Skip to main content
. 2018 May 1;115(38):9379–9384. doi: 10.1073/pnas.1712787115

Fig. 1.

Fig. 1.

Reversible photoswitching of unsubstituted azobenzene in water. (A) Synthesis of octahedral cage 1 from a triimidazole-based ligand and a cis-blocked Pd acceptor (34). (B) UV/blue light-induced isomerization of unsubstituted azobenzene 2. (C) Changes in the NMR spectrum of trans-2 (i) upon encapsulation within 1 (ii) and subsequent irradiation with UV light (iii) and blue light (iv). Spectrum i was recorded in (CD3)2SO and spectra ii–iv in D2O (400 MHz, 298 K). (D) X-ray crystal structure of (trans-2)2 ⊂ 1 (see also SI Appendix, Fig. S15). Color codes for all X-ray structures: C, gray; N, blue; O, red; F, green; Pd, brown sphere. Hydrogens, counterions, and solvent molecules are not shown for clarity. (E) Changes in the UV/Vis absorption spectrum of (trans-2)2 ⊂ 1 (black) following exposure to UV light (10 min, purple) and then to blue light (8 min, blue).