Synthesis, Structure, and Characterization of 4,4'-(Anthracene-9,10-diylbis(ethyne-2,1-diyl))bis(1-methyl-1-pyridinium) Bismuth Iodide (C30H22N2)3Bi4I18, an Air, Water, and Thermally Stable 0D Hybrid Perovskite with High Photoluminescence Efficiency

4,4'-(Anthracene-9,10-diylbis(ethyne-2,1-diyl))bis(1-methyl-1-pyridinium) bismuth iodide (C₃₀H₂₂N₂)₃Bi₄I₁₈ (AEPyBiI) was obtained as a black powder by a very simple route by mixing an acetone solution of BiI₃ and an aqueous solution of C₃₀H₂₂N₂I₂. This novel perovskite is air and water stable and displays a remarkable thermal stability up to nearly 300 °C. The highly conjugated cation C₃₀H₂₂N₂ ²⁺ is hydrolytically stable, being nitrogen atoms quaternarized, and this accounts for the insensitivity of the perovskite toward water and atmospheric oxygen under ambient conditions. The cation in aqueous solution is highly fluorescent under UV irradiation (emitting yellow-orange light). AEPyBiI as well is intensely luminescent, its photoluminescence emission being more than 1 order of magnitude greater than that of high-quality InP epilayers. The crystal structure of AEPyBiI was determined using synchrotron radiation single-crystal X-ray diffraction. AEPyBiI was extensively characterized using a wide range of techniques, such as X-ray powder diffraction, diffuse reflectance UV-vis spectroscopy, Fourier transform infrared (FTIR) and Raman spectroscopies, thermogravimetry-differential thermal analysis (TG-DTA), elemental analysis, electrospray ionization mass spectroscopy (ESI-MS), and photoluminescence spectroscopy. AEPyBiI displays a zero-dimensional (0D) perovskite structure in which the inorganic part is constituted by binuclear units consisting of two face-sharing BiI₆ octahedra (Bi₂I₉ ^3- units). The C₃₀H₂₂N₂ ²⁺ cations are stacked along the a-axis direction in a complex motif. Considering its noteworthy light-emitting properties coupled with an easy synthesis and environmental stability, and its composition that does not contain toxic lead or easily oxidable Sn(II), AEPyBiI is a promising candidate for environmentally friendly light-emitting devices.

Donor-Acceptor Hybrid Heterostructures: An Emerging Class of Photoactive Materials with Inorganic and Organic Semiconductive Components

Just as the heterojunctions in physics, donor-acceptor (D-A) heterostructures are an emerging class of photoactive materials fabricated from two semiconductive components at the molecular level. Among them, D-A hybrid heterostructures from organic and inorganic semiconductive components have attracted extensive attention in the past decades due to their combined advantages of high stability for the inorganic semiconductors and modifiability for the organic semiconductors, which are particularly beneficial to efficiently achieve photoinduced charge separation and transfer upon irradiations. In this review, by analogy with the heterojunctions in physics, a definition of the D-A heterostructures and their general design and synthetic strategies are given. Meanwhile, the D-A hybrid heterostructures are focused on and their recent advances in potential applications of photochromism, photomodulated luminescence, and photocatalysis summarized.

Photocatalytic Multielectron Reduction of Nitroarenes to Anilines by Utilizing an Electron-Storable Polyoxometalate-Based Metal-Organic Framework

A powerful approach to generate photocatalysts for the highly selective reduction of nitrobenzene using light as the driving force is a combination of photosensitizers and electron-storable components in a cooperative photocatalysis fashion. Herein, a new precious metal-free photocatalyst, {ZnW-TPT}, was prepared by incorporating a Zn-substituted monovacant Keggin polyanion [SiZnW₁₁O₃₉]^6- and a photoactive organic bridging link 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT) into a framework. In this structure, the direct coordination bond between [SiZnW₁₁O₃₉]^6- and the TPT ligand and the π-π interactions between TPT molecules help separate and migrate photogenerated carriers, which improves the photocatalytic activity of {ZnW-TPT}. The photoelectrochemical properties of {ZnW-TPT} were well studied by solid UV-vis absorption, fluorescence, transient photocurrent response, and electrochemical impedance spectroscopy tests. {ZnW-TPT} efficiently converts using hydrazine hydrate with 99% conversion and 99% selectivity for anilines under mild conditions.

A halogen bonding assembled hybrid copper halide framework as a promising hypotoxicity photodetector

The first halogen bonding assembled three-dimensional hybrid copper iodide was obtained by a facile and sustainable “All-in-One” synthesis strategy and shows great application potential as a hypotoxicity photodetector.

Encapsulating third donors into D-A hybrid heterostructures to form three-component charge-transfer complexes for enhanced electrical properties

D-A hybrid heterostructures are an emerging class of crystalline hybrid materials composed of semiconductive inorganic donors and organic acceptors. However, due to the steric effects of the inorganic coordination sites, it is difficult for the large organic molecules to form compact packing at the molecular level, resulting in the poor efficiency of photoinduced charge transfers. To achieve an effective carrier separation and transfer, herein we incorporated third donors into a copper(I) halide/thiazolo[5,4-d] thiazole D-A heterostructure to construct three novel three-component complexes (Me₂-Py₂TTz)Cu₄I₆·(I₂) (1), (Me₂-Py₂TTz)Cu₃I₅·(pyrene) (2) and (Me₂-Py₂TTz)Cu₃I₅·(perylene) (3) (Py₂TTz = 2,5-bis(4-pyridyl) thiazolo[5,4-d] thiazole), respectively. Due to the spatial distances as well as the orbital energies between the copper(I) halide and thiazolo[5,4-d] thiazole units bridged by third donors, they are excellent three-component charge-transfer complexes (CTCs) with enhanced electrical properties.

Conjugated-Polypyridine-Derivative-Derived Semiconductive Iodoplumbates with Tunable Architectures and Efficient Visible-Light-Induced Photocatalytic Property

By mediation of the pH values, three novel inorganic-organic iodoplumbate hybrids, [Me₃TPT][Pb₃I₉] [1; Me₃TPT = trimethyl-2,4,6-tris(4-pyridyl)-1,3,5-triazine], [Me₃TPT]₂[Pb₉I₂₄] (2), and [Me₃TPT]₂[Pb₁₉I₄₄] (3), have been achieved under solvothermal conditions. The large conjugated in situ N-alkylation polypyridine derivatives act as structure-directing agents and electron acceptors, making the materials feature adjustable structural variations with 0D, 1D, and 2D structures and a potential semiconductive performance with narrow energy gaps (1.72, 1.80, and 1.78 eV for 1-3, respectively), which result in their efficient photocatalytic activity under visible-light irradiation. Theoretical calculation reveals that the conjugated organic moieties greatly contribute to the conduction band, leading to narrow band gaps. It is expected that the work will contribute to the exploitation of novel semiconducting halometallates by employing conjugated organic species as structure-directing agents.

Transition-Metal-Complex-Directed Synthesis of Hybrid Iodoargentates with Single-Crystal to Single-Crystal Structural Transformation and Photocatalytic Properties

We synthesized and characterized three types of isostructural iodoargentates, [TM(phen)₃]Ag₂I₄·3DMF (TM = Co (1), Ni (2), Zn (3)), [TM(phen)₃]Ag₃I₅·DMF (TM = Co (4), Ni (5), Zn (6)), and [TM(phen)₃]₂Ag₈I₁₂·7DMF (TM = Co (7), Ni (8), Zn (9)) (phen = 1,10-phenanthroline, DMF = dimethylformamide) using transition-metal (TM) complexes as the structure-directing agents. Compounds 1-3 and compounds 4-6 feature zero-dimensional anionic [Ag₄I₈]^4- and [Ag₆I₁₀]^4- clusters, respectively. All of the [TM(phen)₃]²⁺ cations in compounds 1-6 are arranged into a two-dimensional (2D) (6,3) net layer. Interestingly, compounds 1-3 are kinetically unstable in the mother solution, and they can be converted to compounds 4-6 via irreversible single-crystal to single-crystal transformation processes, respectively, with distinct changes in the crystal morphology and structure. Compounds 7-9 feature one-dimensional (1D) zigzag chains constructed from [Ag₈I₁₂]^4- units. The UV-vis diffuse reflectance measurements demonstrate that compounds 1-9 possess the characteristics of semiconductors with band gaps of 2.58-2.71 eV and visible-light-irradiation-induced photocatalytic activities. Especially, compound 3 possesses higher photocatalytic degradation activity toward crystal violet (CV) and rhodamine B (RhB) in comparison to P25 under identical conditions. Moreover, the mechanism study reveals that the TM complex cations make a great contribution to the photocatalytic activity.

Transition metal complex dye-sensitized 3D iodoplumbates: syntheses, structures and photoelectric properties

The first types of transition metal complex cationic dye-sensitized 3D hybrid porous iodoplumbates exhibiting outstanding visible light-driven photoelectric properties.