Energetic interaction energetically favorable

In the lowest optieally excited state of the molecule, we have one eleetron (ti ) and one hole (/i ), each with spin 1/2 which couple through the Coulomb interaetion and can either form a singlet 5 state (5 = 0), or a triplet T state (S = 1). Since the electric dipole matrix element for optical transitions — ep A)/(me) does not depend on spin, there is a strong spin seleetion rule (AS = 0) for optical electric dipole transitions. This strong spin seleetion rule arises from the very weak spin-orbit interaction for carbon. Thus, to turn on electric dipole transitions, appropriate odd-parity vibrational modes must be admixed with the initial and (or) final electronic states, so that the w eak absorption below 2.5 eV involves optical transitions between appropriate vibronic levels. These vibronic levels are energetically favored by virtue... 

Hydrophilic hydration signifies that a strong energetically favored direct interaction exists between dissolved polar or ionic particle and the surrounding water molecules by ion-dipole-, dipole-dipole-interactions and/or hydrogen bonds. 

In the linear konjac mannan, the degree of acetylation profoundly affects the solubility and flow properties of this hydrocolloid. The acetyl substitution prevents self-association of the mannan chains, but following deacetylation chain interactions become more energetically favorable [230]. 

The interaction of drug molecules with biological membranes is a three-dimensional (3D) recognition that is mediated by surface properties such as shape, Van der Waals forces, electrostatics, hydrogen bonding, and hydrophobicity. Therefore, the GRID force field [5-7], which is able to calculate energetically favorable interaction sites around a molecule, was selected to produce 3D molecular interaction fields. 

This, however, is not the only way multilayers of polymers can be formed. If the macromolecule is a compactly folded copolymer, such as a protein, its collapsed state will be determined by internal compensation of energetically favorable interactions. 

FIGURE 3.6 Some types of orbital overlap that lead to energetically favorable interactions. 

The energetically favorable conformations of model alkyl nitronate (88) and related compounds (89 to 91) (283) were determined by the B3LYP/6-31G(d) method (see Chart 3.9). It appeared that the marked conformations with the minimized dipole moments are energetically most favorable for compounds (88-91) (the use of the dipole-dipole interaction model in conformational analysis was also described in the publication (284)). Calculations including n-n interactions (see Fig. 3.1) did not change this situation because the contribution of this effect is equal in magnitude for both limiting conformations shown in Chart 3.9. 

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