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[Display omitted] • Complexes 1 , 2 and 3 exhibit reversible photochromic behavior. • Complexes 1 , 2 and 3 exhibit long-lived persistent phosphorescence. • Complex 2 exhibits excitation wavelength dependent fluorescence. • Three complexes show great potential in data encryption and anticounterfeiting. • 2 was fabricated in inkless printing performance and information transmission. Long persistent luminescence materials have wide application prospects in the fields of optical communication, sensors, and anticounterfeiting. Recently, some researchers have proved the feasibility of charge transfer effect in the construction of visible light excited room temperature phosphorescence (RTP) materials. However, materials with electronic effects require elaborate design to exhibit long-lived phosphorescence. Herein, a series of coordination compounds based on viologen ligand HL⋅Cl (4-carboxybenzyl)-4,4′-bipyridinium chloride) and Zn2+ with benzoic acid derivatives (o- , m- , p- phthalic acid) were reported. They exhibit not only reversible photochromic properties, but also long-lived persistent phosphorescence. Three complexes possess different structures through different auxiliary ligands with different optical physical properties. Complex 1 exhibits dynamic phosphorescence emission at low temperatures. Interestingly, we synthesized the first viologen complex (complex 2) with excitation wavelength dependent fluorescence, and the emission color gradually changed from blue to red with the increase of excitation wavelength. In addition, the applications of three complexes in data encryption and anticounterfeiting are further demonstrated. This work not only presents coordination compounds with dynamic afterglow materials, excitation wavelength- and time-dependent emission properties, but also provides a new strategy for the charge transfer effect in visible light-excited RTP materials. [ABSTRACT FROM AUTHOR]

In recent years, assembling 2D layered materials into three-dimensional (3D) architectures has become the research focus in catalysis fields. In this study, 3D porous g-C 3 N 4 @carbon (CN@C) microflowers composed of carbon-coated g-C 3 N 4 nanosheets were prepared by a facile bio-inspired method. At first, cyanuric acid-melamine (CAM) supermolecules were assembled into 3D microflowers with the mediation of sucrose molecules through a hydrothermal process, and then isomorphically converted into 3D CN@C microflowers upon calcination. By varying the saccharide species, it was found that the formyl groups of saccharide molecules and their self-polycondensation behavior could govern the CAM assembly and subsequent formation of microflower structure. The resultant CN@C microflowers exhibit high oxygen evolution reaction (OER) activity with a potential of 1.68 V at a current density of 10 mA cm −2 due to efficient mass and charge transfer, which is close to the reported value for the state-of-the-art metal catalyst IrO 2 /C (1.60 V, 0.1 mol L −1 KOH) and much superior to that of pure g-C 3 N 4 . [ABSTRACT FROM AUTHOR]