The photoinduced dynamics of a series ofterpyridine 4H-imidazole-ruthenium complexes, which constitutea new family of panchromatic dyes, is investigated. Thedynamics involves two excited states localized within the 4Himidazolesphere. Upon MLCT excitation, an excited state ispopulated, which is localized on the central part of the 4Himidazoleligand caused by its nonplanar conformation. Thepopulation of the second excited state is connected to aplanarization of the 4H-imidazole ligand as revealed byviscosity-dependent measurements, and the excess electroniccharge on the ligand is shifted to the terminal rings. The impact on the photoinduced dynamics of the electronic character of thesubstituent at the terminal rings and the protonation state of the 4H-imidazole ligand is studied. Significant changes in thelifetime of the excitation and alterations of the decay mechanism are observed depending on the interplay of the electroniccharacter of the substituent and ligand protonation. In a NMe2 substituted complex, the character of the substituent is changedfrom electron donating to electron withdrawing upon stepwise protonation, resulting in pH switchable decay mechanism.
Authors
- Maria Wachtler,
- Stephan Kupfer,
- prof. dr hab. Julien Guthmuller link open in new tab ,
- Sven Rau,
- Leticia Gonzalez,
- Benjamin Dietzek
Additional information
- Category
- Publikacja w czasopiśmie
- Type
- artykuł w czasopiśmie wyróżnionym w JCR
- Language
- angielski
- Publication year
- 2012
