Synthesis and Structural Studies of Poly(p-phenylenevinylene) Analogous Model Compounds

Abstract

Described is the synthesis and characterization of three poly(p-phenylenevinylene) (PPV) three-ring model compounds, one unsubstituted at the vinylene moiety (1) and two dicyanosubstituted compounds (2, 3), differing in the positions of their cyano groups. Single-crystal analyses of the two cyano-substituted compounds 2 and 3 show that introduction of cyano groups into alkyl-substituted PPV analogous compounds leads to remarkable torsion of the conjugated backbones unlike hexyloxy-substituted compounds. In the case of introducing it into the R-position as in 2, the torsion is distributed almost equally over the molecule. Introducing the cyano group into the -position as in 3 leads to a one-sided torsion between the inner phenylene ring and the vinylene-CN planes.

Threshold Temperature Sensors with Tunable Properties

“…Cyano-substituted oligo( p-phenylene vinylene) derivatives (cyano-OPVs, Figure 1) [37][38][39][40][41][42][43][44][45][46] are particularly suitable for this sensing scheme since they often exhibit groundstate charge-transfer interactions [34] as well as excimer emission. [37] Further, their optical characteristics and solubility in different host polymers are readily controlled via the nature of substituents attached to the aromatic rings, and their good thermal stability allows for incorporation of the dyes into polymers by conventional melt-processing techniques.…”

Stimuli‐Driven Assembly of Chromogenic Dye Molecules: a Versatile Approach for the Design of Responsive Polymers

“…While many different types of excimer-forming dyes are useful in the context of the here-discussed sensor polymers (vide infra), much of the published work on the subject has been based on cyano-substituted oligo(p-phenylene vinylene)s (cyano-OPVs, Figure 5.2), which exhibit particularly attractive features [24][25][26][27][28][29][30][31][32][33]. Cyano-OPVs often exhibit a strong tendency toward excimer formation and display remarkably large differences (up to 140 nm) between the emission maxima of molecular solutions and solid state [24].…”

Electronic Structures and Spectroscopy of Luminescent para‐Phenylenevinylene Oligomers

“…1 Then a great interest in the properties of conjugation polymers, such as luminescence and conductivity, has been stimulated. 2,3 Substituents, 4 solvents 5 and some inorganic compounds 2 have some effects on these properties. The substituents on the compounds may affect the optical and electronic behavior of the compounds due to the distortion of the conjugation backbone caused by their electronic characters and steric effects.…”

“…The substituents on the compounds may affect the optical and electronic behavior of the compounds due to the distortion of the conjugation backbone caused by their electronic characters and steric effects. 4 Pu et al 6 have prepared the triphenylamine-substituted polymers showing high photo-luminescent efficiency as a film. Jin et al 7 have found that the HOMO and LUMO energy levels, the electronic and optical properties for some copolymers could be changed with the change of the structures on the main chain and the groups on the side chain.…”