New porphyrin photosensitizers-Synthesis, singlet oxygen yield, photophysical properties and application in PDT.

This research on porphyrin-based photosensitizer system has a very important theoretical and practical significance in the photodynamic therapy (PDT) treatment of cancer. Based on this, in this article, a series of porphyrin derivatives were first designed and synthesized, and a "push-pull" porphyrin photosensitizer with two symmetrical ethanethioate groups was finally constructed. Based on the characterization of their chemical structures (1H and13C NMR, MS, IR, and UV-Vis spectroscopy) and the use of the density functional theory (DFT) and time-dependent DFT (TDDFT) to address the nature of the excited states as well as the dark/phototoxicity, the results have indicated the relationship between the porphyrin structure and properties. The experimental and theoretical UV-Vis absorption properties of porphyrins were discussed. The four porphyrin compounds synthesized all demonstrated a high capacity to generate singlet oxygen under long-wavelength (590 nm) light and low dark toxicity. Compared with the conventional porphyrin photosensitizers, P4 with a CT band (from 580 to 750 nm) is beneficial to the penetration of the light, presenting the potential for applications in PDT.

Synthesis of amphoteric fluorescent copolymers: materials exhibiting multicolor photophysical properties.

Six emissive amphoteric copolymers were prepared and characterized (1H NMR, DSC, steady-state UV-vis, and emission spectroscopy) in the paper. A system of multi-color emitters, composed of P1 (green and yellow), P2 (green), P3 (red), P4 (blue), P5 (yellow) and P6 (green and yellow), were presented. P5 showed multicolor fluorescence that belonged to the color-specially emissive system at different excitation wavelengths, and P6 exhibited color-correlated emission by efficient energy transfer.