Fig. 1: Exploration of carbamate caging for amino-containing PS.

a Chemical structures of uncaged (1) and caged (2) nitrobenzoselenadiazoles. b Normalized absorbance spectra of compounds 1 (dark red) and 2 (gray, both at 200 μM in EtOH) with calculated extinction coefficients at 490 nm. Insets show pictographs of DMSO solutions of compounds 1 and 2 (both at 20 mM, DMSO). c Singlet oxygen generation (left) and fluorescence emission (right) of uncaged compound 1 (10 µM, red bars) and caged compound 2 (10 µM, gray bars) measured in EtOH. Compound 1 showed a relative singlet oxygen quantum yield (reference: Rose Bengal) of 55% in EtOH (520 nm, 0.4–0.5 mW cm⁻²). Singlet oxygen generation for compounds 1 and 2 was compared in relative fluorescence units (RFU) by monitoring the fluorescence emission (525 nm) of singlet oxygen sensor green (SOSG, 2.5 µM in EtOH) before and after illumination (520 nm, 10 mW cm⁻²) for 10 min. Values presented as means and error bars as SEM (n = 15). d Electron density maps in molecular orbitals for compounds 1 and 2 calculated by DFT. Calculations were performed using the WB97XD functional with the cc-pVTZ basis set and the SMD solvent model in EtOH. The TD-DFT parameters specified the examination of 10 states, focusing on the first excited state. Source data (c) are provided as a Source Data file.