Resonance interaction energy

The distribution parameter a reflects the root-mean square standard deviation of the non-resonance interaction energy D [cf. Eq. (13)] corresponding to the polarization energy of a charge carrier in a medium (cf. Sec. 2.3.1). The essential contribution to D is the difference of the van der Waals energies between an unexcited and excited molecule embedded in a medium of polarizability a. 

The optical absorption spectra of organic molecular solids are characterized by two kinds of intermolecular interaction energy, i.e., the Coulombic energy and the resonance interaction energy (Davydov, 1962, 1971). The former energy induces... 

The right-hand side of Eq. (3.9) is understood to be normally ordered. A is a constant energy term which may depend on the free exciton energy, on the static interaction energy, and on the deformation energy. J is the resonance interaction energy between neighboring monomers. The quasiparticle free equation (3.2) becomes in this case... 

Atomic and Molecular Energy Levels. Absorption and emission of electromagnetic radiation can occur by any of several mechanisms. Those important in spectroscopy are resonant interactions in which the photon energy matches the energy difference between discrete stationary energy states (eigenstates) of an atomic or molecular system = hv. This is known as the Bohr frequency condition. Transitions between... 

Total radical stabilization energy of 19.8 kcal/mol implies 10 kcal/mol of excess radical stabilization relative to the combined substituents. CH—N(CH3)2 rotational barrier is > 17 kcal/mol, implying strong resonance interaction. 

We assume that the double bonds in 1,3-butadiene would be the same as in ethylene if they did not interact with one another. Introduction of the known geometry of 1,3-butadiene in the s-trans conformation and the monopole charge of 0.49 e on each carbon yields an interaction energy <5 — 0.48 ev between the two double bonds. Simpson found the empirical value <5 = 1.91 ev from his assumption that only a London interaction was present. Hence it appears that only a small part of the interaction between double bonds in 1,3-butadiene is a London type of second-order electrical effect and the larger part is a conjugation or resonance associated with the structure with a double bond in the central position. 

IR VTMCD band in each of the [Fe3S4] spectra, therefore, corresponds to the uniaxial a- a transition of Fe-Fe interaction and the resonance delocalization energy, (3, is determined to be 4290 25 cm for Type 1 clusters and 4350 25 cm for Type 2 clusters. Hence, the Fe-Fe interactions within the valence-delocalized pair are very similar in both locations. 

Attempts were made at explaining the trends in reactivity through the use of both an electron-transfer model85 and a resonance interaction model,86,87 but without success. It seems that the trends in reactivity on a fine scale cannot be easily explained by such simple models, but instead depend on a multitude of factors, which may include the ionization potential of the metal, the electron affinity of the oxidant molecule, the energy gap between dns2 and dn+1s1 states, the M-O bond strength, and the thermodynamics of the reaction.57-81... 

When the gap is large, the sketch in Fig. 9 shows that a second channel will open when there is a vibrational resonance - that is, when eV = ho, with o one of the vibrational frequencies of the molecule. This is vibronic resonance, and energy will transfer from the momentum of the tunneling electrons into the vibrations of the molecule. The interaction is quite weak (because the tunneling time is so short) ... 

The recoilless nuclear resonance absorption of y-radiation (Mossbauer effect) has been verified for more than 40 elements, but only some 15 of them are suitable for practical applications [33, 34]. The limiting factors are the lifetime and the energy of the nuclear excited state involved in the Mossbauer transition. The lifetime determines the spectral line width, which should not exceed the hyperfine interaction energies to be observed. The transition energy of the y-quanta determines the recoil energy and thus the resonance effect [34]. 57Fe is by far the most suited and thus the most widely studied Mossbauer-active nuclide, and 57Fe Mossbauer spectroscopy has become a standard technique for the characterisation of SCO compounds of iron. 

Because of the opposite nature of the n interactions between the ring and either the nitro or the amino substituent, let us assess the stabilization energies of nitrobenzene and aniline. In equation 13, the resonance stabilizing energy of aniline was defined as the exothermicity of a reaction involving arbitrary reference states. By analogy to equation 13, we may write equation 57 for nitrobenzene and the same arbitrary reference states, R = /-Pr or t-Bu. 

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