Polarized Laser Switching with Giant Contrast in MOF‐Based Mixed‐Matrix Membrane

Abstract

Nonlinear optical (NLO) switch materials have attracted considerable attention in photonics. Although various materials based on complex structural transitions have been developed extensively, the studies on light‐driven up‐conversion laser switches are rare, which have advantages including easy operations at room temperature and high contrasts. Here, the concept of photoswitch building unit is proposed to construct a novel sandwich‐like mixed‐matrix membrane. Dye@metal‐organic framework (MOF) crystals and spirooxazine are regarded as the laser emission and absorption units, followed by their hierarchical encapsulation into the polydimethylsiloxane carrier unit. Excited MOF microcrystals exhibit two‐photon pumped lasing anisotropy, with an ultrahigh degree of linear polarization (≈99.9%). Photochromic molecules can be interconverted by the external ultraviolet stimulus, causing sharp absorption‐band variations and inducing the laser emission or quenching. Such up‐conversion polarized laser switch material is reported for the first time. Record‐high NLO contrast (≈6.1 × 104) among the solid‐state NLO switch materials can be obtained through simultaneously controlling the ultraviolet irradiation and the emission‐detected polarization direction at room temperature.

Precise Design and Deliberate Tuning of Turn-On Fluorescence in Tetraphenylpyrazine-Based Metal−Organic Frameworks

“…As an important branch of luminescent materials, organic fluorescent materials have gained extensive attention owing to their huge application prospects [1][2][3]. However, most organic fluorescent molecules undergo fluorescence quenching, particularly in the solid state, resulting in the decreased quantum yield (QY), which greatly interferes their development in the fields of fluorescent applications owing to the aggregation-caused quenching (ACQ) [4][5][6][7].…”

Tunable NIR Lasing in MOF for Multi‐Level Complex Photonic Barcodes

“…Compared with the colorless ZJU-67 crystal, the as-prepared hybrid crystals exhibit purple and cyan appearances, corresponding to LDS-722@ZJU-67 and LDS-798@ZJU-67. According to our previous work, [27,34] due to the size match between the dye molecules and MOF pores, the linear dye molecules are speculated to align along 1D channels based the strong ionic interaction and pore confinement (Figure 2a). This speculation can be further confirmed by the crystallographic evidences that were obtained based on X-ray single crystal diffraction for ZJU-67 hybrid crystals (Figure S6, Supporting Information).…”

“…ZJU-67 is an anionic metal-organic framework, which is assembled by metal ion Mn 2+ and organic ligands 7-(4-carboxyphenyl) quinoline-3-carboxylic acid (H 2 CPQC). [34] Transparent regular hexagonal microcrystals were obtained after the solvothermal reaction. Figure 1b shows that the secondary building units (SBUs) of [Mn 3 O] 4+ are linked by the organic ligands.…”

Metal–Photoswitch Friendship: From Photochromic Complexes to Functional Materials

“…Moreover, MOFs allow for tailoring a framework environment through skeleton modification or wall grafting (Scheme ). ,− ,,,− ,,− Furthermore, photoswitch behavior can be tuned by incorporation of different guest molecules within framework cavities, including the presence or absence of solvent molecules of different polarity. ,,− Thus, in this section, we discuss the advantages of coordination of photoresponsive molecules to metals in well-defined crystalline scaffolds and the corresponding effects on physicochemical properties of the material, as well as outline the potential scientific gaps in this area.…”