Fig. 4: Degradation byproduct.
From: The degradation mechanism of multi-resonance thermally activated delayed fluorescence materials
a Mass spectra (ESI, positive) of 100 μM 4 (Ar-saturated THF containing a 0.10 M tetrabutylammonium hexafluorophosphate supporting electrolyte) obtained before (top panel) and after (bottom panel) oxidative bulk electrolysis at an anodic potential of 1.04 V vs SCE. A Pt mesh and a Pt coil were used for the working and the counter electrodes, respectively. An Ag/AgNO3 pseudo reference electrode was used. The inset structures are the proposed chemical structures corresponding to the indicated m/z values. The inset black and red bars show the theoretical and observed m/z values, respectively. b 1H NMR (300 MHz, CD2Cl2) spectra of 4 before (top) and after (middle) the oxidative degradation, and the independently synthesized cyclization byproduct 4′ (bottom). c UV−Vis absorption spectra of 10 μM 4 (Ar-saturated THF containing 0.10 M tetrabutylammonium hexafluorophosphate) obtained during oxidative electrolysis (0−3 h) at an anodic potential of 1.04 V vs SCE. Arrows indicate spectral changes. The inset figure depicts the magnified view in the region 440−750 nm. d UV−Vis absorption spectra of 100 μM 4 reacted with 1 equiv [FeCl3] (Ar-saturated CH2Cl2). Arrows indicate spectral changes. The inset figure depicts the magnified view in the region 440−750 nm. e UV−Vis absorption (top) and absorption difference (bottom) spectra of an Ar-saturated THF 1.1 mM 4′ and a 0.10 M tetrabutylammonium hexafluorophosphate supporting electrolyte recorded upon application of an anodic potential of 0.80 V vs SCE (a Pt mesh working electrode, a Pt wire counter electrode, and an Ag/AgNO3 pseudo-reference electrode).
