Intramolecular interaction contribution

To summarize, the insertion of EDOT in precursors of polymer leads to a decrease of the polymerization potential and improves the efficiency of electropolymerization process due to the high reactivity of terminal EDOT radical cation. In addition to these electronic effects, the spontaneous planarization of some EDOT-based precursors by S-O or S-N intramolecular interactions contributes to reduce the bandgap of the polymers. 

Page, M. L., Jencks, W. P. Entropic contributions to rate accelerations in enzymic and intramolecular interactions and the chelate effect. Proc. Natl. Acad. Sci. USA 68 (1971) 1678-1683... 

Table 6. Total Lattice Sums for Trans and Gauche Conformations in PET and Contributions from Intramolecular Interactions...

It should be noted that there is a considerable difference between rotational structure narrowing caused by pressure and that caused by motional averaging of an adiabatically broadened spectrum [158, 159]. In the limiting case of fast motion, both of them are described by perturbation theory, thus, both widths in Eq. (3.16) and Eq (3.17) are expressed as a product of the frequency dispersion and the correlation time. However, the dispersion of the rotational structure (3.7) defined by intramolecular interaction is independent of the medium density, while the dispersion of the vibrational frequency shift (5 12) in (3.21) is linear in gas density. In principle, correlation times of the frequency modulation are also different. In the first case, it is the free rotation time te that is reduced as the medium density increases, and in the second case, it is the time of collision tc p/ v) that remains unchanged. As the density increases, the rotational contribution to the width decreases due to the reduction of t , while the vibrational contribution increases due to the dispersion growth. In nitrogen, they are of comparable magnitude after the initial (static) spectrum has become ten times narrower. At 77 K the rotational relaxation contribution is no less than 20% of the observed Q-branch width. If the rest of the contribution is entirely determined by... 

If the contribution of a polymer molecule to the viscosity of the solution is in reality proportional to the cube of its linear dimension, the intrinsic viscosity in a -solvent should be proportional to the square root of the molecular weight. The influence of intramolecular interactions on the configuration having been neutralized by this choice of solvent medium, it becomes possible to examine separately the hydro-dynamic aspects of the problem. 

The AGD/LogP algorithm [54, 55] is based on logP contributions of separate atoms, structural fragments and intramolecular interactions between different fragments. These contributions have been derived from an ACD/Labs internal database of over 18 400 structures for which one or more experimental log P values have been published. The log P increments are stored in the internal databases of logP contributions ... 

XLOGP [67, 68] is a further atom-additive method, as expressed by its almost exclusive use of atomic contributions. However, in contrast to pure atom-based methods correction rules are defined, to account for intramolecular interactions, which is typical for fragmental methods. 

The dependence on the nuclear positions is indicated by r and the dependence on the Drude positions is indicated by d. In Eq. (9-25) Ubond (r) is the intramolecular energy contribution from, typically, the bond lengths, valence angles, and dihedral angles, Ulj (r) is a Lennard-Jones 6-12 nonpolar contribution, Ueiect (r, d) represents all Coulombic interactions, atom-atom, atom-Drude, and Drude-Drude, and Useif (d) represents the atom-Drude harmonic bonds. The term Usey (d) arises from the harmonic spring separating the two charges and has the simple expression... 

Hendsch, Z. Tidor, B., Electrostatic interactions in the GCN4 leucine zipper substantial contributions arise from intramolecular interactions enhanced on binding, Prot. Sci. 1999, 8, 1381-1392... 

From our considerations above, we can see just how important the interactions of various amino acid side-chains are to the structure and shape of proteins. These interactions tend to be located inside the protein molecule, stabilizing a particular conformation and generating the overall shape as in a globular protein. However, it is obvious that there are also going to be many amino acid side-chains located on the surface of a protein, and these in turn will be capable of interacting with other molecules. These interactions will be intermolecular, rather than the intramolecular interactions that contribute to protein structure. 

Carbon-13 relaxation depends predominantly on intramolecular contributions, whereas proton relaxation is sensitive to inter-molecular as well as intramolecular interactions. However, by use of isotope dilution— the two types of interactions may be separated. Studies utilizing both nuclei can thus yield complimentary information. 

The special interaction terms are necessary to describe intramolecular interactions between different parts of the molecule that cannot be accounted for when considering the transfer of the isolated parts. Obviously, this type of approach has a big advantage in that it allows one to estimate a partition constant based solely on the compound s structure. Good results can be anticipated particularly in those cases where the partition constant of a structurally closely related compound is known, and thus only the contributions of the parts that are different between the two compounds have to be added and/or subtracted, respectively. The most advanced and most widely used method that is based on this concept is the structural group contribution method for estimating octanol-water partition constants. We will discuss this method in Chapter 7. 

The symbol ( )n denotes one mole of domains of any spin state with n molecules in each domain. Interactions between the domains, irrespective of the spin state, are neglected. The total energy of an individual complex molecule is considered to be composed of electronic and intramolecular vibrational contributions. In terms of the partition functions for these contributions the equilibrium constant K = xhs/O-xhs) may be formulated as... 

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