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Updated: Jul 25, 2025
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Published on: July 27, 2022
Exploring the Excited States of a Hexa-peri-hexabenzocoronene-Substituted Dipyridophenazine Ligand and Its Metal
Joseph I Mapley1, Jordan N Smith1, Georgina E Shillito1
1Department of Chemistry, University of Otago, P.O. Box 56, Dunedin 9016, New Zealand.
Abstract:
A hexa-peri-hexabenzocoronene (HBC)-substituted dipyridophenazine (dppz) ligand (dppz-HBC) and its corresponding rhenium [Re(CO)3Cl] and ruthenium [Ru(bpy)2]2+ complexes were synthesized and characterized. The interplay of their various excited states was investigated using spectroscopic and computational techniques. Perturbation of the HBC was seen through a broadening and decreased intensity of the HBC absorption bands that dominate the absorption spectra. A delocalized, partial charge transfer state was shown through emission (520 nm) in the ligand and rhenium complex and is supported by time-dependent density functional theory calculations. Transient absorption measurements revealed the presence of dark states with a triplet delocalized state populated in the ligand, while in the complexes, longer-lived (2.3-2.5 μs) triplet HBC states could be accessed. The properties of the studied ligand and complexes provide insight into the future design of polyaromatic systems and add to the rich history of dppz systems.
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