A class of orthogonal multifunctional lanthanide-titanium clusters, Ln₄Ti₉, was obtained by reacting 4-trifluoromethylbenzoic acid, isopropyl titanate, and Ln(OAc)₃·xH₂O under solvothermal conditions. These clusters can be used for the purification of colored dye wastewater and for high-performance X-ray scintillators. Specifically, the metal centers in the cluster nucleus of Ln₄Ti₉ are arranged in a near-planar manner, and the ligands are tightly wrapped around the cluster nucleus, which ensures the stability of the cluster in solution. In-depth exploration of the energy transfer pathways has demonstrated that the Eu₄Ti₉ structure possesses an efficient antenna effect and optimal energy level matching, exhibiting a bright red luminescence. Furthermore, Eu₄Ti₉ exhibits excellent X-ray scintillator performance, with a light yield of up to 11,677 photons∙MeV^-1 and a detection limit as low as 2.2 μGy∙s^-1, which is 2.5 times lower than the clinical standard for medical use (5.5 µGy∙s^-1). It also shows excellent radiation stability after 36 radiation cycles and enables low-dose X-ray imaging. Under white light irradiation of 60 mW·cm^-2, the rapidly generated ROS storm of Gd₄Ti₉ almost completely degraded methylene blue (MB), rhodamine B (RhB), and norfloxacin (NFX) in aqueous solution within 50 and 40 min, respectively, with degradation rates as high as 0.0216 min^-1, 0.0592 min^-1, and 0.0146 min^-1, respectively. This work applies a highly stable lanthanide-titanium cluster system in aqueous solution to the field of photocatalytic wastewater purification, specifically targeting colored dyes and antibiotics.

Regulating reaction conditions to manipulate the twisting angle or conformational changes of the molecular rotor modules in triangular-shaped aggregation-induced emission luminogens (AIEgens) can induce the formation of lanthanide metal-organic frameworks (Ln-MOFs) with 3,8-c, 3²,8-c, and 3³,11-c connected network structures, significantly enriching the 3-c connected network family. This work, to our knowledge, is the first to reveal that alterations in the twist angles of molecular rotor modules in triangular-shaped AIEgens can lead to a serial expansion of the family of topological networks based on 3-c connections. Surprisingly, both Eu-MOF and Tb-MOF display linear temperature responses with varying sensitivities in the high and low temperature regions, respectively, facilitating the construction of a dual-region ratiometric fluorescence thermometer. What is more noteworthy is that Tb-MOF can be easily and efficiently fabricated into thin films, maintaining stable and bright yellow-green luminescence even after multiple foldings, which demonstrates its excellent mechanical flexibility and processability potential. This study not only charts a new course for expanding the topological network structure of Ln-MOFs through dynamic AIEgens but also broadens the horizons for the optical applications of multifunctional Ln-MOFs emitters.