Enhancing the ROS generation ability of a rhodamine-decorated iridium(iii) complex by ligand regulation for endoplasmic reticulum-targeted photodynamic therapy

Abstract

The endoplasmic reticulum (ER) is a very important organelle responsible for crucial biosynthetic, sensing, and signalling functions in eukaryotic cells. In this work, we established a strategy of ligand regulation...

The switchable phosphorescence and delayed fluorescence of a new rhodamine-like dye through allenylidene formation in a cyclometallated platinum(ii) system

“…Similar to the triplet excited state of organic dyes, rhodamine-based triplet excited state is commonly considered as a dark state and can be probed by transient absorption spectroscopy. [40][41][42][43][44] To the best of our knowledge, this is the first example for direct observation of the rhodamine-like originated phosphorescence in solution state at room temperature. In contrast, such phosphorescence was not found in deoxygenated solution of 2 in its ring-opened form.…”

“…The energy gap between the singlet and triplet states (Δ S-T ) of about 0.39 eV, estimated from the on-sets of fluorescence and phosphorescence energies, molecules in comparable Δ S-T values were reported to exhibit TADF. 59,60 With reference to other related studies on the rhodaminecontaining transition metal systems, [41][42][43][44] transient absorption (TA) spectroscopy is a valuable tool to probe the 3 IL of rhodamine. In order to verify the excited state nature, nanosecond transient absorption (TA) spectroscopies of 1 and 2 in their ring-opened forms were investigated with the excitation of 355 nm pulsed laser.…”

“…Our group has recently developed a versatile strategy to generate a rhodamine triplet state as organelle-targeting photosensitizers for efficient PDT through the ligation of rhodamine tethered chelate into transition metal systems. 43,44 Such long-lived triplet excited state of rhodamine is commonly a dark state in room temperature which can only be observed by the transient absorption spectroscopy.…”

“…We have been devoted to the exploration of possible combinations of transition metal complexes with photoswitchable and chemo-switchable units, such as photochromic diarylethenes (DTE) [22][23][24] and rhodamine-based derivatives, [43][44][45][46][47][48] respectively. As an extension of our ongoing interests in the controllable luminescence from the transition metal systems, our previous results prompted us to design and investigate novel rhodamine-based cyclometallated platinum(II) complexes.…”

BSA-encapsulated cyclometalated iridium complexes as nano-photosensitizers for photodynamic therapy of tumor cells

“…[21][22][23][24] Benet from the development of chemical synthesis, many types of photosensitizers have been developed. Among them, noble metal complex photosensitizers have attracted great attention, such as ruthenium complexes, 25,26 platinum complexes, 27,28 iridium complexes, 29,30 etc. Iridium Ir(III) complexes possess higher intersystem crossing efficiency and better photobleaching resistance than some organic photosensitizers.…”