Deferasirox, ExJade, is an FDA-approved iron chelator used for the treatment of iron overload. In this work, we report several fluorescent deferasirox derivatives that display unique photophysical properties, i.e., aggregation-induced emission (AIE), excited state intramolecular proton transfer, charge transfer, and through-bond and through-space conjugation characteristics in aqueous media. Functionalization of the phenol units on the deferasirox scaffold afforded the fluorescent responsive pro-chelator ExPhos, which enabled the detection of the disease-based biomarker alkaline phosphatase (ALP). The diagnostic potential of these deferasirox derivatives was supported by bacterial biofilm studies.

Here we report the first series of in-plane thorium­(IV), uranium­(IV), and neptunium­(IV) expanded porphyrin complexes. These actinide (An) complexes were synthesized using a hexa-aza porphyrin analogue, termed dipyriamethyrin, and the nonaqueous An­(IV) precursors, ThCl4(DME)2, UCl4, and NpCl4(DME)2. The molecular and electronic structures of the ligand, each An­(IV) complex, and a corresponding uranyl­(VI) complex were characterized using nuclear magnetic resonance (NMR) and UV–vis spectroscopies as well as single-crystal X-ray diffraction analysis. Computational analyses of these complexes, coupled to their structural features, provide support for the conclusion that a greater degree of covalency in the ligand–cation orbital interactions arises as the early actinide series is traversed from Th­(IV) to U­(IV) and Np­(IV). The axial ligands in the present An­(IV) complexes proved labile, allowing for the electronic features of these complexes to be further modified.

Phototheranostics constitute an emerging cancer treatment wherein the core diagnostic and therapeutic functions are integrated into a single photosensitizer (PS). Achieving the full potential of this modality requires being able to tune the photosensitizing properties of the PS in question. Structural modification of the organic framework represents a time-honored strategy for tuning the photophysical features of a given PS system.Here we report an easy-to-implement metal selection approach that allows for fine-tuning of excited-state energy dissipation and phototheranostics functions as exemplified by a set of lanthanide (Ln = Gd, Yb, Er) carbazole-containing porphyrinoid complexes. Femto-and nanosecond time-resolved spectroscopic studies, in conjunction with density functional theory calculations, revealed that the energy dissipation pathways for this set of PSs are highly dependent on the energy gap between the lowest triplet excited state of the ligand and the excited states of the coordinated Ln ions. The Yb complex displayed a balance of deactivation mechanisms that made it attractive as a potential combined photoacoustic imaging and photothermal/photodynamic therapy agent. It was encapsulated into mesoporous silica nanoparticles (MSN) to provide a biocompatible construct, YbL@MSN, which displays a high photothermal conversion efficiency (η = 45%) and a decent singlet oxygen quantum yield (Φ Δ = 31%). Mouse model studies revealed that YbL@MSN allows for both photoacoustic imaging and synergistic photothermal-and photodynamic-therapy-based tumor reduction in vivo. Our results lead us to suggest that metal selection represents a promising approach to fine-tuning the excited state properties and functional features of phototheranostics.

A new mixed hexaphyrin, pyrihexaphyrin (0.1.0.0.1.0) (1), was prepared via an acid catalyzed cyclization between 5,5′-(pyridine-2,6-diyl)bis(pyrrole-2-carbaldehyde) (2) and terpyrrole (3).