Structural and electronic properties of poly(thiaheterohelicene)s

Area of Science:

• * Computational chemistry and materials science.
• * Investigation of conjugated polymers and heterocyclic systems.

Background:

• * Poly(thiaheterohelicene)s and related polymers exhibit unique helical structures.
• * Understanding their electronic and structural properties is crucial for materials applications.

Purpose of the Study:

• * To investigate the structural and electronic properties of model oligomers of poly(thiaheterohelicene)s.
• * To explore the relationship between aromaticity and electronic transitions in these helical polymers.

Main Methods:

• * Application of quantum chemical methods, specifically density functional theory (DFT) calculations.
• * Analysis of geometrical parameters and electronic transitions (pi-pi*) in model polymer oligomers.

Main Results:

• * DFT calculations show good agreement with experimental data for helical structures.
• * Poly(methyl-sulfonium) exhibits enlarged C-C bond lengths in thiophene rings, reducing aromaticity.
• * A direct relationship was established between reduced aromaticity and lower pi-pi* transition energy.

Conclusions:

• * Geometrical distortions in poly(methyl-sulfonium) significantly impact its electronic properties.
• * The study provides insights into the structure-property relationships of helical conjugated polymers.
• * Extrapolation of electronic transitions for infinite polymer chains offers predictive capabilities.