Photophysical and photochemical properties of corannulenes studied by emission and optoacoustic measurements, laser flash photolysis and pulse radiolysis

Photophysical and photochemical properties of corannulene (CA) and tetrabromocorannulene (TBCA) in solution were investigated as follows. Spectra, quantum yields and lifetimes of fluorescence in solution at 295 K, and spectra and lifetimes of phosphorescence in a rigid matrix at 77 K were determined. Phosphorescence at 295 K was observed from TBCA. Intersystem crossing yields were determined to be as large as 0.9 by optoacoustic techniques. Triplet–triplet absorption spectra were obtained by laser flash photolysis. Absorption spectra of the radical cation and anion of CA were obtained by pulse radiolysis techniques.