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1.
以多齿席夫碱配体H2L(H2L=(E)-N′-(3-乙氧基-2-羟基亚苄基)-3-羟基吡啶甲酰肼)为配体,与Ln(acac)3·2H2O(Ln=Tb、Ho、Er;acac-=乙酰丙酮根)反应,通过溶剂热法,成功得到了3例新的双核稀土配合物[Ln2(acac)2(L)2(C2H5OH)2](Ln=Tb((1)、Ho((2)、Er(3))。单晶X射线衍射分析表明:配合物1~3的结构主要由2个Ln离子、2个乙酰丙酮根(acac-)、2个L2-及2个C2H5OH组成,中心Ln离子通过2个μ2-O原子相互连接,形成一个平行四边形的Ln2O2核心。固体荧光实验测...  相似文献   

2.
使用多齿席夫碱配体H2L与Yb(acac)3·2H2O反应,设计并通过溶剂热法合成了一例结构新颖的八核镱簇合物[Yb8(acac)4(HL)4(L)23-O)4(C2H5O)4]·2C2H5OH·2CH2Cl2 (1)。单晶 X 射线衍射分析表明,簇合物呈中心对称的八核结构,中心稀土离子Yb1(Ⅲ))为八配位的双帽三角棱柱几何构型,Yb2、Yb3和Yb4均为七配位,分别为单帽三角棱柱、五角双锥及单帽八面体几何构型。簇合物1具有良好的溶剂稳定性。近红外荧光测试表明:簇合物1在室温下表现出Yb(Ⅲ)特征发射峰。此外,催化性质研究表明:簇合物1可以有效地催化CO2与环氧化合物的环加成反应,且作为异相催化剂表现出良好的循环性能。  相似文献   

3.
A microporous and robust bimetal-organic framework [Cd2Ba(NH2-BTB)2]·2(DMA)·2(H2O)(1) was constructed by mixing the heterometallic nodes and an tridentate carboxyl ligand with amino group, benefiting from the synergistic effect of active sites, exposed amino groups and ultramicroporous structure. This compound displays an extraordinary selectivity of CO2/CH4 and C2H2/CH4(16.7 and 146.3) at 298 K an...  相似文献   

4.
以N-(2-羟基-3-甲氧基亚苄基)氨基脲(H2hms)与不同取代基的羧酸(RCOOH)为配体,合成了3例席夫碱类的中心对称双核镝基配合物[Dy2(Hhms)2(C(CH3)3COO)2(H2O)4](NO3)2(1)、[Dy2(Hhms)2(C14H9COO)2(C2H5OH)2(CH3OH)2][ZnCl4](2)和[Dy2(Hhms)2(C6H3(NH2)2COO)2Cl2]·2CH3CN(3),并对其进行了结构和磁性表征。结构分析表明,配合物1和2保持了相似的单帽四方反棱柱配位构型,但1与2中羧酸与Dy(Ⅲ)键合的方式不同;配合物2和3保持了相似的酚氧和羧酸桥联结构,但由于配位小分子的不同,配合物3中Dy(Ⅲ)离子的配位几何构型与2有所不同。磁性测试结果表明,配合物3在零场下观察到显著的单分子磁体行为,具有磁翻转有效能垒96 K。相反,配合物1仅表现了快的量子隧穿弛豫行为,甚至配合物2没有单分子磁体的弛豫信号。借助结构特点和各向异性轴取向等关键信息,对3例配合物的磁构效关系进行了讨论。研究结果表明利用羧酸配体取代基能够实现对分子磁各向异性以及对称性的良好调控,从而提高镧系单分子磁体磁弛豫行为。  相似文献   

5.
An organic-inorganic hybrid Fe–Pr-included 2-germano-20-tungstate [Pr(H2O)8]2H2[Fe4(H2O)4(pca)4Ge2W20O72]·34H2O(Hpca=2-pyridinecarboxylic acid)(1) was hydrothermally prepared. Its polyoxoanion comprises one tetra-Fe incorporated [Fe4(H2O)4(pca)4Ge2W20O72]...  相似文献   

6.
使用多齿希夫碱配体通过溶剂热的方法合成了一例新的Ho4配合物,即[Ho4(NO3)2(acac)4(L)2(CH3OH)2]·2CH3CN,其中H4L=(E)-2-(羟甲基)-2-(((2-羟基萘-1-基)亚甲基)氨基)丙烷-1,3-二醇,acac=乙酰丙酮。X射线衍射分析表明,配合物呈中心对称的四核结构,中心的Ho1(Ⅲ)和Ho2(Ⅲ)均为八配位的三角十二面体几何构型。配合物1具有良好的溶剂稳定性。磁性研究表明配合物1具有慢磁弛豫行为。据我们所知,配合物1是一例少有的在零直流场下具有慢磁驰豫行为的Ho4配合物。值得一提的是,配合物1在催化CO2与环氧化合物的环加成反应中表现出较高的催化活性。  相似文献   

7.
合成了2,5-二甲氧基-N,N'-双(4-吡啶基)对苯二甲酰胺(简称为dmbpt), 并以其和1,3,5-苯三甲酸(简称为H3btc)为配体合成了2个新配合物[Cd2(dmbpt)2(Hbtc)2]·2DMF·C2H7N·H2O(1)和[Cd3(dmbpt)2(btc)2]·4H2O(2). 配合物1是具有3,5L2拓扑的二维金属有机骨架; 配合物2是具有jcr7拓扑的三维金属有机骨架, 这是一个稀有的拓扑结构. 配合物1和2都含有二级结构单元Cd2(—COO)4(—Py)4. 在结构关系上, 配合物2的三维网络可以看作是由配合物1的二维网络通过形成新的配位键连接而成的. 在原料和溶剂相同的溶剂热反应条件下, 能以不同比例同时获得2种配合物. 产物中配合物1和配合物2的比例可以通过改变反应物的浓度来调控, 这可能与由DMF分解产生的二甲胺促进H3btc的去质子化有关.  相似文献   

8.
Two fluoride sulfates,K2Mn3(SO4)3F2·4H2O(Ⅰ) and Rb2Mn3(SO4)3F2·2H2O (Ⅱ) are obtained by water solution method.Single-crystal X-ray diffraction analysis indicated that they crystallize in space groups of Cmc21.Their structures feature a pseudo-KTP structure consisting of interconnecting[Mn3(SO4)3F2(H2O)2] layers,which are further packing along the a axis with alkali metal cations balancing the charges.The structure relationships between the two compounds are discussed.Secondharmonic generation measurements manifest that Ⅰ and Ⅱ have similar second-harmonic generation responses of about 0.2 and 0.25 times that of KH2PO4.  相似文献   

9.
四核钴羰基簇合物的合成和晶体结构   总被引:1,自引:0,他引:1  
用Co2(CO)8与有机杂环二硫代次膦酸盐SP(C6H4OR)(S)N(C6H5)NC(Me)(R=Me,Et)反应,得到两类4个含S,P桥基配体的四核钴羰基簇合物Co4(CO)104-S)[μ4-P(C6H4OR)](1:R=Me;3:R=Et)和Co4(CO)103-S)[μ2-P(C6H4OR)N(C6H5)NC(Me)](2:R=Me,4:R=Et).在反应中,前配体中的PS键以及C-S,P-S,P-N键劈开,产生的分子片与金属钴原子配位,组建成新的羰基钴簇.对这4个簇合物进行了元素分析,IR,1HNMR和MS谱学表征,并测定了簇合物4的晶体结构,该晶体属单斜晶系,P21/c空间群,晶胞参数a=1.9065(4)nm,b=1.0081(2)nm,c=1.6663(3)nm,β=97.36(3)°,V=3.1704(11)nm3,Z=4,Dc=1.743g/cm3.Co1Co3Co4呈三角形分布,其中Co-Co平均键长为0.251nm,而Co2在该三角平面的一侧,Co2-Co3键为0.269nm.该簇合物分子骨架为三角钉型结构,每个Co原子的立体几何均为变形八面体,但配位环境各不相同.  相似文献   

10.
于220℃水热晶化下制备了高结晶度的γ-ZrP,合成了3种γ-苄基膦酸-磷酸锆层状化合物Zr(PO4).(H2PO4)0.15(C6H5CH2PO3H)0.85·0.4H2O(1,d=1.86nm),Zr(PO4)(H2PO4)0.30(C6H5CH2PO3H)0.70·0.6H2O(2,d=1.78nm)和Zr(PO4)(H2PO4)0.50(C6H5CH2PO3H)0.50·0.7H2O(3,d=1.66nm).用X射线粉末衍射和31P固态核磁共振等手段表征其结构,并研究了其与α-苯乙胺的插层性能.  相似文献   

11.
The double perovskites La2CoVO6, La2CoTiO6, and La2NiVO6, are described. Rietveld fitting of neutron and powder X-ray diffraction data show La2NiVO6 and La2CoVO6 to have a disordered arrangement of B-cations whereas La2CoTiO6 shows ordering of the B-cations (with ∼5% Co/Ti inversion). Curie-Weiss fits to the linear region of the 1/χ plots reveal Weiss temperatures of −107, −34.8, and 16.3 K for La2CoVO6, La2CoTiO6, and La2NiVO6, respectively, and magnetic transitions are observed. La2CoTiO6 prepared by our method differs from material prepared by lower-temperature routes. A simple antiferromagnetic spin model is consistent with the data for La2CoTiO6. These compounds are semiconductors with bandgaps of 0.41 (La2CoVO6), 1.02 (La2CoTiO6) and 0.45 eV (La2NiVO6).  相似文献   

12.
The two new compounds, Sr4Cu3(AsO4)2(AsO3OH)4·3H2O (1) and Ba2Cu4(AsO4)2(AsO3OH)3(2), were synthesized under hydrothermal conditions. They represent previously unknown structure types and are the first compounds synthesized in the systems SrO/BaO-CuO-As2O5-H2O. Their crystal structures were determined by single-crystal X-ray diffraction [space group C2/c, a=18.536(4) Å, b=5.179(1) Å, c=24.898(5) Å, β=93.67(3)°, V=2344.0(8) Å3, Z=4 for 1; space group P42/n, a=7.775(1) Å, c=13.698(3) Å, V=828.1(2) Å3, Z=2 for 2]. The crystal structure of 1 is related to a group of compounds formed by Cu2+-(XO4)3− layers (X=P5+, As5+) linked by M cations (M=alkali, alkaline earth, Pb2+, or Ag+) and partly by hydrogen bonds. In 1, worth mentioning is the very short hydrogen bond length, D···A=2.477(3) Å. It is one of the examples of extremely short hydrogen bonds, where the donor and acceptor are crystallographically different. Compound 2 represents a layered structure consisting of Cu2O8 centrosymmetric dimers crosslinked by As1φ4 tetrahedra, where φ is O or OH, which are interconnected by Ba, As2 and hydrogen bonds to form a three-dimensional network. The layers are formed by Cu2O8 centrosymmetric dimers of CuO5 edge-sharing polyhedra, crosslinked by As1O4 tetrahedra. Vibrational spectra (FTIR and Raman) of both compounds are described. The spectroscopic manifestation of the very short hydrogen bond in 1, and ABC-like spectra in 2 were discussed.  相似文献   

13.
用液相反应-前驱物烧结法制备了Cr2(WO4)3和Cr2(MoO4)3粉体。298~1 073 K的原位粉末X射线衍射数据表明Cr2(WO4)3和Cr2(MoO4)3的晶胞体积随温度的升高而增大, 本征线热膨胀系数分别为(1.274±0.003)×10-6 K-1和(1.612±0.003)×10-6 K-1。用热膨胀仪研究了Cr2(WO4)3和Cr2(MoO4)3在静态空气中298~1 073 K范围内热膨胀行为,即开始表现为正热膨胀,随后在相转变点达到最大值,最后表现为负热膨胀,其负热膨胀系数分别为(-7.033±0.014)×10-6 K-1和(-9.282±0.019)×10-6 K-1。  相似文献   

14.
研究了温度、时间、浓度等对A3钢片上Ni-P-Zn3(PO4)2、Ni-P-ZnSnO3和Ni-P-ZiSiO3纳米复合合化学镀层外貌的影响,用扫描电子显微镜(SEM)观察外貌、称重法测定厚度;通过10%NaCl溶液、1%H2S气体加速腐蚀试验,10%CuSO4溶液点滴试验等多种手段测定其耐腐蚀性能,用X-射线光电子谱(XPS)及俄歇电子能谱(SES)测定其价态组成,结果表明:在最佳施镀条件下,可得光亮、致密、耐腐蚀性强于A3钢、磷化膜及Ni-P镀层的纳米复合化学镀层,镀层的原子百分组成约为(%):Ni-P-Zn3(PO4)2:Ni70.00,P12.47,Zn3(PO4)213.93,C3.6;Ni-P-ZnSnO3;Ni77.56,P10.00,ZnSnO39.84,C2.6;Ni-P-NiSiO3,Ni83.00,P10.96,ZnSi5.15,C0.89.  相似文献   

15.
Single crystals of Ca3CuRhO6, Ca3Co1.34Rh0.66O6 and Ca3FeRhO6 were synthesized by high temperature flux growth in molten K2CO3 and structurally characterized by single crystal X-ray diffraction. While Ca3Co1.34Rh0.66O6 and Ca3FeRhO6 crystallize with trigonal (rhombohedral) symmetry in the space group , Z=6: Ca3Co1.34Rh0.66O6a=9.161(1) Å, c=10.601(2) Å; Ca3FeRhO6a=9.1884(3) Å, c=10.7750(4) Å; Ca3CuRhO6 adopts a monoclinic distortion of the K4CdCl6 structure in the space group C2/c, Z=4: a=9.004(2) Å, b=9.218(2) Å, c=6.453(1) Å, β=91.672(5). All crystals of Ca3CuRhO6 examined were twinned by pseudo-merohedry. Ca3CuRhO6, Ca3Co1.34Rh0.66O6, and Ca3FeRhO6 are structurally related and contain infinite one-dimensional chains of alternating face-sharing RhO6 octahedra and MO6 trigonal prisms. In the monoclinic modification, the copper atoms are displaced from the center of the trigonal prism toward one of the rectangular faces adopting a pseudo-square planar configuration. The magnetic properties of Ca3CuRhO6, Ca3Co1.34Rh0.66O6, and Ca3FeRhO6 are discussed.  相似文献   

16.
The compound previously reported as Ba2Ti2B2O9 has been reformulated as Ba3Ti3B2O12, or Ba3Ti3O6(BO3)2, a new barium titanium oxoborate. Small single crystals have been recovered from a melt with a composition of BaTiO3:BaTiB2O6 (molar ratio) cooled between 1100°C and 850°C. The crystal structure has been determined by X-ray diffraction: hexagonal system, non-centrosymmetric space group, a=8.7377(11) Å, c=3.9147(8) Å, Z=1, wR(F2)=0.039 for 504 unique reflections. Ba3Ti3O6(BO3)2 is isostructural with K3Ta3O6(BO3)2. Preliminary measurements of nonlinear optical properties on microcrystalline samples show that the second harmonic generation efficiency of Ba3Ti3O6(BO3)2 is equal to 95% of that of LiNbO3.  相似文献   

17.
This paper reports about two new hydrogen-containing rare-earth oxoborates RE4B6O14(OH)2 (RE=Dy, Ho) synthesized under high-pressure/high-temperature conditions from the corresponding rare-earth oxides, boron oxide, and water using a Walker-type multianvil equipment at 8 GPa and 880 °C. The single crystal structure determination of Dy4B6O14(OH)2 showed: Pbcn, a=1292.7(2), b=437.1(2), , Z=2, R1=0.0190, and wR2=0.0349 (all data). The isotypic holmium species revealed: Pbcn, a=1292.8(2), b=436.2(2), , Z=2, R1=0.0206, and wR2=0.0406 (all data). The compounds exhibit a new type of structure, which is built up from layers of condensed BO4-tetrahedra. Between the layers, the rare-earth cations are coordinated by 7+2 oxygen atoms. Furthermore, we report about temperature-resolved in situ powder diffraction measurements, DTA/TG, and IR-spectroscopic investigations into RE4B6O14(OH)2 (RE=Dy, Ho).  相似文献   

18.
采用水热合成法制备了Co3O4及复合Ag/Co3O4、CuO/Co3O4一维纳米产品。用XRD,FE-SEM和TEM手段对产品进行了表征。采用循环伏安法研究了合成产品修饰的玻碳电极在碱性溶液中对对硝基苯酚的电催化还原性能。与裸玻碳电极相比,1mmol·L-1的对硝基苯酚在用Co3O4、特别是CuO/Co3O4修饰的玻碳电极上还原的峰电流明显增大,用Ag/Co3O4(Ag/Co原子比分别为1∶5和2∶5)修饰的玻碳电极催化还原对硝基苯酚时,尽管还原峰电流增大不是太大,但其峰电位明显降低(分别降低0.265和0.371V)。  相似文献   

19.
An experimental study on the conversion of NO in the NO/N2, NO/O2/N2, NO/C2H4/N2 and NO/C2H4/O2/N2 systems has been carried out using dielectric barrier discharge (DBD) plasmas at atmospheric pressure. In the NO/N2 system, NO decomposition to N2 and O2 is the dominating reaction; NO conversion to NO2 is less significant. O2 produced from NO decomposition was detected by an on-line mass spectrometer. With the increase of NO initial concentration, the concentration of O2 produced decreases at 298 K, but slightly increases at 523 K. In the NO/O2/N2 system, NO is mainly oxidized to NO2, but NO conversion becomes very low at 523 K and over 1.6% of O2. In the NO/C2H4/N2 system, NO is reduced to N2 with about the same NO conversion as that in the NO/N2 system but without NO2 formation. In the NO/C2H4/O2/N2 system, the oxidation of NO to NO2 is dramatically promoted. At 523 K, with the increase of the energy density, NO conversion increases rapidly first, and then almost stabilizes at 93–91% of NO conversion with 61–55% of NO2 selectivity in the energy density range of 317–550 J L−1. It finally decreases gradually at high energy density. A negligible amount of N2O is formed in the above four systems. Of the four systems studied, NO conversion and NO2 selectivity of the NO/C2H4/O2/N2 system are the highest, and NO/O2/C2H4/N2 system has the lowest electrical energy consumption per NO molecule converted.  相似文献   

20.
K3InF6 is synthesized by a sol-gel route starting from indium and potassium acetates dissolved in isopropanol in the stoichiometry 1:3, with trifluoroacetic acid as fluorinating agent. The crystal structures of the organic precursors were solved by X-ray diffraction methods on single crystals. Three organic compounds were isolated and identified: K2InC10O10H6F9, K3InC12O14H4F18 and K3InC12O12F18. The first one, deficient in potassium in comparison with the initial stoichiometry, is unstable. In its crystal structure, acetate as well as trifluoroacetate anions are coordinated to the indium atom. The two other precursors are obtained, respectively, by quick and slow evaporation of the solution. They correspond to the final organic compounds, which give K3InF6 by decomposition at high temperature. The crystal structure of K3InC12O14H4F18 is characterized by complex anions [In(CF3COO)4(OHx)2](5−2x)− and isolated [CF3COOH2−x](x−1)− molecules with x=2 or 1, surrounded by K+ cations. The crystal structure of K3InC12O12F18 is only constituted by complex anions [In(CF3COO)6]3− and K+ cations. For all these compounds, potassium cations ensure only the electroneutrality of the structure. IR spectra of K2InC10O10H6F9 and K3InC12O12F18 were also performed at room temperature on pulverized crystals.  相似文献   

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