4.5 Article

Alternated quinoid/aromatic units in terthiophenes building blocks for electroactive narrow band gap polymers.: Extended spectroscopic, solid state, electrochemical, and theoretical study

Journal

JOURNAL OF PHYSICAL CHEMISTRY B
Volume 109, Issue 35, Pages 16616-16627

Publisher

AMER CHEMICAL SOC
DOI: 10.1021/jp0520300

Keywords

-

Ask authors/readers for more resources

We report here the synthesis of three novel 7-conjugated heterocyclic mixed trimers that contain two electrondonating 3,4-ethylenedioxy-2-thienyl (EDOT) units covalently attached to a central proquinoid electron accepting thienopyrazine moiety (two of these narrow-HOMO-LUMO gap D-A-D compounds also bear hexyl side chains attached either to the outermost positions of the EDOT end rings or to the beta positions of the pyrazine fused ring). The modification of the terthiophene structure upon EDO, pyrazine, and hexyl substitutions has been treated in detail with spectroscopic and theoretical arguments. Solid-state properties reveal the occurrence of short intramolecular contacts between heteroatoms of adjacent rings. The analysis of the structure of the 7-conjugated backbone of each molecule is consistent with a partial quinoid-like pattern which partially reverts to be subtly more aromatic depending on the topology of the positive inductive effect of the hexyl chains. This quinoidization is a consequence of the appearance of a D(EDOT)-> A(PyT)<- D(EDOT) intramolecular charge transfer which further polarizes the structure. The same chemical concepts have been applied to address their electrochemical behavior. The three mixed trimers exhibit amphoteric properties due to the combination of electron acceptor and donor groups. Given their relative low HOMO-LUMO energy gap, these trimers promise to be good candidates for obtaining polymers with significant low energy gap combining electroactivity.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.5
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available