Crystal Structure, Thermal and Magnetic Behavior of Inorganic–Organic Hybrid [VIV 4O10 VV 2O4] (C6H14N2)·H2O Polymeric Framework

Summary The inorganic–organic hybrid [V^IV ₄O₁₀V^V ₂O₄] (C₆H₁₄N₂)·H₂O polymeric framework was prepared under mild hydrothermal conditions from a mixture of DABCO and V₂O₅ in deionized water with a 1:1:450 mole ratio, at neutral pH. The reaction was carried out at 180 °C for 3 days under autogenous pressure yielding phase pure crystals product. The crystal structure was studied using both powder and single crystal X-ray crystallography, revealing the structure to be of the ({UuDd}:T*)α′ type in the SP+T class and Z-T subclass. The presence of the organic cation was confirmed by FT-IR spectrum and chemical composition analysis. The structure was thermally stable up to over 400 °C, and showed ferromagnetic character at room temperature with the maximum molar susceptibility of 8.26 × 10⁻³ emu/mol⁻¹ at zero applied field.     

Hydrothermal Crystal Growth,Structures and Thermal Properties of Co(II)-4,4′-bipyridine-Based Coordination Polymeric Materials

Hydrothermal synthetic parameters were studied and optimized for the preparation of new coordination polymeric materials based on Co(II) and 4,4′-bipy. A new polymeric compound, [Co₂(H₂O)₂(OH)₂(4,4′-bipy)₈](NO₃)₂·2(4,4′-bipy) 10(H₂O) (1), was prepared and structurally characterized by single crystal experiment. The framework of (1) is made up of two different one-dimensional substructures, i.e., the neutral chain A and positively charged chain B, both of which share the same nodes and node linkers. This is rarely found, especially from a one-pot crystal growth technique. Two other crystals were also identified, i.e., [Co(SO₄)(H₂O)₃(4,4′-bipy)]·2(H₂O), and K₂Co(H₂O)₆(SO₄)₂. The optimization of synthetic parameters apparently favors the formation of different polymeric structures, and this can be experimentally fine tuned. The influences of these parameters on phase formation, purity and crystal growth are discussed. The complicated thermogravimetric property of the new compound is also reported.     

A Novel 3D Europium (III) Coordination Polymer Constructed from 3,5-Pyridinedicarboxylate Acid: Synthesis, Crystal Structure and Emission Spectrum

Abstract  A novel 3D coordination polymer Eu₂(PDC)₃(H₂O)₃ (1) has been synthesized by hydrothermal reaction of europium chloride with 3,5-pyridinedicarboxylate acid (H₂PDC) under acidic condition (pH 2–3). Complex 1 is a 3D coordination polymer via 1D infinite chains built by the pyridinium moieties of the PDC²⁻ anions. The thermal analyses and luminescent properties of 1 have also been investigated. Graphical Abstract   A novel 3D coordination polymer Eu₂(PDC)₃(H2O)₃ has been synthesized by hydrothermal reaction of europium chloride with 3,5-pyridinedicarboxylate acid under acidic conditions (pH 2–3). The formation of the title complex demonstrates that pH plays an important role during the synthesis.      

笼型倍半硅氧烷基聚合物的制备和结构性能以及应用

笼型倍半硅氧烷基聚合物是一种典型的多面体有机／无机分子复合物材料,因其具有优异的光、电、热、磁、声、力学和化学相容性等性能,所以近年来被引入较为尖端的技术领域进行研究和应用。本文归纳总结了笼型倍半硅氧烷基聚合物的现行制备方法,讨论了笼型倍半硅氧烷结构对材料性能的影响。最后,对笼型倍半硅氧烷基聚合物材料的应用领域和发展趋势进行了说明。     

Structural dependence of microwave dielectric properties of spinel structured Mg2(Ti1-xSnx)O4 solid solutions: Crystal structure refinement,Raman spectra study and complex chemical bond theory

Mg₂(Ti_1-xSn_x)O₄ (x?=?0–1) ceramics were prepared through conventional solid-state method. This paper focused on the dependence of microwave dielectric properties on crystal structural characteristics via crystal structure refinement, Raman spectra study and complex chemical bond theory. XRD spectrums delineated the phase information of a spinel structure, and structural characteristic of these compositions were achieved with the help of Rietveld refinements. Raman spectrums were used to depict the correlations between vibrational phonon modes and dielectric properties. The variation of permittivity is ascribed to the Mg₂(Ti_1-xSn_x)O₄ average bond covalency. The relationship among the B-site octahedral bond energy, tetrahedral bond energy and temperature coefficient are discussed by defining on the change rate of bond energy and the contribution rate of octahedral bond energy. The quality factor is affected by systematic total lattice energy, and the research of XPS patterns illustrated that oxygen vacancies can be effectively restrained in rich oxygen sintering process. Obviously, the microwave dielectric properties of Mg₂(Ti_1-xSn_x)O₄ compounds were obtained (${\epsilon }_r$= 12.18, $Q\times f$?=?170,130?GHz, ${\tau }_f$?=??53.1?ppm/°C, x?=?0.2).     

Solvothermal Synthesis,Crystal Structure and DNA Binding Studies of a 3D Supramolecular Complex {[Cu(phen)CN][Cu(phen)][Cu(CN)<Subscript>2</Subscript>]}<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript> Assembled by Double Curvy Chains

A new cyano-bridged copper (I) complex {[Cu(phen)CN][Cu(phen)][Cu(CN)₂]} _n (1) (phen = 1,10-phenanthroline) was synthesized under the solvothermal conditions, and characterized by elemental analysis, FI-IR spectra and single-crystal X-ray diffraction. The structure analysis reveals that complex 1 contains two [Cu(phen)CN][Cu(phen)][Cu(CN)₂] subunits, being, respectively, constructed into two chains with different cyano backbones. The resulting chains offer a double curvy chain by Cu···Cu weak interactions and π–π stacking interactions. It is exciting that the double curvy chains adopt anti-parallel array and result in a novel 3D architecture through π–π stacking interactions. According to the supramolecular self-assembly of complex 1, four types of stacking mode of phenanthroline moieties are given and discussed. Absorption and fluorescence titration studies of complex 1 with calf thymus DNA are suggestive of the intercalation binding mode with a intrinsic binding constant of 7.52 × 10³ M⁻¹ and a linear Stern-Volmer quenching constant of 1.02 × 10⁵ M⁻¹.     

Concomitant Crystallization of Copper(II) Sachharinato Complexes with 2-methylpyrazine as a Monomer and an One-dimensional Polymer: Syntheses,Crystal Structures,Spectroscopic and Thermal Properties

The reaction of [Cu(sac)₂(H₂O)₄] · 2H₂O with 2-methylpyrazine (mpyz) leads two complexes, concomitant crystallization of a mononuclear complex [Cu(sac)₂(mpyz)(H₂O)₂] (1) and a polymeric complex [Cu(sac)₂(μ-mpyz)]_n (2). Both complexes have been characterized by elemental analyses, magnetic measurements, FT-IR and ESR, TG-DTA and single-crystal X-ray diffraction analyses. Single-crystal X-ray analyses show that complex 1 consists of discrete molecules in which the copper(II) ions exhibits a square-pyramidal coordination geometry. The individual molecules of 1 are connected into a hydrogen-bonded chain structure, which is further assembled to form a three-dimensional network by π–π stacking interactions. Complex 2 is an 1D coordination polymer in which copper(II) centers are bridged by the mpyz ligand. The chains are further assembled to form two-dimensional frameworks by π–π and C–H···π stacking interactions.     

复合助熔剂对BaMgAl10O17∶Eu2+蓝色荧光粉晶体结构、颗粒形貌及发光性能的影响

采用先烧结后还原的高温固相法制备了BaMgAl10O17∶Eu2+ (BAM)蓝色荧光粉,研究了H3BO3+BaF2、H3 BO3+AlF3、BaF2+AlF33种不同组合的复合助熔剂对BAM蓝色荧光粉的物相纯度、颗粒形貌及发光性能的影响.结果表明:以H3BO3+BaF2为复合助熔剂的蓝粉与其它2种复合助熔剂制备的样品...     

5-(4-叠氮呋咱基)-[1,2,3]三唑[4,5-c]并呋咱内盐的合成、晶体结构及性能

以3,4-二氨基呋咱为原料,经重氮化-叠氮化、氧化-环化等反应合成了一种新型无氢富氮含能材料5-(4-叠氮呋咱基)-[1,2,3]三唑[4,5-c]并呋咱内盐(AFTF);采用红外光谱、核磁共振、元素分析等方法表征了目标物的结构;获得了AFTF的单晶并进行了晶体结构解析;采用DSC方法研究了AFTF的热稳定性,初步探讨了氧化-环化反应机理;采用Gaussian 09程序CBS-QB3方法计算了AFTF的固相生成热,基于晶体密度和固相生成热,利用EXPLO5爆轰软件预估了AFTF的爆轰性能。结果表明,化合物AFTF晶体为正交晶系,空间群为P 2(1)2(1)2(1),晶胞参数为:a=8.1782(17),b=8.6446(18),c=11.521(2),V=814.5(3)3,Z=4,μ=0.151 mm^-1,F(000)=440;AFTF的熔点为101.02℃,热分解温度为186.39℃;AFTF晶体密度为1.795 g/cm 3(296 K),氮含量为63.6%,理论爆速为8.982 km/s,爆压为33.5 GPa,生成热为1178.9 kJ/mol,爆热为6450.8 kJ/kg,表明AFTF是一种爆轰性能优良的无氢富氮高能量密度化合物,有望应用于高能推进剂或气体发生剂领域;低熔点特性有望使其作为熔铸炸药载体使用。