Emission switching of 4,6-diphenylpyrimidones: Solvent and solid state effects

Edward Adjaye-Mensah, Walter G. Gonzalez, David R. Bussé, Burjor Captain, Jaroslava Miksovska, James N. Wilson

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


The photophysics of 1-ethyl-4,6-bis(4-methoxyphenyl)-2(1H)-pyrimidone (1) and 1-ethyl-4,6-bis(4-(dimethylamino)phenyl)-2(1H)-pyrimidone (2) were investigated to determine the mechanisms of emission switching in response to protonation. UV-vis and steady state emission spectroscopy of the protonated and unprotonated forms across a range of solvents reveal the polarity dependence of the vertical excitation energies. Emission lifetimes and quantum yields show the solvent dependency of the excited states. Emission enhancements were observed in polyethylene glycol solutions and in the solid state (both thin film and single crystal), demonstrating the role of intramolecular rotation in thermal relaxation of the excited states. TD-DFT calculations provide insights into the excited state geometries and the role of intramolecular charge transfer. The collected data show that emission of diphenylpyrimidones can be modulated by four factors, including the identity of the electron-donating auxochrome, protonation state, solvent polarity, and viscosity.

Original languageEnglish (US)
Pages (from-to)8671-8677
Number of pages7
JournalJournal of Physical Chemistry A
Issue number34
StatePublished - Aug 30 2012

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry


Dive into the research topics of 'Emission switching of 4,6-diphenylpyrimidones: Solvent and solid state effects'. Together they form a unique fingerprint.

Cite this