Jump to main content
Jump to site search

Issue 28, 2019
Previous Article Next Article

fs–ps Exciton dynamics in a stretched tetraphenylsquaraine polymer

Author affiliations

Abstract

A tetraphenylsquaraine was synthesized whose structure was elucidated by single crystal X-ray structure analysis. Unlike all known indolenine squaraines, the tetraphenylsquaraine shows an unusual nonplanar structure with the four phenyl groups pointing away from the squaric acid core in order to avoid steric congestion. This tetraphenylsquaraine was polymerized by a Yamamoto coupling to form a conjugated polymer with Xn = 38. The absorption spectra of this polymer are red-shifted compared to that of the monomer and show a J-type absorption band due to exciton coupling. Transient absorption spectra with fs-time resolution display a strong ground state bleaching signal with a peak on the red side rising concurrently with the decay of a peak on the blue side of an isosbestic point at 12 000 cm−1. This behavior is caused by energy transfer between two slightly different sections of the polymer with time constants of 0.3 and 2.6 ps. According to semiempirical calculations these different sections are stretched and slightly bent conformations of the polymer strand. Power dependent transient absorption measurements indicate exciton annihilation which also proves the excitons to be very mobile.

Graphical abstract: fs–ps Exciton dynamics in a stretched tetraphenylsquaraine polymer

Back to tab navigation

Supplementary files

Publication details

The article was received on 22 May 2019, accepted on 22 Jun 2019 and first published on 28 Jun 2019


Article type: Paper
DOI: 10.1039/C9CP02900A
Phys. Chem. Chem. Phys., 2019,21, 15346-15355

  •   Request permissions

    fs–ps Exciton dynamics in a stretched tetraphenylsquaraine polymer

    M. H. Schreck, L. Breitschwerdt, H. Marciniak, M. Holzapfel, D. Schmidt, F. Würthner and C. Lambert, Phys. Chem. Chem. Phys., 2019, 21, 15346
    DOI: 10.1039/C9CP02900A

Search articles by author

Spotlight

Advertisements