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Donor-acceptor (D-A) diaryl maleimides have received widespread attention due to their outstanding aggregation-enhanced emissive (AEE) properties. Herein, we report a novel rectangular D-A conjugated macrocyclic tetramaleimide with two phenyl and two 2,7-pyrene moieties as the sidewalls, while the maleimides as four corner linkers via dynamic and reversible Perkin reactions under thermodynamic control. Due to the sensitive D-A conjugation effects resulted from the multipole moments by four maleimides, such unique macrocycle exhibits unusual solvatochromic luminescent properties with a typical D-A charge transfer (CT) emission feature in the polar solvents, but pyrene-like emission characteristics in the nonpolar solvents regardless of the concentrations. A novel rectangular D-A conjugated macrocyclic tetramaleimide has been synthesized via dynamic and reversible Perkin reactions, which exhibits unusual solvatochromic luminescent properties. [Display omitted] • A facile synthetic pathway for rectangular D-A conjugated macrocyclic maleimides have been developed. • Dynamic covalent Perkin reactions have been demostrated to be an efficient synthetic pathway for macrocyclic maleimides. • The obtained macrocyclic maleimides exhibit unexpected solvatochromic luminescent properties. • The obtained macrocyclic maleimides exhibit a typical D-A charge transfer (CT) emission feature in the polar solvents. • The obtained macrocyclic maleimides exhibit pyrene-like emssions in carbon tetrachloride. [ABSTRACT FROM AUTHOR]

Iron-based metal organic frameworks (MOFs) are widely adopted to mediate heterogeneous photo-Fenton reaction, but poor charge separation efficiency in iron-oxo clusters of MOF usually results in the dull Fe(III)/Fe(II) transformation. In this study, ligand-to-cluster charge transfer (LCCT) excitations were first introduced to photo-Fenton process toward accelerating Fe(III)/Fe(II) transformation by constructing new iron-based MOF nanorods with porphyrin ligand (Fe-TCPP). Fe-TCPP with LCCT excitations showed a maximum kinetic constant of 0.23 min-1 for ciprofloxacin (CIP) degradation at neutral pH under visible light irradiation, which is remarkably better than most of the state-of-the-art photocatalysts. Experimental and theoretical analyses collaboratively verify that LCCT excitations within Fe-TCPP dramatically accelerate Fe(III)/Fe(II) transformation, which generate more ∙OH for quick CIP elimination. Additionally, this LCCT excitations strategy is also effective for the photo-Fenton-like system induced by copper-based MOFs. Our study presents a novel strategy to intensify MOFs based photo-Fenton/Fenton-like processes, upon which the high-efficiency contaminant removal is expected. [Display omitted] • LCCT excitations were first introduced to MOFs based photo-Fenton process. • Fe-TCPP with LCCT excitations displayed best antibiotic degradation performance. • LCCT excitations occurrence within Fe-TCPP was identified by different methods. • LCCT excitations within Fe-TCPP speed Fe(III)/Fe(II) transformation and ∙OH generation. [ABSTRACT FROM AUTHOR]