The Role of Torsional Dynamics on Hole and Exciton Stabilization in π‐Stacked Assemblies: Design of Rigid Torsionomers of a Cofacial Bifluorene

Authors

Denan Wang, Marquette UniversityFollow
Maxim Vadimovich Ivanov, Marquette University
Damian Kokkin, Marquette University
John Loman, Marquette University
Jin-Zhe Cai, Marquette UniversityFollow
Scott A. Reid, Marquette UniversityFollow
Rajendra Rathore, Marquette UniversityFollow

Document Type

Article

Language

eng

Publication Date

5-7-2018

Publisher

Wiley

Source Publication

Angewandte Chemie International Edition

Source ISSN

1433-7851

Abstract

Exciton and charge delocalization across π‐stacked assemblies is of importance in biological systems and functional polymeric materials. To examine the requirements for exciton and hole stabilization, cofacial bifluorene (F2) torsionomers were designed, synthesized, and characterized: unhindered (model) ^MeF2, sterically hindered ^tBuF2, and cyclophane‐like ^CF2, where fluorenes are locked in a perfect sandwich orientation via two methylene linkers. This set of bichromophores with varied torsional rigidity and orbital overlap shows that exciton stabilization requires a perfect sandwich‐like arrangement, as seen by strong excimeric‐like emission only in ^CF2 and ^MeF2. In contrast, hole delocalization is less geometrically restrictive and occurs even in sterically hindered ^tBuF2, as judged by 160 mV hole stabilization and a near‐IR band in the spectrum of its cation radical. These findings underscore the diverse requirements for charge and energy delocalization across π‐stacked assemblies.

Comments

Accepted version. Angewandte Chemie International Edition, Vol. 57, No. 27 (May 7, 2018): 8189-8193. DOI. © 2018 Wiley. Used with permission.

Recommended Citation

Wang, Denan; Ivanov, Maxim Vadimovich; Kokkin, Damian; Loman, John; Cai, Jin-Zhe; Reid, Scott A.; and Rathore, Rajendra, "The Role of Torsional Dynamics on Hole and Exciton Stabilization in π‐Stacked Assemblies: Design of Rigid Torsionomers of a Cofacial Bifluorene" (2018). Chemistry Faculty Research and Publications. 983.
https://epublications.marquette.edu/chem_fac/983