Hydrothermal synthesis,crystal structure and optical properties of a 2-D heterometallic iodoplumbate

A novel two-dimensional heterometallic iodoplumbate, [Pb₃I₁₀Cu₄(phen)₂]_n (phen = 1,10-phenanthroline) constructed from [Pb₃I₁₀]^4? iodoplumbate chains and [Cu₂I₄(phen)]^2? entities has been hydrothermally synthesized and structurally characterized. The solid compound exhibits an intriguing semiconducting property with E_g = 2.62 eV. The thermochromic behavior of the compound has been also studied.     

Synthesis,crystal structure and magnetic properties of a dinuclear dysprosium single-molecule magnet

To seek novel dysprosium based single-molecule magnets, a dinuclear dysprosium complex, namely [Dy₂(L)₂(DBM)₂(DMF)₂]·2DMF (1) was successfully obtained by employing tridentate Schiff base ligand (where H₂L = 2-hydroxy-N′’-(2-hydroxy-3-methoxybenzylidene) benzohydrazide), HDBM = dibenzoylmethane, DMF = dimethylformamide). Single-crystal X-ray structural analysis reveals that the key feature of 1 is neutral dinuclear complex, in which two Dy(III) ions with eight-coordinated environment are bridged by two phenoxido oxygen atoms from two Schiff base ligands. Interestingly, complex 1 could be regarded as the structurally related derivatives to our previous reported complex of [Dy₂(L)₂(DBM)₂(DMF)₂] (1a) but adding two guest DMF solvents. More importantly, the energy barrier to magnetic relaxation of 1 is slightly higher, with a value of 33 K, when compared to the corresponding complex 1a of 24 K, which provides a good example towards regulating magnetization dynamics in dinuclear dysprosium (III) single-molecule magnets by guest solvent molecules.     

Hydrothermal synthesis,crystal structure and spectroscopic properties of a novel 3D chromium(III) complex

The hydrothermal synthesis of CrCl₃·6H₂O, NaOH, 2,6-dipicolinic acid (H₂dpa), salicylic acid (HSAL) in water and ethanol at 140 °C for 5 days yields a novel 3D coordination polymer NaCr(C₇H₃O₄N)₂(H₂O)₂ (1). In the complex, each Cr center is in a distorted octahedral environment, and coordinates to two nearly perpendicular dpa anions, which act as tridentate ligands. Na(I) is in a compact sixfold coordination with three non-coordination carbonyl oxygen atoms of neighboring asymmetric units, a carboxylate oxygen atom shares coordination with Cr(III) and two aqueous. Two adjacent asymmetric units are linked together through Na–O and a set of intermolecular hydrogen bonds, which generates the finally 3D supermolecular network structure.     

Hydrothermal synthesis,crystal structure,and thermal stability of a novel 3D cadmium phosphonate with double-stranded helical channels

In the presence of ethylenediamine template agents, a novel 3D cadmium phosphonate with double-stranded helical channels, [enH₂]_0.5[Cd₂(HL)(L)] 1(H₃L =  2-hydroxyphosphonoacetic acid; en = ethylenediamine) has been synthesized by hydrothermal reaction at 140 °C and characterized by single-crystal X-ray diffraction as well as by infrared spectroscopy, elemental and thermogravimetric analysis. The structure of compound 1 comprises right-handed double-stranded helical channels, left-handed double-stranded helical channels and achiral channels that are connected through cadmium atoms and L³⁻ligands to form a meso compound, and the protonated ethylenediamine cations are located inside the achiral channels.     

Solvothermal synthesis,crystal structure and magnetic properties of a 3D CoII framework based on 2-p-isopropylphenyl imidazole dicarboxylate

Self-assembly of CoSO₄ salt and 2-(p-isopropylphenyl)-1H-imidazole-4,5-dicarboxylic acid (H₃PPhIDC), results in the formation of a metal-organic framework, [Co(HPPhIDC)(CH₃OH)]_n (1), which has been characterized by elemental analysis, IR, X-ray powder diffraction (XRPD), thermogravimetric analysis and single-crystal X-ray diffraction. Polymer 1 is a meso-compound and displays a (3,3)-connected 3D structure with 1D channels and cages, which are composed of left- and right-handed helices pillared by Co^2 + linkers. Moreover, the antiferromagnetic coupling between the neighboring Co(II) ions in 1 can be observed.     

Hydrothermal synthesis,crystal structure and electrochemical property of a novel 3-D microporous reduced molybdophosphate with large cavities

A novel molybdenum phosphate based on [Mo₆P₄] inorganic subunits and [Mn(H₂O)₂]²⁺ cations, Mn[Mo₆O₁₂(OH)₃(PO₄)(HPO₄)₂(H₂PO₄)]₂[Mn(H₂O)₂]₂(Hen)₄·13H₂O (en = ethyl enediamine), has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, IR spectroscopy, EPR spectrum and TGA analysis. The 3-D framework of the compound contains microporous structure with large cavities filled by mono-protonated Hen⁺ and water molecules. The electrochemical behavior of the compound has been also studied.     

Synthesis,structure, and adsorption properties of a three-dimensional porous yttrium–organic coordination network

Deprotonation of 4,4′-biphenyldicarboxylic acid (H₂BPDC) with triethylamine followed by the copolymerization with Y(III) in N,N-dimethylformamide (DMF) at room temperature yields a new three-dimensional (3-D) porous metal–organic coordination network, [Y₂(BPDC)₃(DMF)₂(H₂O)₂]_n · (DMF)_n · (H₂O)_n (1). Compound 1 (C_24.50H₁₉N_1.50O₉Y) crystallizes in the triclinic P-1 space group (a = 8.220 (2), b = 13.998 (4), c = 14.212 (4) Å, α = 111.058 (5)°, β = 90.187 (5)°, γ = 94.318 (5)°, V = 1520.9 (7) ų, and Z = 2). X-ray crystallography reveals that 1 consists of a 3-D framework contained open 1-D channels with the dimension of 5 × 10 Å along the crystallographic a axis. The adsorption measurements show that compound 1 can adsorb N₂, Ar and CO₂ into its pores. The adsorption isotherms for MeOH and H₂O were also measured.     

Effect of dysprosium substitution on crystal structure and physical properties of multiferroic BiFeO3 ceramics

The polycrystalline samples of multiferroic Bi_1−xDy_xFeO₃ (x = 0, 0.1, and 0.2) were prepared by a modified solid state reaction method and characterized by X-ray diffraction, scanning electron microscopy, differential thermal analysis, dielectric and magnetic measurements. It was shown that the introduction of the Dy³⁺ ions stabilizes the perovskite structure and improves phase purity. The coexistence of the rhombohedral and orthorhombic phases was found to exist within the investigated concentration range 0.1 ≤ x ≤ 0.2. The changes and anomalies observed in dielectric response over a wide frequency range were correlated with the structural evolution and the development in microstructure. The SQUID measurements of the field-dependent magnetization at different temperatures demonstrated Dy doping to be a very effective method for inducing a weakly ferromagnetic state in the ferroelectric R3c phase of BiFeO₃ in the absence of an external magnetic field.     

一种三维微孔磷酸钼材料的水热合成与表征

本文采用水热合成法,在Mo-P-二乙烯三胺(DETA)-H2O体系中,合成出了一种具有类似于已知三维微孔结构的磷酸钼材料(NH4)3Mo4P3O16的MoPO-DETA.分别考察了DETA/P、P/Mo、晶化温度等影响因素对产物的影响,并对样品进行了XRD,TG-DTA等表征.结果表明,在210℃、DETA/P为0.42～0.75、P/Mo为1.5～3.5、晶化3天的条件下,合成出结晶度和纯度高的磷酸钼材料MoPO-DETA.     

Binary ionic porphyrin nanosheets: electronic and light-harvesting properties regulated by crystal structure

Crystalline solids self-assembled from anionic and cationic porphyrins provide a new class of multifunctional optoelectronic micro- and nanomaterials. A 1?:?1 combination of zinc(II) tetra(4-sulfonatophenyl)porphyrin (ZnTPPS) and tin(IV) tetra(N-methyl-4-pyridiniumyl)porphyrin (SnTNMePyP) gives porphyrin nanosheets with high aspect ratios and varying thickness. The room temperature preparation of the nanosheets has provided the first X-ray crystal structure of a cooperative binary ionic (CBI) solid. The unit cell contains one and one-half molecules of aquo-ZnTPPS(4-) (an electron donor) and three half molecules of dihydroxy-SnTNMePyP(4+) (an electron acceptor). Charge balance in the solid is reached without any non-porphyrinic ions, as previously determined for other CBI nanomaterials by non-crystallographic means. The crystal structure reveals a complicated molecular arrangement with slipped π-π stacking only occurring in isolated dimers of one of the symmetrically unique zinc porphyrins. Consistent with the crystal structure, UV-visible J-aggregate bands indicative of exciton delocalization and extended π-π stacking are not observed. XRD measurements show that the structure of the Zn/Sn nanosheets is distinct from that of Zn/Sn four-leaf clover-like CBI solids reported previously. In contrast with the Zn/Sn clovers that do exhibit J-aggregate bands and are photoconductive, the nanosheets are not photoconductive. Even so, the nanosheets act as light-harvesting structures in an artificial photosynthesis system capable of reducing water to hydrogen but not as efficiently as the Zn/Sn clovers.     

不同晶型纳米二氧化钛的水热合成

水热法合成了不同晶型、形貌和大小的纳米二氧化钛。利用X射线衍射(XRD)和透射电镜(TEM)对所得的样品进行了表征。研究了pH值、水热反应温度和水热反应时间对纳米二氧化钛晶型、形貌和晶粒尺寸的影响。结果表明,前驱体pH值是决定产品晶型、晶粒尺寸和形貌的主要因素。随着水热反应温度的升高,纳米二氧化钛的晶粒尺寸逐渐变大,但pH=3.0时所形成的锐钛矿型纳米二氧化钛的晶粒尺寸却几乎不变;随着水热反应时间的延长,金红石型纳米二氧化钛晶粒的生长速度最快,而锐钛矿型的纳米二氧化钛的晶粒生长速度则最慢。     

新型杂环Schiff碱的合成、晶体结构及荧光性质研究

以3-甲基-2-噻吩甲醛和4-氨基安替比林为原料合成了一种新的schiff碱--1,5-二甲基-4-[(3-甲基噻吩-2-亚甲基)氨基]-2-苯基-1,2-二氢吡唑-3-酮,采用IR、元素分析法、NMR及X-射线单晶衍射法对其结构进行了表征.该化合物属于正交晶系,P212121空间群,晶胞参数a=0.697 81(6)...     

Synthesis and optical properties of a series of thermally stable diphenylanthrazolines

A series of diphenylanthrazolines were synthesized by Friedländer condensation of 2,5-dibenzoyl-1,4-phenylenediamine and acetyl-functionalized compounds in the presence of polyphosphoric acid as catalyst, in yields ranging from 61% to 88%. The diphenylanthrazolines are thermally robust with high decomposition temperatures (>380.0 °C) and high melt transitions (317–462 °C). All of them show the lowest energy absorption bands (λ_max^Abs: 394–433 nm) from the π–π¹ transitions by virtue of their large molar extinction coefficients (? ≈ 10⁴ M^?1 cm^?1), revealing low optical band gaps (2.59–2.80 eV). The compounds emit blue fluorescence with λ_max^Em ranging from 430 to 466 nm in dilute toluene solution.     

Hydrothermal synthesis and crystal structure of the first Keggin polyoxometalate supported cadmium coordination complex

A new compound [(BW₁₂O₄₀)Cd(2,2′-bpy)₂(H₂O)][Cd(2,2′-bpy)₃]_1.5·0.5H₂O (1) has been hydrothermally synthesized and characterized by IR, UV–Vis, XPS spectrum, TG, XRD, elemental analysis and single crystal X-ray diffraction analysis. Crystal structure analysis reveals that 1 is the first Keggin polyoxoanion supported cadmium coordination complex.     

Hydrothermal synthesis and crystal structure of a novel Keggin polyoxoanion-templated multichain coordination polymer with a flexible bis(imidazole) ligand

By introducing the flexible 1,1′-(1,4-butanediyl)bis(imidazole) (bbi) ligand into the Keggin system, a novel multi-chain compound, (bbi)_1.5[Cu(bbi)]_4.5[PW₁₂O₄₀]_1.5 (1) was synthesized under the hydrothermal conditions. It was characterized by elemental and TG analysis, IR and XPS spectra, cyclic voltammetry, powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. Compound 1 features in two sorts of polyoxometalates (POMs) chains, the poly-chain of [Cu(bbi)]_4.5[PW₁₂O₄₀] and the single-chain of (bbi)[PW₁₂O₄₀]_0.5, induced by the POM clusters.     

High-pressure synthesis,crystal structure,and physical properties of NaAlB14 single crystals

Pure NaAlB₁₄ single crystals were successfully synthesized directly from Na, Al, and B at high pressure and high temperature, different from the previously reported method, that is, synthesized from Na₂B₄O₇, Al, and B. The growth of NaAlB₁₄ single crystals was promoted by increasing the reaction temperature. The atomic structures of NaAlB₁₄ single crystal along the [100], [010], [001], and [021] axes were characterized by using a scanning transmission electron microscope. The Raman spectra of NaAlB₁₄ were investigated theoretically and experimentally, and they showed the expected oscillations of the covalent framework. In addition, photoluminescence spectra indicated that NaAlB₁₄ is a semiconductor luminescence material with red (1.68 eV) and near-infrared (1.50 and 1.36 eV) emission characteristics. The band structure revealed that NaAlB₁₄ is an indirect band gap semiconductor with a wide band gap of 2.22 eV.     

The synthesis,crystal structure and photophysical properties of three novel naphthalimide dyes

Three new naphthalimide derivatives containing an electron-donor moiety (carbazole), 4-carbazolyl-N-methyl-1,8-naphthalimide, 4-carbazolyl-N-cyclohexyl-1,8-naphthalimide and 4-carbazolyl-N-phenyl-1,8-naphthalimide were synthesized and crystal structures confirmed. Crystallographic data revealed that the interplanar angles (θ) of the carbazole and naphthalimide moieties were, respectively, 70.7° and 66.5°. The UV–vis absorption and photoluminescent spectra of the systems in n-hexane, CHCl₃, tetrahydrofuran and CH₂Cl₂ were investigated. The lowest absorption band of the naphthalimide molecular centered at 400–420 nm was assigned to charge-transfer transition with emission at ≈440 nm in n-hexane and at ≈560 nm in CH₂Cl₂.     

Hydrothermal synthesis and structure of di-copperII-complex substituted monovacant polyoxotungstate with a 1D chain structure

A novel di-copper^II-complex substituted monovacant Keggin polyoxotungstate [Cu(2,2′-bpy)(H₂O)][H₂PW₁₁O₃₉Cu₂(2,2′-bpy)₂(H₂O)(OH)] · 1.5H₂O (1) (2,2′-bpy = 2,2′-bipyridine) with a 1D polymeric chain has been hydrothermally synthesized and structurally characterized. To our knowledge, 1 is the rare magnetic di-transition metal-complex substituted monovacant Keggin polyoxotungstate with a unique 1D dual-bridging chain structure. Its magnetic behavior has been quantitatively analyzed by the Bleaney–Bowers equation, indicating the presence of weak antiferromagnetic interactions within dinuclear Cu^II centers.     

Hydrothermal synthesis and crystal structure of oxamidato-bridged pentanuclear CuII4LaIII complex containing macrocyclic ligand

A novel oxamidato-bridge Cu^II₄La^III pentanuclear complex incorporating a macrocyclic oxamide of formula [(CuL)₃(CuLC₂H₅OH)La(H₂O)](ClO₄)₃·1.5H₂O has been hydrothermally synthesized, spectroscopically, structurally, and magnetically characterized.     

Hydrothermal evolution, optical and electrochemical properties of hierarchical porous hematite nanoarchitectures

Hollow or porous hematite (α-Fe₂O₃) nanoarchitectures have emerged as promising crystals in the advanced materials research. In this contribution, hierarchical mesoporous α-Fe₂O₃ nanoarchitectures with a pod-like shape were synthesized via a room-temperature coprecipitation of FeCl₃ and NaOH solutions, followed by a mild hydrothermal treatment (120°C to 210°C, 12.0 h). A formation mechanism based on the hydrothermal evolution was proposed. β-FeOOH fibrils were assembled by the reaction-limited aggregation first, subsequent and in situ conversion led to compact pod-like α-Fe₂O₃ nanoarchitectures, and finally high-temperature, long-time hydrothermal treatment caused loose pod-like α-Fe₂O₃ nanoarchitectures via the Ostwald ripening. The as-synthesized α-Fe₂O₃ nanoarchitectures exhibit good absorbance within visible regions and also exhibit an improved performance for Li-ion storage with good rate performance, which can be attributed to the porous nature of Fe₂O₃ nanoarchitectures. This provides a facile, environmentally benign, and low-cost synthesis strategy for α-Fe₂O₃ crystal growth, indicating the as-prepared α-Fe₂O₃ nanoarchitectures as potential advanced functional materials for energy storage, gas sensors, photoelectrochemical water splitting, and water treatment.