Energy spectra of poly(arylenevinylene)s containing different aromatic units

Abstract

The energy gaps of poly@-aryleneviny1ene)s with phenylene, naphthylene and anthrylene subunits are determined by extrapolating the UV/VIS spectroscopic data of the oligomers. The band structure of the three polymers was theoretically investigated. The topology-, geometry-and correlation-factors were determined upon which the energy spectra of this class of one-dimensional n-electron systems depend.

Excitonic Interactions in the Singlet and Triplet Excited States of Covalently Linked Zinc Porphyrin Dimers

“…Thus, even though the interporphyrin distance remains constant compared with yPyByPy, the value of Δ V p (S 1 ) increases by almost a factor of 2. Since the energy difference between an aromatic and a quinoidal structure is considerably smaller for anthracene than for benzene, substitution of a 9,10-anthrylene unit for the 1,4-phenylene group should favor the formation of a cumulenic quinoidal structure − and hence result in an increase in the coupling efficiency of the bridge, as is observed. Not only is the excess polarizability for yPyAyPy larger than that for yPyByPy, it is even larger than that for the much shorter bridge compound yPyyPy!…”

Synthesis and Properties of Molecular Rods. 2. Zig-Zag Rods

“…Oligo(1,4-naphthylenevinylene)s ([ n ] 235 ), oligo(9,10-anthrylenevinylene)s ([ n ] 236 ), and oligo(9,10-anthrylene-1,3-butadienylene)s ([ n ] 237 ) have been prepared by the Müllen group (Chart ). Similar synthetic methods should be applicable to the synthesis of all oligo(arylenevinylene)s. Oligomers up to the tetramer [ 4 ] 235 have been prepared by the Wittig and the McMurry reactions, while the Horner−Emmons olefination of the appropriate precursors yielded the oligomers [ n ] 236 . The Heck reaction does not give access to the oligomers 236 starting from 9,10-divinylanthracene, presumably because of the high steric hindrance around the reaction centers.…”

“…261 Several spectroscopic techniques were used to characterize the homologous series [n]232. A pro- 262 while the Horner-Emmons olefination of the appropriate precursors yielded the oligomers [n]236. 263 The Heck reaction does not give access to the oligomers 236 starting from 9,10divinylanthracene, presumably because of the high steric hindrance around the reaction centers.…”

Stimulated emission from vacuum-deposited thin films of a substituted oligo(p-phenylene vinylene)

“…Oligomers could possibly provide the required properties for electrically pumped lasing. Conjugated oligomers, which can serve as model compounds [6][7][8] for their parent polymers, have a welldefined chemical structure and the potential ability to form well-ordered molecular assemblies. It is well known that ordered conjugated organic materials exhibit low trap densities and high charge carrier mobilities, for both electrons and holes.…”