Related Experiment Video
Updated: Jun 6, 2026

Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers
Published on: December 16, 2022
Oligothienoacenes versus oligothiophenes: impact of ring fusion on the optical properties
Juan Aragó1, Pedro M Viruela, Johannes Gierschner
1Instituto de Ciencia Molecular, Universidad de Valencia, Valencia 46980, Spain.
Abstract:
The impact of backbone rigidity on the optical properties of thiophene-based compounds is studied by analyzing in detail the geometrical, electronic, optical and vibronic features of a family of oligothienoacenes (nTAs) in comparison to non-fused α-oligothiophenes (nTs) by means of quantum-chemical calculations. Ring fusion in nTAs provokes a greater conjugation in the ground state. However, the change in the bond length alternation upon electronic excitation is very similar in both systems, which is also reflected in a similar evolution of the first optical transition energy with increasing oligomer size. Larger transition energies in nTAsvs.nTs arise from an electronic effect rather than from a structural one. nTAs present a normal mode predicted at ca. 500 cm(-1) which displays significantly higher Franck-Condon activity compared to nTs and which leads to pronounced differences in the optical spectra. Due to the rigid structure of nTAs, persistent mirror symmetry of absorption and emission is observed, very different to nTs.
More Related Videos
06:08Time-resolved Photophysical Characterization of Triplet-harvesting Organic Compounds at an Oxygen-free Environment Using an iCCD Camera
Published on: December 27, 2018
06:55Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
Published on: September 26, 2016
Related Concept Videos
Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Thermal and Photochemical Electrocyclic Reactions: Overview
UV–Vis Spectroscopy: Woodward–Fieser Rules
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group with both...