Precise Single-Atom Modification of Hybrid Lead Chlorides for Electron Donor-Acceptor Effect and Enhanced Photocatalytic Aerobic Oxidation.

Hybrid lead halides show significant potential in photocatalysis due to their excellent photophysical properties, but the atomically precise modification of their organic component to achieve synergistic interactions with the lead halide units remains a great challenge. Herein, for the first time, we have employed the crystal engineering strategy to construct a class of single-atom-substituted hybrid lead halides with electron donor-acceptor (D-A) effect. The lead halide frameworks consist of 1D linear [PbCl] chains as inorganic building units and benzoxadiazole/benzothiadiazole/ benzoselenadiazole-funtionalized dicarboxylates as linkers.

Mixed-Layered Lead Halide Frameworks with High Stability and Efficient Room-Temperature Phosphorescence.

Room-temperature phosphorescent (RTP) materials play a crucial role in optical anticounterfeiting science and information security technologies. Ionically bonded organic metal halides have emerged as promising RTP material systems due to their excellent self-assembly and unique photophysical property, but their intrinsic instability largely hinders their advanced practical applications. Herein, we employ a coordination-driven synthetic strategy utilizing organocarboxylates for the synthesis of two isostructural layered lead halide frameworks.

Highly Stable MOF-Type Lead Halide Luminescent Ferroelectrics.

Lead halide molecular ferroelectrics represent an important class of luminescent ferroelectrics, distinguished by their high chemical and structural tunability, excellent processability and distinctive luminescent characteristics. However, their inherent instability, prone to decomposition upon exposure to moisture and light, hinders their broader ferroelectric applications. Herein, for the first time, we present a series of isoreticular metal-organic framework (MOF)-type lead halide luminescent ferroelectrics, demonstrating exceptional robustness under ambient conditions for at least 15 months and even when subjected to aqueous boiling conditions.

Solar-Driven Conversion of CO to C Products by the 3d Transition Metal Intercalates of Layered Lead Iodides.

Photocatalytic CO reduction to high-value-added C products presents significant challenges, which is attributed to the slow kinetics of multi-e CO photoreduction and the high thermodynamic barrier for C-C coupling. Incorporating redox-active Co/Ni cations into lead halide photocatalysts has high potentials to improve carrier transport and introduce charge polarized bimetallic sites, addressing the kinetic and thermodynamic issues, respectively. In this study, a coordination-driven synthetic strategy is developed to introduce 3d transition metals into the interlamellar region of layered organolead iodides with atomic precision.

Unveiling Advancements: Trends and Hotspots of Metal-Organic Frameworks in Photocatalytic CO Reduction.

Metal-organic frameworks (MOFs) are robust, crystalline, and porous materials featured by their superior CO adsorption capacity, tunable energy band structure, and enhanced photovoltaic conversion efficiency, making them highly promising for photocatalytic CO reduction reaction (PCORR). This study presents a comprehensive examination of the advancements in MOFs-based PCORR field spanning the period from 2011 to 2023. Employing bibliometric analysis, the paper scrutinizes the widely adopted terminology and citation patterns, elucidating trends in publication, leading research entities, and the thematic evolution within the field.

Promoting the formation of metal-carboxylate coordination to modulate the dimensionality of ultrastable lead halide hybrids.

Crystal engineering of metal halide hybrids is critical to investigate their structure-property relationship and advance their photophysical applications, but there have been limited efforts to employ coordination chemistry to precisely control the dimensionality of metal halide sublattices. Herein, we present a coordination-assembly synthetic strategy developed for the rational modulation of lead halide dimensionality, realizing the transition from 2D to 3D architectures. This manipulation is achieved by utilizing three organocarboxylates featuring the identical cyclohexane backbone unit.

Modulating Inorganic Dimensionality of Ultrastable Lead Halide Coordination Polymers for Photocatalytic CO Reduction to Ethanol.

Lead halide hybrids have shown great potentials in CO photoreduction, but challenging to afford C reduced products, especially using HO as the reductant. This is largely due to the trade-off problem between instability of the benchmark 3D structures and low carrier mobility of quasi-2D analogues. Herein, the lead halide dimensionality of robust coordination polymers (CP) was modulated by organic ligands differing in a single-atom change (NH vs.

Lead Halide Hybrids Templated by Two Coordinating Ligands for Enhanced and Stable Self-Trapped Emission.

Lead halide hybrids templated by coordinating ligands are a class of ultrastable broadband self-trapped emitters that overcome the stability problems of conventional ionically bound halide hybrids. However, enhancing their photoluminescence (PL) performances by crystal engineering remains a huge challenge. Herein, for the first time, we have successfully employed the synthetic strategy of two coordinating ligands to synthesize a series of layered lead halide coordination polymers, [PbX](chdc)(2,2'-bpy) (X = Cl/Br, chdc = -1,4-cyclohexanedicarboxylate), which involves chdc as a pillaring strut and 2,2'-bpy as a chelating ligand.

Catalytically active atomically thin cuprate with periodic Cu single sites.

Rational design and synthesis of catalytically active two-dimensional (2D) materials with an abundance of atomically precise active sites in their basal planes remains a great challenge. Here, we report a ligand exchange strategy to exfoliate bulk [Cu(OH)][OS(CH)SO] cuprate crystals into atomically thin 2D cuprate layers ([Cu(OH)]). The basal plane of 2D cuprate layers contains periodic arrays of accessible unsaturated Cu(II) single sites (2D-CuSSs), which are found to promote efficient oxidative Chan-Lam coupling.

Sequential Sol-Gel Self-Assembly and Nonclassical Gel-Crystal Transformation of the Metal-Organic Framework Gel.

Metal-organic framework (MOF) gel, an emerging subtype of MOF structure, is unique in formation and function; however, its evolutionary process remains elusive. Here, the evolution of a model gel-based MOF, UiO-66(Zr) gel, is explored by demonstrating its sequential sol-gel self-assembly and nonclassical gel-crystal transformation. The control of the sol-gel process enables the observation and characterization of structures in each assembly stage (phase-separation, polycondensation, and hindered-crystallization) and facilitates the preparation of hierarchical materials with giant mesopores.

Organolead Halide-Based Coordination Polymers: Intrinsic Stability and Photophysical Applications.

ConspectusOrganolead halide-based photovoltaics are one of the state-of-the-art solar cell systems with efficiencies increasing to 25% over the past decade, ascribed to their high light-absorption coefficient, broad wavelength coverage, tunable band structure, and excellent carrier mobility. Indeed, these optical characteristics are highly demanding in photocatalysis and photoluminescence (PL), which also involve the solar energy utilization and charge transport. However, the vast majority of organolead halides are ionically bonded structures and susceptible to degradation upon high-polarity protic molecules (e.

Bromo- and iodo-bridged building units in metal-organic frameworks for enhanced carrier transport and CO photoreduction by water vapor.

Organolead halide hybrids have many promising attributes for photocatalysis, e.g. tunable bandgaps and excellent carrier transport, but their instability constraints render them vulnerable to polar molecules and limit their photocatalysis in moisture.

Efficient and reusable catalysis of benzylic C-H oxidation over layered [Co(OH)] derivatives.

Aerobic oxidation of benzylic C(sp)-H bonds in a green and heterogeneous manner is a major target in organic catalysis. Herein, we report the synthesis of 3D coordination polymers containing [Co(OH)] layers, affording reusable and efficient oxidation of ethylbenezene and tetralin by using O as the oxidant. Moreover, the cleavage of Co-carboxylate bonding renders atomically thin cobaltate nanosheets and enhanced catalytic performance.

Fabrication of Robust and Porous Lead Chloride-Based Metal-Organic Frameworks toward a Selective and Sensitive Smart NH Sensor.

Organolead halide materials have shown promising optoelectronic properties that are suitable for light-emitting diodes (e.g., strong photoluminescence, narrow emission width, and high charge carrier mobility).

Precise incorporation of transition metals into organolead oxyhalide crystalline materials for photocatalysis.

Organolead halide crystalline materials are an emerging class of high-performance photocatalysts. However, limited studies have been performed to tune their photoactive properties by precise introduction of transition metals. Herein, we report the successful incorporation of four different transition metal centers (Mn, Co, Ni and Zn) into a lead oxyhalide crystalline matrix via isoreticular synthesis.

N-Heterocyclic Carbene-Stabilized Ultrasmall Gold Nanoclusters in a Metal-Organic Framework for Photocatalytic CO Reduction.

Ultrafine gold nanoclusters (Au-NCs) are susceptible to migrate and aggregate, even in the porosity of many crystalline solids. N-heterocyclic carbenes (NHCs) are a class of structurally diverse ligands for the stabilization of Au-NCs in homogeneous chemistry, showing catalytic reactivity in CO activation. Herein, for the first time, we demonstrate a heterogeneous nucleation approach to stabilize ultrasmall and highly dispersed gold nanoclusters in an NHC-functionalized porous matrix.

Intrinsic self-trapped broadband emission from zinc halide-based metal-organic frameworks.

Organolead halide perovskites are an emerging class of intrinsic self-trapped broadband emitters, but suffer from lead toxicity and stability problems. Herein, we report a series of metal-organic frameworks (MOFs) based on 0-D zinc halide secondary building units (SBUs), which emit large Stokes shifted broadband bluish-white light. A variety of photophysics studies demonstrate that the broadband emission probably originates from self-trapped excitons, owing to the structurally deformable SBUs.

Efficient, broadband self-trapped white-light emission from haloplumbate-based metal-organic frameworks.

Metal-organic frameworks (MOFs) with low-dimensional, deformable haloplumbate secondary building units (SBUs) are an emerging class of intrinsic white-light emitters combining advantageous properties of both MOFs and lead perovskites. Herein, we have successfully synthesized two MOFs with haloplumbate SBUs occupying an extremely high degree of structural strain with local zigzag Pb-X-Pb-X (X = Cl/Br) connectivity located in single-stranded helices. Thus, the electron-phonon coupling in the deformable SBUs affords intrinsic white-light emission and moderately high external photoluminescence quantum efficiencies of 12-15%, superior to our previously reported MOFs.

N-heterocyclic carbene-functionalized metal-organic frameworks for the chemical fixation of CO.

N-heterocyclic carbenes (NHCs) are a class of molecules with a lone pair of carbene electrons and thus, they have the ability to activate CO2 to form imidazolium carboxylates. The incorporation of activated, metal-free NHC moieties into metal-organic frameworks (MOFs) without the decomposition of metal-carboxylate coordination motifs is highly desired owing to the high CO2 affinity and versatile chemical functionalities in MOFs. Herein, we have summarized the recent in situ generation approaches to form metal-free NHC-functionalized MOFs, which are a unique class of CO2-conversion catalysts with high catalytic activity, selectivity and stability, superior to those of homogenous and other heterogeneous NHC analogues.

A moisture-stable organosulfonate-based metal-organic framework with intrinsic self-trapped white-light emission.

Weakly-coordinating organosulfonate linkers are significantly less studied in MOFs, but promising in terms of enhancing the structural strain of SBUs owing to their versatile coordination towards metals. Herein, we have successfully synthesized a porous, moisture-resistant organosulfonate-based MOF with structurally deformable 1D zigzag [CdCl] chains. The material is one rare MOF exhibiting intrinsic broadband white-light emission with an external quantum efficiency exceeding 10%, probably owing to the strong electron-phonon coupling in the orgnosulfonate-bridged deformable inorganic units.

Synthesis and Applications of Porous Organosulfonate-Based Metal-Organic Frameworks.

Metal-organic frameworks (MOFs) are an emerging class of porous crystalline materials attracting attention for their vast array of topologies as well as potential applications in gas storage, heterogeneous catalysis, and molecular sensing. In most cases, organocarboxylates (or corresponding carboxylic acids) are the most common building block, achieving well-defined metal-carboxylate coordination motifs in MOF structures. However, organosulfonates (or corresponding sulfonic acids) have been less well studied in MOF chemistry, probably owing to the weak coordination tendency of the sulfonate oxygens toward metal centers.

UiO-type metal-organic frameworks with NHC or metal-NHC functionalities for N-methylation using CO as the carbon source.

We demonstrate the first metal-organic framework (MOF) that catalyzes N-methylation of amines using 1 atm CO2 and phenylsilane under ambient conditions. Compared with its homogeneous analog, the incorporation of N-heterocyclic carbene (NHC) into the MOF provides more efficient catalysis with improved reaction kinetics, turnover numbers and recyclability. Moreover, the metalated NHC functionalized MOF achieves direct N-methylation of amines bearing carboxylate moieties, which are common building blocks in pharmaceutical chemistry.

Intrinsic White-Light-Emitting Metal-Organic Frameworks with Structurally Deformable Secondary Building Units.

The secondary building units in metal-organic frameworks (MOFs) are commonly well-defined metal-oxo clusters or chains with very limited structural strain. Herein, the structurally deformable haloplumbate units that are often observed in organolead halide perovskites have been successfully incorporated into MOFs. The resultant materials are a rare class of isoreticular MOFs exhibiting large Stokes-shifted broadband white-light emission, which is probably induced by self-trapped excitons from electron-phonon coupling in the deformable, zigzag [Pb X ] (X=Cl, Br, or I) chains.

In Situ Generation of an N-Heterocyclic Carbene Functionalized Metal-Organic Framework by Postsynthetic Ligand Exchange: Efficient and Selective Hydrosilylation of CO.

The reported metal-organic framework (MOF) catalyst realizes CO to methanol transformation under ambient conditions. The MOF is one rare example containing metal-free N-heterocyclic carbene (NHC) moieties, which are installed using an in situ generation strategy involving the incorporation of an imidazolium bromide based linker into the MOF by postsynthetic ligand exchange. Importantly, the resultant NHC-functionalized MOF is the first catalyst capable of performing quantitative hydrogen transfer from silanes to CO , thus achieving quantitative (>99 %) methanol yield.