ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Explicit expressions for the DK and RK associated with the excitation of regular oligomers from their ground states to the Kth exciton state as functions of N, P, μ, μ∥, μt, and μr have been derived on the assumption that the only perturbation Vij to the N singly excited states results from exciton transfer between adjacent residues, V12. The DK relation predicts the occurrence of a perpendicularly polarized absorption band arising from μ⊥ and a parallel polarized band from μ∥ with maxima at K = [2(N + 1)/P] and 1, which are shifted from the monomer band by 2V12 cos(2π/P) and 2V12cos[π/(N + 1)], respectively. Overlapping of the bands, which may occur in oligomers, decreases rapidly with N, leaving two perfectly polarized bands in the polymer. Within each band which includes only a few levels near the maxima, the most probable transition may be associated with all of the intensity for very short chains but only 40.2-50% (⊥) and 80.9% (∥) as N → ∞ (polymer case). A relation was derived by which V12 may be simply calculated from μ, μr, μt, μ∥, a, and z. The nearest neighbor theory was compared with experiment by calculating a reasonable set of the relevant parameters which exactly account for known spectral shifts.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.360010305
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