Fastest thermal isomerization of an azobenzene for nanosecond photoswitching applications under physiological conditions

When speed is of the essence: After photoisomerization to its metastable cis form, an azo dye must undergo fast thermal isomerization back to the trans form to be suitable for real-time information transmission. The azopyrimidine shown has a relaxation time (τ) of just 40 ns under physiological conditions, as well as high biocompatibility, as determined by Escherichia coli growth in its presence (see picture).