Giant Birefringence Induced by Intermolecular Aromatic Interactions in Hydrogen-Bonded Organic Frameworks.

Birefringent crystals are crucial optical materials that play a pivotal role in modulating and detecting the polarization state of light. However, there is still a significant challenge in regulating the assembly of π-conjugated active units to construct optical crystals with giant birefringence. In this study, a hydrogen-bonding self-assembly strategy is proposed to construct an aromatic π-conjugated hydrogen-bonded organic framework birefringent crystal (HOFBC) which exhibits a remarkable birefringence value of 0.

Regulating electron transfer and orbital interaction within metalloporphyrin-MOFs for highly sensitive NO sensing.

The understanding of electron transfer pathways and orbital interactions between analytes and adsorption sites in gas-sensitive studies, especially at the atomic level, is currently limited. Herein, we have designed eight isoreticular catechol-metalloporphyrin scaffolds, FeTCP-M and InTCP-M (TCP = 5,10,15,20-tetrakis-catechol-porphyrin, M = Fe, Co, Ni and Zn) with adjustable charge transfer schemes in the coordination microenvironment and precise tuning of orbital interactions between analytes and adsorption sites, which can be used as models for exploring the influence of these factors on gas sensing. Our experimental findings indicate that the sensitivity and selectivity can be modulated using the type of metals in the metal-catechol chains (which regulate the electron transfer routes) and the metalloporphyrin rings (which fine-tune the orbital interactions between analytes and adsorption sites).

Multilevel-Regulated Metal-Organic Framework Platform Integrating Pore Space Partition and Open-Metal Sites for Enhanced CO Photoreduction to CO with Nearly 100% Selectivity.

Rational design and regulation of atomically precise photocatalysts are essential for constructing efficient photocatalytic systems tunable at both the atomic and molecular levels. Herein, we propose a platform-based strategy capable of integrating both pore space partition (PSP) and open-metal sites (OMSs) as foundational features for constructing high-performance photocatalysts. We demonstrate the first structural prototype obtained from this strategy: pore-partitioned NiTCPE- (TCPE = 1,1,2,2-tetra(4-carboxylphenyl)ethylene, = partitioned topology).

Bio-Inspired Synthetic Hydrogen-Bonded Organic Frameworks for Efficient Proton Conduction.

Hydrogen-bonded organic frameworks (HOFs) are a rising class of promising proton-conducting materials. However, they always suffer from the inherent contradiction between chemical stability and proton conduction. Herein, inspired by the self-assembly of lipid bilayer membranes, a series of aminomethylphosphonic acid-derived single-component HOFs are successfully developed with different substituents attached to the phosphonate oxygen group.

Facile Synthesis of a Long Afterglow Calcium-Organic Framework in Water.

Presented here is a water-stable Ca-MOF that has been facilely synthesized from the metastable 3D framework in water and exhibits room-temperature phosphorescence with second scale long afterglow.

Black Titanium-Oxo Clusters with Ultralow Band Gaps and Enhanced Nonlinear Optical Performance.

A series of catecholate-functionalized titanium-oxo clusters (TOCs), to , with atomically precise structures were synthesized and characterized, including distinctive "boat" and "chair" conformations in and , respectively. These cluster compounds are prominent for their ultralow optical band gaps, as is visually evident from the rather unusual black TOCs (B-TOCs), to . The cluster structures were found to be ultrastable with respect to air, water, organic solvents, and even acidic or basic aqueous solutions in a wide pH range (pH 0-13), owing to the stabilizing effects of catecholate and its derivatives, as well as the carboxylate ligands.

Energy Band Alignment and Redox-Active Sites in Metalloporphyrin-Spaced Metal-Catechol Frameworks for Enhanced CO Photoreduction.

Two new chemically stable metalloporphyrin-bridged metal-catechol frameworks, InTCP-Co and FeTCP-Co, were constructed to achieve artificial photosynthesis without additional sacrificial agents and photosensitizers. The CO photoreduction rate over FeTCP-Co considerably exceeds that obtained over InTCP-Co, and the incorporation of uncoordinated hydroxyl groups, associated with catechol, into the network further promotes the photocatalytic activity. The iron-oxo coordination chain assists energy band alignment and provides a redox-active site, and the uncoordinated hydroxyl group contributes to the visible-light absorptance, charge-carrier transfer, and CO -scaffold affinity.

Two Isostructural Titanium Metal-Organic Frameworks for Light Hydrocarbon Separation.

Presented here is the light hydrocarbon separation of titanium metal-organic frameworks (Ti-MOFs). Compared with the cyclic Ti-oxo cluster (TiO(CO), ), porous structures of and (FIR = Fujian Institute Research) can effectively improve the adsorption amounts of light hydrocarbons. The introduction of different functional groups and Ti-oxo clusters with small window sizes enables them to exhibit the highly selective separation of C and C hydrocarbons versus methane in an ambient atmosphere.

Designable Assembly of Aluminum Molecular Rings for Sequential Confinement of Iodine Molecules.

Although numerous adsorbent materials have been reported for the capture of radioactive iodine, there is still demand for new absorbents that are economically viable and can be prepared by reliable synthetic protocols. Herein, we report a coordination-driven self-assembly strategy towards adsorbents for the sequential confinement of iodine molecules. These adsorbents are versatile heterometallic frameworks constructed from aluminum molecular rings of varying size, flexible copper ions, and conjugated carboxylate ligands.

Mesoporous Assembly of Aluminum Molecular Rings for Iodine Capture.

The effective capture and storage of radioiodine are of worldwide interest for sustainable nuclear energy. However, the direct observation of ambiguous binding sites that accommodate iodine is extremely rare. We presented herein a crystallographic visualization of the binding of iodine within mesoporous cages assembled from aluminum molecular rings.

Understanding the Efficiency and Selectivity of Two-Electron Production of Metalloporphyrin-Embedded Zirconium-Pyrogallol Scaffolds in Electrochemical CO Reduction.

Because of the high efficiency and mild reaction conditions, electrocatalytic CO reduction (ECR) has attracted significant attention in recent years. However, the specific mechanism of the formation of the two-electron production (CO or HCOOH) in this reaction is still unclear. Herein, with density functional theory calculation and experimental manipulation, the specific mechanism of the selective two-electron reduction of CO has been systematically investigated, employing the polyphenolate-substituted metalloporphyrinic frameworks, ZrPP-1-M (M = Fe, Co, Ni, Cu, and Zn), as model catalysts.

Tetrahedral Geometry Induction of Stable Ag-Ti Nanoclusters by Flexible Trifurcate TiL Metalloligand.

A series of increasingly large silver nanoclusters with a varied combination of Archimedean and/or Platonic solid arrangements was constructed using a flexible trifurcate TiL (L = Salicylic acid or 5-fluorosalicylic acid) metalloligand: Ag@Ag@Ti (), Ag@Ti (), Ag@Ag@Ag@Ti (), Ag@Ag@Ag@Ti (), and Ag@Ag@Ti (). The silver nanoclusters are each capped by four TiL moieties, thereby forming {Ti} supertetrahedra with average edge lengths ranging from ∼8.12 Å to ∼17.

Adjustment of the performance and stability of isostructural zeolitic tetrazolate-imidazolate frameworks.

Presented here are two isostructural SOD-type zeolitic tetrazolate-imidazolate frameworks (ZTIFs), Zn(etz)0.86(mim)1.14 (ZTIF-9, Hetz = 5-ethyltetrazole, Hmim = 2-methylimidazole) and Zn(vtz)0.

Two new inorganic-organic hybrid zinc phosphites and their derived ZnO/ZnS heterostructure for efficient photocatalytic hydrogen production.

Two novel inorganic-organic hybrid zinc phosphites, namely, [Zn(1,2-bimb)(HPO)] (1) and [Zn(1,4-bmimb)(HPO)] (2), (1,2-bimb = 1,2-bis(imidazol-1ylmethyl)benzene; 1,4-bmimb = 1,4-bis((2-methyl-1-imidazol-1yl)methyl)benzene) were synthesized for the first time by hydrothermal reaction. Compound 1 generates a three-dimensional (3D) pillared-layer structure with a 2-nodal 3,4-connected topology. While compound 2 exhibits a 2D hybrid zinc phosphite sheet with a 3,4-connected topology network.

Synthesis of Anionic Metal-Organic Zeolites for Selective Gas Adsorption and Ion Exchange.

We report here a new method to construct metal-organic zeolites (MOZs) via the mixing of dicarboxylic acid and tetrazole ligands. Two anionic MOZs, MOZ-200 and MOZ-201 with BCT and ATN topologies, were developed successfully by this approach and exhibit high selective CO uptake and Ln ion exchange.

Acid and Base Resistant Zirconium Polyphenolate-Metalloporphyrin Scaffolds for Efficient CO Photoreduction.

A series of zirconium polyphenolate-decorated-(metallo)porphyrin metal-organic frameworks (MOFs), ZrPP-n (n = 1, 2), featuring infinite Zr -oxo chains linked via polyphenolate groups on four peripheries of eclipse-arranged porphyrin macrocycles, are successfully constructed through a top-down process from simulation to synthesis. These are the unusual examples of Zr-MOFs (or MOFs in general) based on phenolic porphyrins, instead of commonly known carboxylate-based types. Representative ZrPP-1 not only exhibits strong acid resistance (pH = 1, HCl) but also remains intact even when immersed in saturated NaOH solution (≈20 m), an exceptionally large range of pH resistance among MOFs.