

Excitation energy transfer

Excitation energy transfer between isotopes

Excitation energy transfer donor-bridge-acceptor system

Excitation energy transfer from fucoxanthin

Excitation energy transfer quenching method

Excitation energy transport

Excitation energy, average

Excitation energy, average dependence

Excitation energy, charge-transfer

Excitation energy, charge-transfer transitions

Excitation energy, fate

Excitation energy, first

Excitation energy, first from correlation potentials

Excitation energy, ionization potential, and electron affinity (RHF approach)

Excitation photon energy

Excitation probability, molecular dyes in zeolite energy transfer

Excitation with High Energy Particles

Excitation-energy requirements

Excited Energy Transfer

Excited Singlet Energy Transfer and Migration

Excited State Electron and Energy Transfer Reactions

Excited molecule intramolecular energy transfer

Excited singlet energy transfer event

Excited singlet state energy

Excited state energy

Excited state energy and redox potentials

Excited state energy barriers

Excited state, formation potential energy

Excited states energy surfaces

Excited states, energy dissipation from

Excited transition, energy density required

Excited triplet state energy

Excited-state energy, with hydrogenated

Factors Associated with Excitation Energy Conversion

Formaldehyde valence excitation energies

Frozen-orbital approximation excitation energies

Fucoxanthin excitation energy transfer

High-energy excited state emission

Higher excited states, energy dependent relaxation

Higher triplet excited states, energy transfer

Initial excitation energy

Interconfigurational excitation energy

Internal excitation energy

Intramolecular excitation energy

Intramolecular excitation energy migration

Intramolecular vibrational energy overtone excitation

Iodine excited, energy transfer from

Ionisation Energy and Number of Excited Atoms

Laser excitation energy

Lead isotopes excitation energies

Low energy excitations

Low lying excitation energies

Low-energy excitation mode

Lowest energy excitation

Lowest energy excited state

Lowest energy excited state substitutions

Maximum Efficiency for High Energy Excitation

Mean excitation energy

Mean excitation energy hydrogen bond

Mean excitation energy nucleobases

Mean excitation energy nucleosides

Mixed-valence compounds localization, excitation energy

Molecular vibrations excitation energy

Morphology Dependence of Excited Singlet Energy Transfer Events

Naphthalene decay rate, excitation energy dependence

Naphthalene excitation energy

Naphthalene fluorescence, excitation energy

Naphthalene spectroscopy excitation energies

Nonradiative excitation energy transfer

Nonradiative excitation energy transfer NRET)

Operators excitation energy

Optical Excitation of Luminescence and Energy Transfer

Photo-excitation photon energy

Photoluminescence electronic excitation energy

Photophysics vertical excitation energies

Photosynthesis excitation energy transfer

Polyoxometalates excited state energies

Polypeptides, mean excitation energy

Porphyrinic chromophore, energy transfers excited states

Potential Energy Surfaces for Ground and Excited States

Potential energy curves electronic excitation

Potential energy curves in excited electronic states

Potential energy functions first excited singlet state

Potential energy surface excited isomers

Potential energy surface excited-state

Potential energy surfaces infrared laser excitation

Quenching energy loss from excited species

Quenching of excitation energy

RET between like molecules. Excitation energy migration in assemblies of chromophores

Radiation, basic concepts excitation energy

Related Excited-State Energy-Transfer Processes

Relativistic excitation energies

Resonance-excitation energy transfer

S2 Excitation Energies

Selective Excitation and Energy Transfer

Semiconductor excitation energies

Semiempirical Calculations of Excitation Energies

Sensitization energy level, triplet excited

Silicon excitation energy

Single-Particle Eigenvalues and Excited-State Energies

Singlet and triplet excitation energies

Singlet excitation energy

Singlet excitation energy transfer

Spectroscopic excited state energy from redox

Spectroscopic excited state energy from redox potentials

Spin excitation energy

Stilbene, absorption spectrum excited state energies

Supramolecularly organized luminescent dye electronic excitation energy transfer

Thallation charge transfer excitation energies

The Lowest Energy Excited Singlet State

Theory and Experiment of Singlet Excitation Energy Transfer in Mixed Molecular Crystals

Thermochemical excitation energy

Thermochemical excitation energy distribution

Thiophenes excitation energies

Time-independent theories, single excited state excitation energies

Total Energy Efficiency Excitation, Relaxation, and Chemical Factors

Transfer of Excitation Energy Sensitisation and Quenching

Transition excitation energies

Triple-excitation energy

Triple-excitation energy component

Triplet excitation energies

Triplet excited states energy transfer from

Triplet, energy levels, determination excitation

Ultrafast electronic-excitation energy

Ultrafast electronic-excitation energy transfer

Unimolecular Reactions and Energy Transfer of Highly Excited Molecules

Uracil vertical excitation energies

Valence excitation energies

Valence excited state energy

Variation method excited state energies

Vertical and Adiabatic Excitation Energies

Vibrational excitation energy loss rate

Vibrational excitation energy, molecular

Wavepacket excited-state potential-energy surface

Zeolite L channels, supramolecularly organized electronic excitation energy transfer

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