Structural Variants and Ultralow Detection Ability for Tryptamine in Two Polymorphs of a Zincophosphite Framework

Two organic-inorganic hybrid zinc phosphites incorporating 1,2,4,5-tetrakis(imidazol-1-ylmethyl)benzene (TIMB) molecules were synthesized under hydro(solvo)thermal methods and structurally characterized by single-crystal X-ray diffraction (SCXD). Interestingly, the solvent ratio of water to dimethylformamide induced the formation of a new compound of Zn2(TIMB)0.5(HPO3)2·3H2O (1) and our previously reported structure of Zn2(TIMB)0.5(HPO3)2·H2O (2). Additionally, their dehydrated crystals (1a and 2a) were prepared through heat treatment at 150 °C. SCXD and powder X-ray diffraction showed that all four compounds share the same framework formula of Zn2(TIMB)0.5(HPO3)2 but exhibit a huge difference in their inorganic components and final structures. In 1 and 1a, the inorganic units formed two-dimensional zincophosphite layers, while in 2 and 2a, they formed one-dimensional chains. The inorganic parts of 1 (1a) and 2 (2a) were bridged with TIMB linkers, resulting in 3D structures with rectangular and tubular windows, respectively. Furthermore, 1 was coated on the screen-printed carbon electron as a hybrid material, displaying excellent performance while having a linear relationship with an R2 value of 0.99 within the concentration range of 10-10 to 10-6 mol/L for detecting tryptamine (Try) molecules. Moreover, the results showed that 1 exhibits an ultralow limit of detection of 5.43 × 10-11 mol/L and high specificity toward Try over histamine, ascorbic acid, uric acid, and glucose. The synthesis, structural diversity, stability, and sensing ability are also discussed.

From Centrosymmetry to Noncentrosymmetry: Precise Structural Regulation and Characterization on ZnHPO3·2H2O Polymorphs

Polymorphs of ZnHPO₃·2H₂O with centrosymmetry (Cmcm) and noncentrosymmetry (C2) structures were prepared by modified solution evaporation and seed-crystal-induced secondary nucleation methods. In Cmcm-ZnHPO₃·2H₂O, the zinc atoms are only octahedrally coordinated, while in C2-ZnHPO₃·2H₂O, they feature both tetrahedral and octahedral coordination. As a result, Cmcm-ZnHPO₃·2H₂O features a 2D layered structure with lattice water molecules located in the interlayer space, while C2-ZnHPO₃·2H₂O features a 3D electroneutral framework of tfa topology connected by Zn(1)O₄, Zn(2)O₆, and HPO₃ units. The UV-visible diffuse reflectance spectra associated with Tauc's analyses give a direct bandgap of 4.24 and 4.33 eV for Cmcm-ZnHPO₃·2H₂O and C2-ZnHPO₃·2H₂O, respectively. Moreover, C2-ZnHPO₃·2H₂O exhibits a weak second harmonic generation (SHG) response and a moderate birefringence for phase matching, indicating its potential as a nonlinear optical material. Detailed dipole moment calculation and analysis confirmed that the SHG response mainly derived from the HPO₃ pseudo-tetrahedra.

Uncommon 3D Twofold Interpenetrated Zinc Phosphate Consisting of Inorganic Chains and Mixed Ligands for Highly Efficient Dye Removal Ability Using Its Nanosized Particles

The flexible blocks are the primary building units for constructing crystalline solids with interpenetrating structures. Herein, we reported a novel class of crystalline material with such structural features, which was made of two tetradentate ligands and one-dimensional (1D) rigid chains of zinc phosphate. This is also the first example of transition metal phosphate incorporating a squarate linker. Furthermore, efficient dye removal ability has been presented.

Stable Crystalline Organic-Inorganic Hybrid Indium Phosphate with Dye Removal and Ractopamine Detection Applications

A highly stable framework of an organic-inorganic hybrid indium phosphate (NTOU-7) was synthesized under hydro(solvo)thermal conditions and structurally characterized by single-crystal X-ray diffraction and solid-state NMR spectroscopy. This is the first example of a post-transition-metal phosphate incorporating tetradentate organic molecules. The In atoms in the inorganic layers are coordinated by imidazole rings of the 1,2,4,5-tetrakis(imidazol-1-ylmethyl)benzene linkers to generate a new solid-state material. NTOU-7 showed high chemical stability and displayed excellent performance for both dye removal and ractopamine (RAC) detection, which are interesting environmental and biosensing applications. The sensitivity and ultralow limit of detection were 607.9 μA·μM·cm^-2 and 2.74 × 10^-10 mol·L^-1 (0.08 ppb), which meet the requirements stated by the Codex Alimentarius Commission (10 ppb RAC residue in beef and pork). The detection performance was confirmed by sensing spiked-in RAC in real pork samples. We also reported the synthesis, characterization, structural stability, dye removal, and sensing properties of NTOU-7.

Molecular pathogenesis of pediatric thyroid carcinoma

There has been little understanding of the molecular pathogenesis of pediatric thyroid cancers. Most of them are histologically classified as papillary thyroid carcinoma (PTC). Ionizing radiation is the most important environmental factor to induce PTC, especially in children. Particularly, radiation-related pediatric PTCs after the Chernobyl accident provided invaluable information. In addition, the recent accumulation of sporadic pediatric PTC cases, partly due to advances in diagnostic imaging, has also provided insight into their general pathogenesis. In PTC development, basically two types of genetic alterations, fusion oncogenes, mainly RET/PTC, and a point mutation, mainly BRAFV600E, are thought to play a key role as driver oncogenes. Their frequencies vary depending on patient age. The younger the age, the more prevalent the fusion oncogenes are. Higher incidence of fusion oncogenes was also observed in cases exposed to radiation. In short, fusion oncogenes are associated with both age and radiation and are not evidence of radiation exposure. The type of driver oncogene is shifted toward BRAFV600E during adolescence in sporadic PTCs. However, until about this age, fusion oncogenes seem to still confer dominant growth advantages, which may lead to the higher discovery rate of the fusion oncogenes. It has been postulated that RET/PTC in radiation-induced PTC is generated by ionizing radiation; however, there is an interesting hypothesis that thyroid follicular cell clones with pre-existing RET/PTC were already present, and radiation may play a role as a promoter/progressor but not initiator. Telomerase reverse transcriptase gene (TERT) promoter mutations, which are the strongest marker of tumor aggressiveness in adult PTC cases, have not been detected in pediatric cases; however, TERT expression without the mutations may play a role in tumor aggressiveness. In this paper, the recent information regarding molecular findings in sporadic and radiation-associated pediatric PTCs is summarized.

Studies on the Genesis and Proton Conductivity of Imidazole-Based Linear and Open-Framework Zinc Phosphites

Three new zinc phosphites, [HIm]₂[Zn₃(HPO₃)₄] (1), [Zn₂(HPO₃)₂Im₂] (2), and [Zn(HPO₃)Im] (3) (Im = imidazole), have been synthesized from the hydro/solvothermal reaction of zinc acetate, dimethyl phosphite, and imidazole by varying the temperature and solvent of the reaction medium. The structure of 1 is built from vertex-sharing of four HPO₃-capped Zn₃P₃ units and adopts an open framework with 12-ring channels stabilized by HIm cations via N-H···O hydrogen bonds. For 2, the inorganic skeleton is comprised of alternating ZnO₄ and HPO₃ tetrahedra, while the coordinatively associated ZnN₂O₂ fragments occupy the 12-ring hexagonal channels. Compound 3 adopts a ladder-type one-dimensional structure and exhibits N-H···O hydrogen-bonding interactions to afford a supramolecular assembly. A plausible rationale on the genesis of 1-3 has been put forth by reacting the preformed inorganic zinc phosphites Zn{OP(O)(OMe)H}₂ or [Zn₂(HPO₃)₂(H₂O)₄]·H₂O with imidazole as the structure-directing ligand. Alternating-current impedance measurements reveal that 1 and 3 exhibit proton conductivities on the order of 10^-3-10^-4 S cm^-1 between 25 and 100 °C under 35 and 77% relative humidity in repeated impedance cycles (E_a = 0.22-0.35 eV). On the contrary, the conduction property is completely impaired in 2 under similar conditions.

Amino acid-templated zinc phosphites: low-dimensional structures, fluorescence, and nonlinear optical properties

Two new zinc phosphites were prepared using the amino acid alanine as a structure-directing agent. They have tubular and ladder-like structures, exhibiting blue fluorescence upon UV light irradiation. Notably, the tubular structure is unprecedented in metal phosphite systems. The compound is a nonlinear optically active solid with a second-harmonic generation efficiency of about 1.2 times that of KH2PO4 (KDP).

Recent developments in organic-inorganic hybrid metal phosphates and phosphites

The design and synthesis of crystalline materials have been a subject of intensive research because of their interesting structures, physicochemical properties, and potential applications. However, the crystalline structure of organic-inorganic hybrid materials collapses to lose the structural features of the original networks and/or frameworks when exposed to different stimuli such as pH, vapor, water, high temperature, and organic solvents. This hampers further studies focusing on practical applications. Although several review articles provide reasonable pathways for the preparation of stable metal-organic frameworks (MOFs) and coordination polymers (CPs), the synthesis and design of stable materials containing organic species remain challenging. In this frontier article, we discuss the development of crystalline MOF, CP, metallophosphate, and metallophosphite materials, and provide a feasible approach for the formation of stable organic-inorganic hybrid compounds that combine MOFs (or CPs) and phosphate (or phosphite) building elements. In addition to their interesting structures, the synthetic strategies and structural stabilities of such hybrid composites are also presented.

Pillared-layered indium phosphites templated by amino acids: isoreticular structures, water stability, and fluorescence

Two crystalline open-framework indium phosphites (denoted SCU-31 and SCU-32) were prepared using amino acids as structure-directing agents. They have isoreticular pillared-layered structures built up from 6 × 1 and 4 = 1 clusters. Notably, the two compounds show excellent water stability and exhibit blue fluorescence under UV light irradiation at room temperature. The proton-conducting behaviour of SCU-31 was also investigated.

Designable Aluminum Molecular Rings: Ring Expansion and Ligand Functionalization

Presented herein are the Al^III molecular ring architectures from 8-ring to 16-ring. Although there are numerous reported cyclic coordination compounds based on transition metals, gallium, or lanthanides, the Al versions are less developed due to the fast hydrolysis nature of Al³⁺ ion. With the assistant of monohydric alcohols, a series of atomic precisely Al molecular rings based on benzoates are synthesized. The ring expansion of these Al-rings from 8-ring to 16-ring is related to the monohydric alcohol structure-directing agents. Moreover, the organic ligands on the Al-rings can be modified by using various benzoate derivatives, which lead to tunable surface properties of the Al-rings from hydrophilicity to ultra-hydrophobicity. Importantly, 4-aminobenzoic acid bridged 16-ring is soluble in organic solvents and exhibits high solution stability revealed by mass spectroscopy. Ligand substitution also can be performed between these Al-rings, which reveal controllable ligand functionalization of these Al-rings.

The Different Effects of Organic Amines on Synthetic Metal Phosphites/Phosphates

Four metal phosphites/phosphates crystal materials C₈N₄H₃₄Al₂P₄O₁₈ (1), C₃N₂H₁₇GaP₂O₈ (2), H₅In₂P₃O₁₀ (3), and H₉In₂P₃O₁₃ (4) have been solvothermally synthesized by organic amines in the presence of mixed solvents. Structural analyses indicate that compound 1 and 2 show one-dimensional (1D) chain structures; compound 3 and 4 are three-dimensional (3D) inorganic open-framework indium phosphites. Organic amines show different mechanisms in the four compounds. The 2,2′-bipyridine organic amine acts as a template source and it breaks down small molecules, which enter into the structure of compound 1. For compound 2, 1,2-propanediamine has a role as protonated template and it forms a hydrogen bond with the inorganic skeleton structure. As for compound 3 and 4 without the organic template, the benzylamine and 2,2′-bipyridine mainly serve as structure-directing agent. Especially, compound 3 has an odd seven-ring channel, and compound 4 contains 3D intersecting six-ring, eight-ring, and 10-ring channels. X-ray diffraction (XRD), scanning electron microscopy (SEM), CHN, inductive coupled plasma (ICP), Infrared (IR), and thermal gravimetric (TG) analyze the four compounds.

A thio-functionalized zinc phosphite with a large-channel framework and enhanced removal ability of mercury ion from aqueous solutions

New thio-functionalized zinc phosphite (NTOU-2S) exhibited the different structural properties and removal ability of Hg²⁺ cation from the sulfur-free NTOU-2.

Ionothermal synthesis of crystalline metal phosphites using multifunctional protic ionic liquids

A mixed-valence iron phosphite was prepared under ionothermal conditions using a protic ionic liquid as a solvent, a structure-directing agent, a phosphorus source, and a reducing agent.

Coordinate bond- and hydrogen bond-assisted electron transfer strategy towards the generation of photochromic metal phosphites

The introduction of conjugated dipyridine-derivative units into metal phosphite system produces two hybrid zincophosphites driven by the coordinate bond- and hydrogen bond-assisted electron transfer.

A new cluster-based chalcogenide zeolite analogue with a large inter-cluster bridging angle

A new cluster-based chalcogenide zeolite analogue with a large inter-cluster bridging angle.

Ionothermal synthesis of a photoelectroactive titanophosphite with a three-dimensional open-framework

A new titanophosphite open-framework exhibits photovoltaic properties and photocatalytic activity as an n-type semiconductor.

Cluster–oxalate frameworks with extra-large channels: solvent-free synthesis, chemical stability, and proton conduction

Two cluster–oxalate frameworks (denoted as SCU-62 and SCU-65) were prepared under solvent-free conditions.

A dual fluorescent/phosphorescent zincophosphite with interesting water adsorption and structural transformation properties

This is a very rare example of a crystalline metallophosphite/phosphate framework with structural transformation, water adsorption, and luminescence color switching (blue to green).

Two- and three-dimensional hybrid zinc phosphites: syntheses, structures and photoluminescence properties

Two zinc-phosphites modified by a rigid amine 3,5-bis(imidazole-1-yl)pyridine (BIP), [Zn2(HPO3)2(BIP)]·H2O (1) and [Zn3(HPO3)3(BIP)(H2O)]·H2O (2), were solvothermally prepared. Compound 1 possesses a zincophosphite layer decorated by BIP moieties via coordinating to intralayer Zn(ii) ions. Compound 2 features a 3D frame with a pillar-layer structure, in which the organic BIP pillars the inorganic zincophosphite layer via coordinating to interlayer Zn(ii) ions. The structural diversity from a 2D layer to a 3D frame was mainly attributable to the different bridging modes of BIP in the process of assembly. Their temperature-dependent photoluminescence properties have also been studied.

Indium Phosphite-Based Porous Solids Exhibiting Organic Sensing and a Facile Route to Superhydrophobicity

In searching for practical crystalline porous solids, two unique hybrid materials with featured functions, In-bpy and In-dpe, were prepared without deliberately designed organic linker units or complex post-modification procedures. Composed of oxalate-embedded metal phosphite (MPO) sheets and bipyridyl-type ligands of varied molecular lengths, they show a common pillar-layered topology but are the first well-characterized organo-MPOs to possess genuine porosity, substantiated by CO₂ adsorption, and structural stability under harsh conditions. In-bpy exhibits a turn-on fluorescence signal when in contact with p-xylene, making it the first MPO-based sensing material with selectivity and recyclability. Furthermore, In-dpe demonstrates a facile and unprecedented route to the superhydrophobicity of porous solids via a [2+2] photocycloaddition reaction between linker and foreign units. Our findings suggest that MPO may serve as a promising platform for hybrid frameworks to create many more functional porous materials.

Bipyridine-triggered modulation of structure and properties of zinc-diphosphonates: coordination role vs. template rule

Two layered zinc-diphosphonates driven by 4,4′-bipy are prepared and their structural diversities are caused by the distinct roles of 4,4′-bipy in the process of assembly. The luminescence and proton conduction are studied.

Solvent-free synthesis and room temperature proton conductivity of new cobalt phosphite–oxalates

Two new cobalt phosphite–oxalates (1 and 2) have been synthesized under solvent-free conditions. Compound 2 possesses room temperature proton conductivity.

An organic–inorganic hybrid zinc phosphite framework with room temperature phosphorescence

An organic–inorganic hybrid zinc phosphite framework with large channels and fascinating room temperature phosphorescence has been presented.

Two New Copper Borates with Mesoscale Cubic Supramolecular Cages Assembled from {Cu4 @B20 } Clusters

Two new copper borates, namely H₆ [(μ₄ -O)Cu₄ @B₂₀ O₃₂ (OH)₈ ]⋅25 H₂ O (1) and H₆ [(μ₄ -O)Cu₄ @B₂₀ O₃₂ (OH)₈ ]⋅34 H₂ O⋅8 H₃ BO₃ (2), with 3D supramolecular framework have been made under solvothermal conditions, which built by novel cubic supramolecular cages with mesoscale cavities via the H-bondings. Interestingly, the cage is assembled by [(μ₄ -O)Cu₄ @B₂₀ O₃₂ (OH)₈ ] ({Cu₄ @B₂₀ }) cluster units with different point-group symmetry. Owing to extra H₃ BO₃ molecules participated in building the supramolecular framework, 2 has a larger cubic cage size and higher non-framework volume, leading to the cage size extended to mesoporous size set as a version of ''1 plus".

A highly flexible inorganic framework with amphiphilic amine assemblies as templates

A zinc phosphite-phosphate framework, (HA)₂[Zn₃(HPO₃)_4-x(HPO₄)_x] (1; A = cha, coa, iba, pa, and ha; x = 0.3-1) with nanometer-scale channels was prepared. The framework exhibited an extraordinarily high flexibility, 13% expansion at ambient pressure and 27% contraction under a high pressure of over 2.3 GPa without undergoing any phase transformation. The volume changes in the compression-decompression process are reversible. Such unusual adaptability is rare in pure inorganic networks. The molecular volumes of templates range from 165 ų to 228 ų, which allows to vary channel aperture increasingly from 13.02 to 15.34 Å. Remarkably, three types of organic amine template assemblies, captured in inorganic frameworks, were identified in this study. Presented herein is the first example that demonstrates a successfully controlled template assembly that helps to obtain a flexible inorganic framework with nanosized pores in a systematic manner.

Two hybrid transition metal triphosphonates decorated with a tripodal imidazole ligand: synthesis, structures and properties

Two transition-metal triphosphonates with pillar-layered structures were synthesized and characterized. The luminescence, magnetic and proton conductive properties were investigated.

A series of color-tunable light-emitting open-framework lanthanide sulfates containing extra-large 36-membered ring channels

A series of lanthanide sulfates contain 36-ring channels with the pore size (22.0 × 16.8 Å) based on Eu₁₀clusters.

Syntheses and Characterizations of Three Organically Templated Zinc Phosphites with 12-Ring Channels

Three new zinc phosphites, [Hapy]2[Zn3(HPO3)4] (1; apy = 4-aminopyridine), [H2hepip][Zn3(HPO3)4]·(H2O)0.25 (2; hepip = N-(2-hydroxyethyl)piperazine), and [H2tmdab][Zn3(HPO3)4] (3; tmdab = N,N,N′,N′-tetramethyl-1,3-diaminobutane), have been synthesized and characterized by infrared spectroscopy, elemental analysis, thermogravimetric analysis, and powder and single-crystal X-ray diffraction. The frameworks of 1–3 are constructed from 4-connected ZnO4 tetrahedra and 3-connected HPO3 pseudo pyramids with distinct connection mode driven by different organic amine templates. There are 12-membered ring (12-MR) and 8-MR apertures in the (3,4)-connected three-dimensional architecture of 1–3. It is notable that helical chains are observed in the framework of compound 3.