Non-AIE-type molecular photosensitizers (PSs) suffer from the aggregation-caused-quenching (ACQ) effect in an aqueous medium due to the strong hydrophobic and π–π interactions of their conjugated planes, which significantly hinders the enhancement of tumor photodynamic therapy (PDT). So far, some ionic PSs have been reported with good water-solubility, though the ACQ effect can still be induced in a biological environment rich in ions, leading to unsatisfactory in vivo delivery and fluorescence imaging performance. Hence, designing molecular PSs with outstanding anti-ACQ properties in water is highly desirable, but it remains a tough challenge for non-AIE-type fluorophores. Herein, we demonstrated a strategy for the design of porphyrin-type molecular PSs with remarkable solubility and anti-ACQ properties in an aqueous medium, which was assisted by quantum chemical simulations. It was found that cationic branched side chains can induce serious plane distortion in diphenyl porphyrin (DPP), which was not observed for tetraphenyl porphyrin (TPP) with the same side chains. Moreover, the hydrophilicity of the chain spacer is also crucial to the plane distortion for attaining the desired anti-ACQ properties. Compared to ACQ porphyrin, anti-ACQ porphyrin displayed type-I ROS generation in hypoxia and much higher tumor accumulation efficacy by blood circulation, leading to highly efficient in vivo PDT for hypoxic tumors. This study demonstrates the power of sidechain chemistry in tuning the configuration and aggregation behaviors of porphyrins in water, offering a new path to boost the performance of PSs to fulfill the increasing clinical demands on cancer theranostics.

Due to their excellent electronic and optical properties, porphyrins are extensively studied conjugated macrocycles in supramolecular chemistry for assembling functional nanomaterials. Although the aggregation of monomers plays a significant role in driving the self-assembly process into ordered nanostructures, it remains a challenge for tuning the self-assembling behavior of porphyrins through molecular structure modifications, especially in aqueous solutions. In the present work, two novel water-soluble porphyrin derivatives were synthesized by introducing cationic linear side chains into the π-conjugated core for phosphate-templated assembly through electrostatic interactions. It was found that the stacking patterns (H- or J-type aggregation) of porphyrins could be tuned by varying the number of side chains, which are associated with dramatic morphological change. The cytotoxicity and photodynamic properties of the J-aggregation-driven nano-assemblies were also investigated for the purpose of anti-cancer treatment. This study demonstrates a facile and effective strategy to regulate the aqueous self-assembling behavior of porphyrins that can impact the structure and properties of assembly, which will be of great benefit to the design and synthesis of functional nanomaterials for specific applications.

In the molten slag system of CaO–SiO2–Al2O3, F− will replace part of the bridging oxygen in the Al–O network as bridging fluorine. The electronegativity of fluoride ions is greater than that of oxygen ions. By maintaining the molar number of metal cations, and using an equimolar amount of CaF2 to replace CaO, i.e., F− instead of O2−, the main focus of this research is whether one can inhibit the crystallization of the CaO–SiO2–Al2O3 slag system. In this paper, the techniques of single hot thermocouple technique, X-ray diffraction and Raman spectroscopy were used to analyze the crystalline properties, the crystalline phases and the molten slag structure. The results show that with the increase in the amount of equimolar CaF2 replacing CaO, the structure of Q0 decreases in prevalence, the structure of Q2, Al–F–Al and Al–O–Si with high polymerization increases in prevalence, the critical cooling rate decreases, the high temperature precipitation material of the sample changes from dicalcium silicate to gehlenite, and there will be CaF2 precipitation at low temperature.