New Zinc Phosphates Decorated by Imidazole-Containing Ligands

Two histidine-templated metal phosphate-oxalates: solvent-free synthesis, luminescence, and proton-conducting properties

Two new histidine-templated metal phosphate-oxalates (MPOs) were prepared under solvent-free conditions. Single-crystal X-ray diffraction analysis reveals that they have layered and chainlike structures, respectively. Under ultraviolet light irradiation, the two MPOs exhibit blue luminescence originating from histidine templates. Their proton-conducting properties were also investigated under different conditions.

Two amino acid-templated metal phosphates: surfactant-thermal synthesis, water stability, and proton conduction

Two new metal phosphates, namely, Zn(HPO₄)(C₆H₁₁NO₂) (1) and (C₅H₁₀NO₂)Ga₄(PO₄)₄F·3H₂O (2), were prepared under surfactant-thermal conditions. Single-crystal X-ray diffraction analyses reveal that compound 1 has a zigzag-chain structure decorated with homoproline and compound 2 has a three-dimensional zeolite-like structure templated by proline. Notably, compound 2 remains stable in both boiling water and aqueous solutions with a pH range of 2-12. It shows a proton conductivity of 8.89 × 10^-4 S cm^-1 at 85 °C and 95% relative humidity.

High proton conductivity behavior in a 2D metal sulfite constructed from a histidine ligand

In the presence of the amino acid histidine, an inorganic–organic hybrid metal sulfite, Zn₂(SO₃)₂(C₆N₃O₂H₉)₂·H₂O (1), has been prepared under hydrothermal conditions. Single-crystal X-ray diffraction analysis reveals that 1 shows a 2D layer framework built up from a classical second building unit (S4R), and bridged histidine molecule. Notably, it is the first report of a metal sulfite in the presence of an amino acid molecule. A 1D H-bonding array can be constructed by the H-bonding interaction between histidine molecules and sulfite groups. Moreover, a new function of metal sulfite for proton conduction was investigated by alternating-current impedance analysis. The results demonstrate that compound 1 shows a high proton conductivity of approximately 10⁻³ S cm⁻¹ at 348 K and 98% relative humidity.

In the presence of the amino acid histidine, an inorganic–organic hybrid metal sulfite (compound 1), has been prepared under hydrothermal conditions. Compound 1 shows a high proton conductivity of, approximately 10⁻³ S cm⁻¹ at 348 K and 98% RH.

Exploration of new water stable proton-conducting materials in an amino acid-templated metal phosphate system

Presented here is the first example of an amino acid-templated metal phosphate with a three-dimensional structure, which shows excellent water stability and a high proton conductivity at room temperature under 98% relative humidity.

Three iodocuprate hybrids symmetrically modulated by positional isomers and the chiral conformation of N-benzyl-methylpyridinium

The successful synthesis and structural analysis of three novel iodocuprate frameworks, [N-Bz-2-MePy]₂[Cu₅I₇] (1), [N-Bz-3-MePy]₂[Cu₅I₇] (2), and [N-Bz-4-MePy][Cu₄I₅] (3), exhibit an excellent structural directing effect of the conformationally chiral N-Bz-MePy⁺.

Coordination polymers built from 1,4-bis(imidazol-1-ylmethyl)benzene: from crystalline to amorphous

A review of the different crystalline and amorphous coordination polymers (CPs) built from 1,4-bis(imidazol-1-ylmethyl)benzene (bix) is presented, with special emphasis on the large variety of structures reported so far and their potential applications.

Crystal structure of a new homochiral one-dimensional zincophosphate containing l-me-thio-nine

catena-Poly[[(l-me-thio-nine-κO)zinc]-μ3-(hydrogen phosphato)-κ(3) O:O':O''], [Zn{PO3(OH)}(C5H11NO2S)] n , a new one-dimensional homochiral zincophos-phate, was hydro-thermally synthesized using l-me-thio-nine as a structure-directing agent. The compound consists of a network of ZnO4 and (HO)PO3 tetra-hedra that form ladder-like chains of edge-fused Zn2P2O4 rings propagating parallel to [100]. The chains are decorated on each side by zwitterionic l-me-thio-nine ligands, which inter-act with the inorganic framework via Zn-O coordination bonds. The structure displays inter-chain N-H⋯O and O-H⋯S hydrogen bonds.

Synthesis, Crystal Structures and Properties of Two-dimensional Complexes Constructed by Dicarboxylate and Bis(Imidazole) Co-ligands

The complexes {[Zn(1,3-bip)(3,5-pdc)]·2H2O}n and {[Cu(1,3-bip)(1,3-bdc)]·H2O}n, [1,3-bip=1,3-bis(imidazole)propane, 3,5-pdc=pyridine-3,5-dicarboxylic acid, 1,3-bdc=isophthalic acid], have been synthesised under hydrothermal conditions and structurally characterised. Their thermogravimetric and photoluminescence properties were also investigated.

A series of divalent metal coordination polymers based on isomeric tetracarboxylic acids: synthesis, structures and magnetic properties

A series of M(ii) coordination polymers has been synthesized. 1–3 contain 1D infinite chains, and these 1D chains are further linked by hydrogen bonding to form 3D supramolecular networks. While 4 and 5 show tetra- or penta-nodal 3D network, respectively.

Guest-adaptable and water-stable peptide-based porous materials by imidazolate side chain control

The peptide-based porous 3D framework, ZnCar, has been synthesized from Zn²⁺ and the natural dipeptide carnosine (β-alanyl-L-histidine). Unlike previous extended peptide networks, the imidazole side chain of the histidine residue is deprotonated to afford Zn–imidazolate chains, with bonding similar to the zeolitic imidazolate framework (ZIF) family of porous materials. ZnCar exhibits permanent microporosity with a surface area of 448 m² g⁻¹, and its pores are 1D channels with 5 Å openings and a characteristic chiral shape. This compound is chemically stable in organic solvents and water. Single-crystal X-ray diffraction (XRD) showed that the ZnCar framework adapts to MeOH and H₂O guests because of the torsional flexibility of the main His-β-Ala chain, while retaining the rigidity conferred by the Zn–imidazolate chains. The conformation adopted by carnosine is driven by the H bonds formed both to other dipeptides and to the guests, permitting the observed structural transformations.

Poly[[μ(2)-1,2-bis-(1H-imidazol-1-ylmeth-yl)benzene-κN:N](μ(2)-tereph-thalato-κO:O)zinc(II)]

In the title coordination polymer, [Zn(C(8)H(4)O(4))(C(14)H(14)N(4))](n), the Zn(II) atom is coordinated by two N atoms from two 1,2-bis-(imidazol-1-ylmeth-yl)benzene ligands as well as by the two O atoms from two terephthalate ligands, confering a tetra-hedral coordination geometry. The bridging ligands generate a three-dimensional structure.

Engineering homochiral metal-organic frameworks for heterogeneous asymmetric catalysis and enantioselective separation

Owing to the potential applications in technological areas such as gas storage, catalysis, separation, sensing and nonlinear optics, tremendous efforts have been devoted to the development of porous metal-organic frameworks (MOFs) over the past ten years. Homochiral porous MOFs are particularly attractive candidates as heterogeneous asymmetric catalysts and enantioselective adsorbents and separators for production of optically active organic compounds due to the lack of homochiral inorganic porous materials such as zeolites. In this review, we summarize the recent research progress in homochiral MOF materials, including their synthetic strategy, distinctive structural features and latest advances in asymmetric heterogeneous catalysis and enantioselective separation.