Localized electron model summary

Localized Electron Model sp3 Hybridization sp Hybridization sp Hybridization dsp Hybridization d sp Hybridization The Localized Electron Model A Summary... 

In summary, all the experiments expressly selected to check the theoretical description provided fairly clear evidence in favour of both the basic electronic model proposed for the BMPC photoisomerization (involving a TICT-like state) and the essential characteristics of the intramolecular S and S, potential surfaces as derived from CS INDO Cl calculations. Now, combining the results of the present investigation with those of previous studies [24,25] we are in a position to fix the following points about the mechanism and dynamics of BMPC excited-state relaxation l)photoexcitation (So-Si)of the stable (trans) form results in the formation of the 3-4 cis planar isomer, as well as recovery of the trans one, through a perpendicular CT-like S] minimum of intramolecular origin, 2) a small intramolecular barrier (1.-1.2 kcal mol ) is interposed between the secondary trans and the absolute perp minima, 3) the thermal back 3-4 cis trans isomerization requires travelling over a substantial intramolecular barrier (=18 kcal moM) at the perp conformation, 4) solvent polarity effects come into play primarily around the perp conformation, due to localization of the... 

In summary, electrons can be localized within an atomic boundary in a closed-shell interaction. They can also be separately localized within the inner or valence shells, but not to bonded regions which cross interatomic surfaces, nor, in general, to non-bonded regions which occupy only a portion of a valence shell, to yield the Lewis model of the localized electron pair. 

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