Synthesis and photophysical properties of vertically π-expanded coumarins

Synthesis and luminescence properties of functionalized V-shaped bis-coumarin derivatives

“…coumarin fused with arenes/heteroarenes) have attracted considerable attention due to their extended conjugation and possible utility in photonics, and are expected to provide several advantageous features over corresponding simple coumarins, such as larger Stokes shift, longer emission wavelength and higher quantum yield. [21][22][23][24][25] Nitisha and P. Venkatakrishnan 24 exploited the Scholl cyclization method to synthesize various [g]-face areneannulated dipolar coumarins; these arene-annulated dipolar coumarins exhibited better absorption and emission characteristics (large Stokes shifts, tunable fluorescent quantum yields and high photostability) compared to simple coumarins or benzocoumarins. Heterocycle-fused coumarin derivatives are another important emerging class of p-extended coumarins, in which various heterocycle units are fused to the coumarin skeleton to cause the resulting compounds to exhibit promising or even unprecedented properties.…”

Polarized, V-Shaped, and Conjoined Biscoumarins: From Lack of Dipole Moment Alignment to High Brightness

“… 2 − 4 In addition to the features associated with their bioactivity, coumarins possess very interesting photophysical properties. 5 − 7 These compounds are highly desirable for applications in solar cells, 8 organic light-emitting diodes, 9 and laser dyes 10 due to their relatively simple, easily tunable structures, along with their high fluorescence quantum efficiencies, long decay times, and large Stokes shifts. Modification of the molecular structure of coumarins by extending the π-electron system strongly influences their electronic spectra.…”

“…This fact is mainly related to their very wide range of applications. Many groups of coumarins exhibit biological activity, including anti-inflammatory, antifungal, antibacterial, or dermal photosensitizing properties, that make them useful in the medicinal and pharmaceutical industries. − In addition to the features associated with their bioactivity, coumarins possess very interesting photophysical properties. − These compounds are highly desirable for applications in solar cells, organic light-emitting diodes, and laser dyes due to their relatively simple, easily tunable structures, along with their high fluorescence quantum efficiencies, long decay times, and large Stokes shifts. Modification of the molecular structure of coumarins by extending the π-electron system strongly influences their electronic spectra.…”

Temperature-Controlled Chemoselective Synthesis of Multisubstituted 4-Alkynyl/trans 4-Alkenyl Coumarins

“…They are accustomed in food and cosmetic industries as additives and also found to act as insecticides, optical brighteners, and fluorescent and laser dyes . Notably, various photophysical properties have been explored using the alkynyl- and alkenyl-substituted coumarin systems. Unsaturated lactone skeletons present in coumarins are traditionally synthesized by aldol or Knoevenagel, Pechmann, Perkin, Reformatsky, and Wittig condensations.…”