Fig. 4

Photochemically induced isomerisation. CD (top) and UV–vis (bottom) spectral changes upon irradiation for 0, 10, 20, 40 and 60 s with λ_max = 365 nm light of a mixture of (E)-2 (5.0 × 10^‒4 M solution in CH₂Cl₂, 25 °C) and either 2 equiv. [Bu₄N]⁺[(S)-3]^‒ (CD, red line) or [Bu₄N]⁺[(R)-3]^‒ (CD, blue line). The appearance of a CD signal upon irradiation is caused by photogenerated formation of (Z)-2 and simultaneous induction of chirality by the chiral phosphate anion