Torsional disorder in tetraphenyl [3]-cumulenes: Insight into the excited state quenching.

Autor: Bain D; Department of Chemistry and Chemical Biology, Cornell University, Ithaca 14850, United States., Chang J; Department of Chemistry and Chemical Biology, Cornell University, Ithaca 14850, United States., Lai Y; Department of Chemistry and Chemical Biology, Cornell University, Ithaca 14850, United States., Khazanov T; Department of Chemistry and Chemical Biology, Cornell University, Ithaca 14850, United States., Milner P; Department of Chemistry and Chemical Biology, Cornell University, Ithaca 14850, United States., Musser A; Department of Chemistry and Chemical Biology, Cornell University, Ithaca 14850, United States.
Jazyk: angličtina
Zdroj: Photochem [Photochem] 2024 Mar; Vol. 4 (1), pp. 138-150. Date of Electronic Publication: 2024 Feb 09.
DOI: 10.3390/photochem4010008
Abstrakt: Cumulenes are linear molecules consisting of consecutive double bonds linking chains of sp-hybridized carbon atoms. They have primarily been of interest for potential use as molecular wires or in other nanoscale electronic devices, but more recently other applications such as catalysis or even light harvesting through singlet fission have been speculated. Despite the recent theoretical and experimental interest, photoexcitation of cumulenes typically results in quenching on the picosecond timescale, and the exact quenching mechanism for even the simplest of [3]-cumulenes lacks a clear explanation. In this report, we perform transient absorption spectroscopy on a set of model [3]-cumulene derivatives in a wide range of environmental conditions to demonstrate that planarization of phenyl groups ultimately quenches the excited state. By restricting this intermolecular motion, we increase the excited state lifetime out to a few nanoseconds, strongly enhancing the photoluminescence and demonstrating an approach to stabilize them for photochemical applications.
Competing Interests: Conflicts of Interest The authors declare no conflict of interest.
Databáze: MEDLINE