8-Methoxy-4-methylbenzo[g]coumarin

Uchiyama and Ohwada et al. have been reported that the unique fluorescence properties of a coumarin analog, 8-methoxy-4-methylbenzo[g]coumarin (MMBC). MMBC is almost nonfluorescent in aprotic solvents (e.g., fluorescence quantum yield Φ_f < 0.0003 in n-hexane), whereas it strongly fluoresces at long wavelengths (>450 nm) in protic solvents (e.g., Φ_f = 0.21 in methanol). In the protic solvents, MMBC has a large Stokes shift (>100 nm). MMBC also possesses high stability in the solvents shown in the figure, and facility in structural modification. These unique features are convenient for developments of new fluorogenic sensors and devices.