Induced bond charge

Why interaction between charged fragments of the same sign shows the same features than bonds Charge-induced bonds... 

T system, the PPP a—-tt method (133). The -tt and a net charges and bond orders of thiophene and thiazole are compared in Table 1-5. Whatever the method considered the variation of the indices occurs in the same sense when passing from thiophene to thiazole the replacement in the 3-position of a carbon atom by a nitrogen induces... 

It is probable that the negative charge induced by these three electrons on FeMoco is compensated by protonation to form metal hydrides. In model hydride complexes two hydride ions can readily form an 17-bonded H2 molecule that becomes labilized on addition of the third proton and can then dissociate, leaving a site at which N2 can bind (104). This biomimetic chemistry satisfyingly rationalizes the observed obligatory evolution of one H2 molecule for every N2 molecule reduced by the enzyme, and also the observation that H2 is a competitive inhibitor of N2 reduction by the enzyme. The bound N2 molecule could then be further reduced by a further series of electron and proton additions as shown in Fig. 9. The chemistry of such transformations has been extensively studied with model complexes (15, 105). 

Spectroscopic techniques look at the way photons of light are absorbed quantum mechanically. X-ray photons excite inner-shell electrons, ultra-violet and visible-light photons excite outer-shell (valence) electrons. Infrared photons are less energetic, and induce bond vibrations. Microwaves are less energetic still, and induce molecular rotation. Spectroscopic selection rules are analysed from within the context of optical transitions, including charge-transfer interactions The absorbed photon may be subsequently emitted through one of several different pathways, such as fluorescence or phosphorescence. Other photon emission processes, such as incandescence, are also discussed. 

Electrostatic interactions encompass ionic, dipole-t ii ., dipole-induced dipole, or charge-induced dipole interactions. No fo-aial elaboration of the appropriate equations will be given here becujis the alkyl bonded stationary phases most commonly used in RPC are no, expected... 

Klahn, M., Schlitter, J., and Gerwert, K. (2005). Theoretical IR spectroscopy based on QM/MM calculations provides changes in charge distribution, bond lengths, and bond angles of the GTP ligand induced by the Ras-protein. Biophys. J. 88, 3829-3844. 

The induced dipole moment depends on the electric field strength and the structure of the molecule. Charge-induced dipole interactions occur between a charged ion and polarized molecules. A molecule possessing conjugated double bonds is readily polarized. Examples of solutions due to the dipole-induced dipole interaction are benzene in methanol, chloral hydrate in CC14, and phenol in mineral oil. 

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