Polymeric Iodoargentate Hybrids Incorporating Octakis- or Heptakis-Solvated Lanthanide Complexes: Syntheses, Crystal Structures, and Photocatalysis

Template Synthesis of Iodocuprate and Iodoargentate with Photocatalytic Activity and Second Harmonic Generation Efficiency

In virtue of the cationic tri(pyridin-4-yl)amine (TPA) derivatives acting as the templates, two iodometallates, [Me3HTPA]2[CuI3][Cu10I16] (1) and [Me3TPA][Ag5I8] (2), were constructed with different architectures. Compound 1 features a discrete [Cu10I16]6- cluster, which is further combined with [CuI3]2- and two [Me3HTPA]4+ moieties through electrostatic interactions to result in a 3D supramolecular framework. Two types of infinite Ag-I chains with different orientations are formed in iodoargentate 2, and adjacent chains, together with in situ N-methylated cations, are further aggregated into a final 3D supramolecule. The syntheses, crystal structures, and optical properties have been studied. Notably, compound 1 displays efficient visible-light-driven photocatalytic performance for the degradation of dye pollutants. The catalytic mechanism was investigated through radical trapping experiments as well as theoretical calculations. Moreover, both the iodocuprate and iodoargentate hybrids exhibit second harmonic generation (SHG) effects, which are comparable to and even better than that of KH2PO4, indicating that the iodometallate hybrids templated by TPA-based cations could potentially serve as new candidates for second-order nonlinear optics (NLO) materials.

Enhanced Circular Dichroism and Polarized Emission in an Achiral, Low Band Gap Bismuth Iodide Perovskite Derivative

Lead halide perovskites and related main-group halogenido metalates offer unique semiconductor properties and diverse applications in photovoltaics, solid-state lighting, and photocatalysis. Recent advances in incorporating chiral organic cations have led to the emergence of chiral metal-halide semiconductors with intriguing properties, such as chiroptical activity and chirality-induced spin selectivity, enabling the generation and detection of circularly polarized light and spin-polarized electrons for applications in spintronics and quantum information. However, understanding the structural origin of chiroptical activity remains challenging due to macroscopic factors and experimental limitations. In this work, we present an achiral perovskite derivative [Cu2(pyz)3(MeCN)2][Bi3I11] (CuBiI; pyz = pyrazine; MeCN = acetonitrile), which exhibits remarkable circular dichroism (CD) attributed to the material's noncentrosymmetric nature. CuBiI features a unique structure as a poly-threaded iodido bismuthate, with [Bi3I11]2- chains threaded through a cationic two-dimensional coordination polymer. The material possesses a low, direct optical band gap of 1.70 eV. Notably, single crystals display both linear and circular optical activity with a large anisotropy factor of up to 0.16. Surprisingly, despite the absence of chiral building blocks, CuBiI exhibits a significant degree of circularly polarized photoluminescence, reaching 4.9%. This value is comparable to the results achieved by incorporating chiral organic molecules into perovskites, typically ranging from 3-10% at zero magnetic field. Our findings provide insights into the macroscopic origin of CD and offer design guidelines for the development of materials with high chiroptical activity.

Syntheses, structures, photoelectric properties and photocatalysis of iodobismuthate hybrids with lanthanide complex cations

New iodobismuthate hybrids with lanthanide complex counter cations, [Ln(DMF)₈][Bi₂I₉] (Ln = La (1), Eu (2)) and [Tb(DMF)₈]₂[Bi₂I₉]₂ (3) (DMF = N,N-dimethylformamide), were prepared using solvated Ln(III) complexes formed in situ as structure-directing agents. The dimeric [Bi₂I₉]^3- anion moieties of compounds 1-3 are aggregated by two slightly twisted BiI₆ octahedra through face-sharing mode. The different crystal structures of 1-3 are due to the different I⋯I and C-H⋯I hydrogen bond interactions. Compounds 1-3 have narrow semiconducting band gaps at 2.23, 1.91 and 1.94 eV, respectively. Under Xe light irradiation, they exhibit steady photocurrent densities that are 1.81, 2.10 and 2.18 times higher than that of pure BiI₃, respectively. Compounds 2 and 3 exhibited higher catalytic activities than 1 in the photodegradation of organic dyes CV and RhB, which are attributed to the stronger photocurrent response derived from the redox cycles of Eu³⁺/Eu²⁺ and Tb⁴⁺/Tb³⁺.

Embedding Lanthanide Organic Polyhedra into Mesoporous Silica Nanoparticles for the Photocatalytic Degradation of Organic Dyes

Organic pollutants cause severe environmental problems because of their damage to human health and ecological systems. Photocatalytic degradation of persistent organic pollutants is of great importance to address these hazards. Herein, we report a lanthanide organic polyhedra-based hybrid material Gd₈ L₁₂ ⊂MSN with the capability of photocatalytic dye degradation. Gd₈ L₁₂ ⊂MSN was prepared by embedding the Gd₈ L₁₂ complex into mesoporous silica nanoparticles (MSNs) using a "ship-in-a-bottle" strategy. Photocurrent response tests revealed that this hybrid material is a potential semiconductor and could generate a rapid and steady photocurrent upon irradiation. Further dye degradation experiments indicated that it could photocatalyze the degradation of familiar organic dyes. Thereinto, compared with the critical Gd₈ L₁₂ complex, the hybrid material exhibited an acceleration of 2.4 times and realized reusability. This not only offers a potential advanced photocatalyst for degrading persistent organic pollutants, but also provides a strategy for the application of supramolecular materials in environmental science.

A four-fold three-dimensional zinc(II) coordination polymer based on 4,4′-bis(2-methyl-imidazolyl)biphenyl and 5-sulfoisophthalate ligands: synthesis, structure and properties

A Zn(II) coordination polymer, [Zn3(4,4′-BMIBP)3(SIP)2] n (1) (4,4′-BMIBP = 4,4′-bis(2-methyl-imidazolyl)biphenyl, H3SIP = 5-sulfoisophthalic acid) was hydrothermally synthesized and structurally characterized. Complex 1 has a (3,4)-connected binodal four-fold three-dimensional topology with a point symbol of {4·62·82·10}2{4·62}2{64·102}. It shows strong fluorescence emission in the solid state and efficient photocatalytic performances to degrade methylene blue (MB) under UV irradiation, the degradation of MB reaching 88% after 50 min.

A cadmium(II) coordination polymer with a fivefold interpenetrating diamondoid three-dimensional framework: synthesis, crystal structure, luminescence and photocatalytic properties

A novel three-dimensional (3D) Cd^II coordination polymer, namely, poly[[μ₂-4,4'-bis(2-methylimidazol-1-yl)-[1,1'-biphenyl]](μ₂-5-methylisophthalato)cadmium(II)], [Cd(C₉H₆O₄)(C₂₀H₁₈N₄)]_n or [Cd(MIP)(4,4'-BMIBP)]_n, (I), was synthesized by the hydrothermal method using 5-methylisophthalic acid (H₂MIP), 4,4'-bis(2-methylimidazol-1-yl)-[1,1'-biphenyl] (4,4'-BMIBP) and Cd(NO₃)₂·6H₂O, and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy and thermogravimetric analysis. Compound (I) exhibits a novel fivefold interpenetrating 3D diamondoid framework. Additionally, it shows fluorescence emission in the solid state and promising photocatalytic activities for the degradation of methylene blue (MB) in water at room temperature.

A fourfold interpenetrating three-dimensional cadmium(II) coordination polymer: synthesis, crystal structure and physical properties

A novel three-dimensional Cd^II coordination framework, namely, poly[{μ-bis[4-(2-methylimidazol-1-yl)phenyl] ether-κ²N³:N^3'}(μ-naphthalene-1,4-dicarboxylato-κ³O¹:O⁴,O^4')cadmium(II)], [Cd(C₁₂H₆O₄)(C₂₀H₁₈N₄O)]_n or [Cd(1,4-NDC)(BMIOPE)]_n, where 1,4-H₂NDC is naphthalene-1,4-dicarboxylic acid and BMIOPE is bis[4-(2-methylimidazol-1-yl)phenyl] ether, has been prepared and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy and thermogravimetric analysis. The compound displays a novel fourfold interpenetrating diamond-like network. In addition, it not only shows a strong fluorescence emission in the solid state, but also exhibits excellent photocatalytic activity for the degradation of methylene blue (MB) at room temperature.