Pentadecamer 2,5-Dipropoxy-1,4-phenylenevinylene

Abstract

The conjugated, all‐(E)‐configured pentadecamer 2,5‐dipropoxy‐1,4‐phenylenevinylene 1j was prepared by a multistep synthesis on the basis of hydroquinone. The procedure consists of a general method for the repetitive extension of oligo(phenylenvinylene) chains by two styryl units (7a ⇄ 10 ⇄ 12 ⇄ 14). The relatively rigid oligomer 1j represents a molecular wire of about 100 Å. The absorption of 1j provides a proof for the convergence theory for electronic properties of conjugated oligomers with increasing number of repeat units. The corresponding conjugated polymer 1p with the same substitution matches the values which were extrapolated from the oligomer series 1a−1j. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

Impact of Donor–Acceptor Functionalization on the Properties of Linearly π-Conjugated Oligomers: Establishing Quantitative Relationships for the Substituent and Substituent Cooperative Effect Based on Quantum Chemical Calculations

“…In this work, we show along with other investigators 3,8,[10][11][12][13][14][15]25 , that the overall response of the properties of π-conjugated compounds to donor-acceptor substitution can be expressed by means of simple analytical expressions. In earlier work 27 , we also showed that part of the response of a given property can be ascribed to substituent cooperative effects, i.e.…”

“…However, in the case of the 13 C NMR chemical shifts we notice only marginal effect. The strongest cooperative effects are observed for the D-PA-A and A-PA-A oligomers.…”

“…Concepts such as Effective Conjugation Length (ECL) 8 , Confinement Length (CL) 9 or Delocalisation Length (DL) 9 , which address the issues related to the saturation of a particular property with respect to the conjugation length, emerged. At the same time, Quantitative Structure-Property Relationships (QSPR) that model the dependence of molecular properties on chain size and substitution pattern were established 3,8,[10][11][12][13][14][15][16][17][18][19][20][21][22] . In this context, Meier et al were able to express the dependence of the longest wavelength of absorption (λ max ) on chain length for donor-acceptor substituted polyacetylene 3 .…”

“…Brédas et al 3,8,[10][11][12][13][14][15] describing the response of these properties to chain length extension and to the substitution pattern. These expressions will show at what rate the substituent impact will vanish for a given type of backbone, and how rapidly the ECL for that particular property will be reached.…”

Defined‐length Carbon‐rich Conjugated Oligomers

“…11.1). The pentadecamer 2 ðn ¼ 15Þ, the highest known monodisperse OPV [2], has 8256 such conformers. Because of symmetry criteria, the number N is lower than 2 nÀ1 ¼ 2 14 ¼ 16384.…”