Fluorescence Enhancement by Symmetry Breaking in a Twisted Triphenylene Derivative

Jack W. Levell, Arvydas Ruseckas, John B. Henry, Yi Wang, Andrew D. Stretton, Andrew R. Mount, Trent H. Galow, Ifor D. W. Samuel

Research output: Contribution to journalArticlepeer-review

Abstract

1,4,5,8,9,12-Hexamethyltriphenylene (HMTP) shows a high photoluminescence quantum yield (PLQY) of 31% in the solid state, making it of interest for luminescence applications. The detailed photophysical properties of HMTP have been investigated by using time-resolved and steady-state luminescence, PLQY, and molar absorption coefficient measurements. An enhancement of the transition dipole moment for fluorescence and absorption was demonstrated compared to the case of unsubstituted triphenylene, which resulted in a 20-fold increase in the radiative decay rate. This is attributed to a breaking of triphenylene symmetry as a result of the necessarily twisted structure induced by steric crowding. In addition, it was shown that HMTP shows similar photoluminescence energies in solution, powder, and film, indicating a reduced. propensity for intermolecular pi-stacking compared to the case of triphenylene, as a result of this twisted structure. This work also develops a method for calculating the photoluminescence quantum yield of powders by using a calibrated photodiode in combination with an uncalibrated CCD spectrometer.

Original languageEnglish
Pages (from-to)13291-13295
Number of pages5
JournalThe Journal of Physical Chemistry A
Volume114
Issue number51
DOIs
Publication statusPublished - 30 Dec 2010

Fingerprint

Dive into the research topics of 'Fluorescence Enhancement by Symmetry Breaking in a Twisted Triphenylene Derivative'. Together they form a unique fingerprint.

Cite this