The size of the liposomes remained the same before and after irradiation for both cases, implying that the liposomes could retain their structure under irradiation (Section S3). To characterize the photophysical properties and membrane integration of [1] 2+ , UV-vis absorption and emission spectra were recorded, and emission lifetime measurements were performed (see Figure and Table ). It was observed that [1] 2+ has two absorption bands in polar organic solvent (acetonitrile) at 330 nm and 410 nm, respectively, and one emission band at 540 nm, which decays with a lifetime of τ = 5.4 ± 0.5 ns, indicating a spin-allowed fluorescence from a singlet excited state.