Partial electron densities

As is outlined for ene reactions of singlet oxygen in Scheme 15, the prototypical ene reaction starts with the electron delocalization from the HOMO of propene to the LUMO of X=Y. The delocalization from the HOMO, a combined n and orbital with larger amplitude on n, leads to a bond formation between the C=C and X=Y bonds. Concurrent elongation of the bond enables a six-membered ring transition stracture, where partial electron density is back-donated from the LUMO of X=Y having accepted the density, to an unoccupied orbital of propene localized on the bond. As a result, the partial electron density is promoted (pseudoex-cited) from the HOMO (it) to an unoccupied orbital (ct n ) of alkenes. This is a reaction in the pseudoexcitation band. 

Based on this conclusion one can introduce the concept of the partial electron density and draw its contour map in the plane just above and below, say one Bohr radius, the molecular plane [24, 29, 34]. Again for XVI and XII the results of g3 are given in Fig. 5, which is the contribution of the highest three occupied Huckel MO s. Note that due to the pairing theorem proved by Coulson and Rushbrooke [35] the n-electron densities on all the component carbon 2pn orbitals are the same and the contour map of the conventional electron density cannot differentiate any of the local aromaticity of alternant hydrocarbon molecules. 

With these definitions we get a correction for the one-center energy of the water oxygen atom due to partial electron density transfer to the acceptor orbital ... 

Abstract It is demonstrated that the profile changes of x-ray emission spectra of various molecules and solids are successfully reproduced by the local and partial electron density of states calculated by the DV-Aa molecular orbital method. Some successful examples of the materials characterization by way of comparing the measured x-ray spectra and the DV-Afa calculations are also demonstrated. 

On the other hand gas molecules are electrically neutral. Upon entering the solid they exchange partial electron density 5q with the matrix according to the equilibrium. 

The electronic transitions in triiodide between occupied and excited orbitals make contributions to bands at 376, 352 and 258 nm. The transfer of partial electron density from the carboxyl group to the excite orbital of U causes the appearance of... 

FIG U RE 20.3 Total and partial electronic densities of states calculated for LijNH, LijCaNj, and LijCafNHlj. 

As the degree of the carbide saturation with H was increased, the authors observed a weakening of the emission from the metallic band. This may be attributed to partial electronic density transfer from the M-M bonds to the M-H bonds. 

Partial Electron Density Distribution in the 2-Propenyl (Allyl) System... 

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