Electronic Structure and Conformational

Three of the most direct and readily comprehensible measures of the electronic structure of a molecular system are optical absorption spectroscopy and the two branched of photoelectron spectroscopy, known as ultraviolet and X-ray photoelectron spectroscopy, or UPS and XPS. The XPS of polymers [51], the UPS of polymers [52], as well as both the XPS and UPS of conducting polymers [53] have been reviewed recently. The reader is referred to the literature for further details. It should be relatively obvious from the figures presented below, however, how the calculated band structure, the density-of-valence-states (DOVs) derived therefrom, and the corresponding experimental valence band spectra can be compared with one another. 

FIGURE 11. The band structure (E vs k) for planar poly thiophene [49]. 

FIGURE 12. Optical absorption spectra of a thin solid film of P30T [60]. 

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O.V. Shishkin, Molecular, electronic structure and conformational flexibility of the 1, 6-dihydropyrimidine, 4, 5-dihydrofuro[2, 3-d]pyrimidine and their oxo, imino and methylene derivatives. J. Mol. Struct. 385, 55-63 (1996)... 

D-A molecules relate to (i) the mechanism of the radiative and nonradiative charge recombination CT So, (ii) the electronic structure and conformation of the molecules in the fluorescent CT state and (iii) the role of the charge-transfer triplet states ( CT) in the intramolecular energy and electron transfer. 

The semi-empirical CNDO/2 method has been applied64 to an analysis of the electronic structure and conformation of disulphur decafluoride. The results, in good agreement with the available experimental data, enable the calculation of the electronic terms which determine the shape of the potential surface and a discussion of the electronic non-equivalence of the axial and equatorial fluorine atoms, the chemical bond strength, and the anomalous S—S bond length in the S2F10 molecule. 

The electronic structure and conformation of organic radicals can be measured. 

Using a novel NMR shift reagent, for example cobalt(III)meso-tetraphenyl porphyrin (CoTPP), the conformation of (3) is found to be a mixture of many conformations. Theoretical and experimental results revealed ring current shift for (3) <90MRC343>. Electronic structure and conformational properties of the amide linkage were studied in lactams based on MNDO calculations and photoelectron spectroscopy <85Mi 9l8-oi>. 

Using ab initio LCAO-MO calculations on alkyl formates as a basis, the electronic structures and conformations of polysaccharide esters have been interpreted. Acetate units were calculated to be 30° to the eclipsed position due to non-bonded interactions. ... 

D. A. Kleier and G. H. Weeks, THEOCHEM, 33, 25 (1986). Electronic Structure and Conformational Analysis of Paraquat in Three Oxidation States. 

A. ELECTRONIC STRUCTURE (AND CONFORMATION) OF THE NEUTRAL POLYMERS IN SOLUTION... 

Kobayashi, X, and Utsunomiya, C., Electronic structures and conformations of N-benzylidenea-milines. II. Photoelectron spectral study, Bull Chem. Soc. Jpn., 53, 2002, 1980. 

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