Efficient Intersystem Crossing in the Tröger's Base Derived From 4-Amino-1,8-naphthalimide and Application as a Potent Photodynamic Therapy Reagent.
Yingjie ZhaoKepeng ChenElif Akhuseyin YildizShujing LiYuqi HouXue ZhangZhijia WangJianzhang ZhaoAntonio BarbonHalime Gul YagliogluHuijian WuPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2020)
Intersystem crossing (ISC) was observed for naphthalimide (NI)-derived Tröger's base, and the ISC was confirmed to occur by a spin-orbital charge-transfer (SOCT) mechanism. Conventional electron donor/acceptor dyads showing SOCT-ISC have semirigid linkers. In contrast, the linker between the two chromophores in Tröger's base is rigid and torsion is completely inhibited, which is beneficial for efficient SOCT-ISC. Femtosecond transient absorption (TA) spectra demonstrated charge-separation and charge-recombination-induced ISC processes. Nanosecond TA spectroscopy confirmed the ISC, and the triplet state is long-lived (46 μs, room temperature). The ISC quantum yield is dependent on solvent polarity (8-41 %). The triplet state was studied by pulsed-laser-excited time-resolved EPR spectroscopy, and both the NI-localized triplet state and triplet charge-transfer state were observed, which is in good agreement with the spin-density analysis. The Tröger's base was confirmed to be a potent photodynamic therapy reagent with HeLa cells (EC50 =5.0 nm).
Keyphrases
- photodynamic therapy
- room temperature
- energy transfer
- solar cells
- single molecule
- ionic liquid
- fluorescence imaging
- high resolution
- induced apoptosis
- cell cycle arrest
- quantum dots
- molecular dynamics
- dna damage
- oxidative stress
- magnetic resonance imaging
- anti inflammatory
- cell proliferation
- endothelial cells
- contrast enhanced
- endoplasmic reticulum stress
- drug induced
- signaling pathway
- subarachnoid hemorrhage