Sterically hindered diarylethenes with a benzobis(thiadiazole) bridge: photochemical and kinetic studies

Abstract

Based on benzobis(thiadiazole)-bridged diarylethenes, the exchanging rate between the main conformers in the ring-open form gradually slows down, offering the opportunity for isolating photoactive anti-parallel conformers. In the ring-closed state, the excess steric hindrance can disrupt the thermal bistability.

Dynamic Photoswitching of Electron Energy Levels at Hybrid ZnO/Organic Photochromic Molecule Junctions

“…However, the spectral features of the PA‐DAE in the valence region are not as pronounced as on ZnO(0001). This might be related to some damage due to long time exposure to the He I light during these photoemission measurements, which could give rise to relatively poor switching yield on ZnO(000‐1).…”

Electronic Properties of Optically Switchable Photochromic Diarylethene Molecules at the Interface with Organic Semiconductors

“…The fraction of 45 % DAE1‐o and 55 % DAE1‐c molecules (see fitting results in inset of Figure a) suggests that the back transfer (from DAE1‐o to DAE1‐c) was not completely reversible. This can be attributed to a manifold of causes, such as steric hindrance, radiation (UV, VUV) induced photoquenching, which prohibit such photoswitching of diarylethene molecules during light irradiation. Fully analogous photochromic switching was also observed for an ultrathin DAE1‐c layer with only 2 nm thickness (Figure S2a); the thickness was estimated by considering both XPS spectra and AFM images (Figure S2b and c).…”

Electronic Properties of Optically Switchable Photochromic Diarylethene Molecules at the Interface with Organic Semiconductors

“…However,i ti sn oteworthy that the spectrumi nt he valance region is still composed of both DAE1-o and DAE1cc ontributions, according to ad econvolution of measured UPS spectrum.T he fraction of 45 %D AE1-oa nd 55 %D AE1cm olecules (see fitting resultsi ni nset of Figure 2a)s uggests that the back transfer (from DAE1-o to DAE1-c) was not completely reversible. This can be attributed to am anifold of causes, such as steric hindrance, [17,[22][23] radiation( UV,V UV) induced photoquenching, [24] which prohibit such photoswitching of diarylethene molecules duringl ight irradiation. Fully analogous photochromic switching wasa lso observed for an ultrathin DAE1-cl ayer with only 2nmt hickness ( Figure S2a);t he thickness wase stimated by considering both XPS spectra and AFM images ( Figure S2b and c).…”

“…The fraction of 45% DAE1-o and 55% DAE1-c molecules (see fitting results in inset of Fig 2a) suggests that the back transfer (from DAE1-o to DAE1-c) was not completely reversible. This can be attributed to a manifold of causes, such as steric hindrance, [17,[22][23] radiation (UV, VUV) induced photoquenching, [24] which prohibit such photoswitching of diarylethene molecules during light irradiation. Fully analogous photochromic switching was also observed for an ultrathin DAE1-c layer with only of 2 nm thickness (Fig.…”