charge transfer reactions

RL420 is an RNA-selective fluorescent covalent probe that binds covalently to the 2′-hydroxyl group of RNA via an acylimidazole-mediated reaction. RL420 has excitation/emission wavelengths of 420/452 nm, exhibits a 150-fold selectivity for RNA over DNA, and shows high labeling efficiency. RL420 can be used in studies related to in vitro RNA labeling, gel imaging, and blue fluorescent imaging of RNA in fixed cells (e.g., nucleoli) .

Iron (III) sulfate is a stable rhombohedral NASICON compound. Iron (III) sulfate can serve as a sodium ion intercalation host, enabling sodium ion intercalation and deintercalation via a single-phase mechanism relying on the Fe ²⁺/Fe ³⁺ redox couple. Iron (III) sulfate exhibits reversible electrochemical behavior and moderate polarization in cyclic voltammetry tests, and its charge transfer resistance changes during charge-discharge cycles. Iron (III) sulfate possesses a high redox potential, excellent rate capability, and long-cycle stability .

C-TPA is a fluorescent probe used for hypochlorite detection and bioimaging of lipid droplet polarity in cancer cells. For hypochlorite detection, when its derivative C-TPA-S is exposed to hypochlorite, an oxidative desulfurization reaction converts the thiocarbonyl group of C-TPA-S to the carbonyl group of C-TPA, thus restoring bright fluorescence from the almost non-fluorescent C-TPA-S. For bioimaging of lipid droplet polarity, the intramolecular charge transfer process between its Triphenylamine (HY-W011998) donor group and Coumarin (HY-N0709) acceptor group endows C-TPA with solvatochromism-it exhibits stronger fluorescence in less polar environments (such as lipid droplets in cancer cells) and weaker fluorescence in more polar environments (such as lipid droplets in normal cells), enabling the differentiation of cancer cells and cancer tissues from normal cells and normal tissues. The excitation wavelength of C-TPA is 405 nm, and the emission wavelengths used for cell and tissue imaging cover 425-475 nm and 500-550 nm; in solvents, its emission peak shifts from 494 nm in non-polar toluene to 528 nm in polar water .