Fig. 7: Optical experiment with fluorescence spectrum.
From: Reductive dearomative arylcarboxylation of indoles with CO2 via visible-light photoredox catalysis

a Steady-state Stern–Volmer experiment of 4CzIPN and DIPEA, the luminescence of 4CzIPN was readily quenched by DIPEA. b Stern–Volmer fluorescence quenching experiments using 4CzIPN with DIPEA, 1 as well as 1 and Cs2CO3.