We also worked with resorufin ps3 and resazurin ps4 (Fig. ), both previously reported to form inclusion complexes of the PS2⊂C type . These two dyes are red-shifted even further; for example, the absorption maxima of the respective heterodimers with E-1 appear at 587 nm and 616 nm, with absorption expanding into the red spectral range. To our satisfaction, exciting the absorption bands on these heterodimers with orange and red light, respectively, resulted in a highly efficient E→Z isomerization of nearly all azoarene/PS combinations (Fig. and Supplementary Figs. and).