功能性配位材料脱除湿法磷酸中砷的研究

利用功能性配位材料高选择性和高靶向性的抓捕能力,对湿法磷酸中的砷杂质进行脱除。采用单因素实验,系统考察了材料用量、温度、时间、搅拌速度对砷杂质去除率的影响,并得到了最佳的脱砷条件。结果表明,当酸用量是功能性材料的400倍,反应温度为60℃,搅拌速度为200r·min^(-1),搅拌时间为4h,湿法净化磷酸中的砷含量可从1083μg·kg^(-1)降到101.08μg·kg^(-1),脱砷率达到90.67%。与传统磷酸硫化钠脱砷法相比,采用此法进行磷酸脱砷,具有高效、安全、易操作等优点,在低浓度残留量时仍可高效吸附,且吸附后不脱落,同时过程中也不会引入新杂质,最终能实现磷酸中的砷从mg·kg^(-1)级别到μg·kg^(-1)级别的飞跃。

一个插指结构配位材料的制备与表征

以水热技术制备出一个镉配位材料[Cd(4-NO2-BDC)(bbi)(H2O)]n·n H2O(4-NO2-BDC2-=4-硝基-邻苯二甲酸阴离子,bbi=1,4-二咪唑基丁烷).运用单晶X-射线衍射仪、元素分析和红外光谱对材料结构进行表征.研究结果,这种镉配位材料是不寻常的2D→3D插指结构,材料属于三斜晶系,P-1空间群.晶格参数为:a=0. 874 8(5) nm,b=0. 947 1(5) nm,c=1. 310 6(5) nm,α=102. 977(5)°,β=95. 480(5)°,γ=92. 174(5)°,V=0. 105 13(9) nm^3. Z=2,C_(18)H_(21)Cd N_5O_8,Mr=547. 8,Dc=1. 730 g/cm3. F(000)=552,R(int)=0. 016 7,R2=0. 025 2,ωR2=0. 064 5(I> 2σ(I)).

无机化学前沿综述

随着无机化学的研究方向和研究方法日益多样化,无机化学的研究前景越来越光明。本文从配位材料化学、无机固体化学、无机碳化学、新能源材料等几个方面阐述了无机化学研究的热点问题和前沿领域。

Anisotropic Lattice Strain of Composite Materials of LiMnO2 and H/D-Substituted Chiral Cyanide-Bridged Ni（Ⅱ）-Fe（Ⅲ） Coordination Polymers

Composite materials composed of LiMnO2, a typical electrode material for lithium ion battery, and a chiral cyanide-bridged Ni（Ⅱ）-Fe（Ⅲ） coordination polymer [NiL2][Fe（CN）6]·4H2O （Ni-Fe, H-form） （L = （1R,2R）-（-）-1,2-cyclohexane-diamine） or its deuterium isomer, [NiL2][Fe（CN）6]·4D2O （Ni-Fe, D-form） have been prepared by the various ratios （w/w） of Ni-Fe：LiMnO2 = 10：0 （pure Ni-Fe）, 9：1, 8：2, 7：3, 6：4, 5：5, 4：6, 3：7, 2：8, 1：9 and 0：10 （pure LiMnO2）. Gradual shift of IR （infrared） spectra by changing the ratios and losing difference between H-form and D-form of Ni-Fe due to isotope effects revealed adsorption of Ni-Fe onto LiMnO2 to form composite materials. Formation of composite materials of Ni-Fe and LiMnO2 could be also proved losing ferromagnetic behavior of LiMnO2 on increasing of the ratios of Ni-Fe in each composite. In contrast to smoothly positive thermal expansion of pure LiMnO2 along the crystallographic b axis, variable temperature powder XRD （X-ray diffraction） patterns at 100-300 K of the composite materials exhibited thermally-accessible lattice distortion along the b axis with different ratios. It is also proved deviation of ideal linear correlation of an evaluation function, In K = a/T ＋ b （where, K = （d（T） - d（0））/d（T）, d（T） denotes nλ/（sin 2θ） at T （K））.

Nonlinear optical material of a low-dimensional coordination polymer:Synthesis,structure,NLO and fluorescence properties

Employing unsymmetrical 2-mercapto-5-methyl-1,3,4-thiadiazole and 2,2′-bipyridine as mixed ligands, a new low-dimensional coordination polymer [Zn(MMTA) 2 (2,2′-bipy)] n (MMTA = 2-mercapto-5-methyl-1,3,4-thiadiazole, 2,2′-bipy = 2,2′-bipyridine), has been synthesized under solvothermal condition and characterized by single crystal X-ray diffraction. This compound crys- tallizes in the noncentrosymmetric space group Cc, with cell parameters: a = 8.291(4) , b = 15.483(9) , c = 15.620(6) , = 96.00(5)°, V = 1994.1(2) 3 , and Z = 4. The mixed ligands link the zinc center into a mononuclear unit, which is futher linked by weak C-H···N and C-H···S hydrogen bonds into a three-dimensional noncentrosymmetric framework. The compound exhibits intense photoluminescence and distinct NLO properties at room temperature. The intensity of the green light produced by the powder sample of the compound is about 3.2 times that produced by KDP powder. On the basis of the results of TG analysis, the structure is thermally stable up to ～260 °C.

Self-assembled energetic coordination polymers based on multidentate pentazole cyclo-N_5^-

Coordination to form polymer is emerging as a new technology for modifying or enhancing the properties of the existed energetic substances in energetic materials area. In this work, guanidine cation CN3 H6+ (Gu) and 3-amino-1,2,4-triazole C2H4N4(ATz) were crystallized into NaN5 and two novel energetic coordination polymers(CPs),(NaN5)5[(CH6-N3)N5](N5)3–(1) and(NaN5)2(C2H4N4)(2) were prepared respectively via a self-assembly process. The crystal structure reveals the co-existence of the chelating pentazole anion and organic component in the solid state. In polymer 1, Na+and N5– were coordinated to form a cage structure in which guanidine cation [C(NH2)3]+ was trapped;for polymer 2, a mixedligand system was observed;N5 – and ATz coordinate separately with Na+and form two independent but interweaved nets. In this way, coordination polymer has been successfully utilized to modify specific properties of energetic materials through crystallization. Benefiting from the coordination and weak interactions, the decomposition temperatures of both polymers increase from 111°C(1D structure [Na(H2 O)(N5)]?2 H2 O) to 118.4 and 126.5°C respectively. Moreover, no crystallized H2 O was generated in products to afford the anhydrous compounds of pentazole salts with high heats of formation( >800 kJ mol–1). Compared to traditional energetic materials, the advantage in heats of formation is still obvious for the cyclo-N5– based CPs, which highlights cyclo-N5– as a promising energetic precursor for high energy density materials(HEDMs).

Au NP@silica@europium coordination polymer nanocomposites for enhanced fluorescence and more sensitive monitoring reactive oxygen species

Au nanoparticle（Au NP）@SiO2@TDA-Eu nanocomposites were prepared by a two-step process： Au NP@SiO2 nanocomposites were prepared by a modified onepot process. Then the europium coordination polymer was deposited on the surface of the Au NP@SiO2 by mixing 2,2＇-thiodiacetic acid [S（CH2 COO）2^（2-）, TDA] and Eu（NO3）3·6 H2 O in ethanol via a hydrothermal method. The maximum fluorescent enhancement factor of the nanocomposites was 6.81 at 30 nm thickness of silica between the core of the Au NP and the shell of TDA-Eu. The prepared nanocomposites exhibit more sensitive monitoring of reactive oxygen species.