for both E to Z and Z to E photoisomerization reactions, revealing good efficiencies of 9% for the former and 26% for the latter (for details see the Supporting Information). These values render PAT photoswitch 1 into an outstanding performer in the context of double bond photoisomerizations in general and of indigoid photoswitches in particular, not to mention the unprecedented low energy light that drives both photoisomerizations in this case. To gain insights into the photostability 15 cycles of reversible photoswitching to the pss at the two wavelengths of 780 nm and 590 nm were conducted showing no discernible photodegradation of PAT 1 (Figure ).