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1.
配合物[Ru(bpy)2(H2biim)](PF6)2(1)(bpy=2,2′-联吡啶,H2biim=2,2′-联咪唑)和[Ru(bpy)2(H2bbim)](PF6)2(4)(H2bbim=2,2′-苯并联咪唑)是良好的阴离子识别剂.用密度泛函理论方法研究了2种阴离子识别剂脱去质子后的几何结构和电子结构的变化.计算结果表明:脱去质子后配合物HOMO轨道上电子云分布由中心钌原子转移到(苯并)联咪唑上,而LUMO轨道虽然能量增加但电子云仍然分布在bpy配体上;另外,最高占居轨道HOMO与最低空轨道LUMO的能量差ΔεL-H逐渐减小,相对于配合物的吸收波长增大,所以分子的吸收峰发生红移,这与实验现象相吻合。  相似文献   

2.
以3-硝基邻苯二甲酸和咪唑及2,2′-联吡啶为配体构筑了2种配合物[Zn2(npa)2(Im)4](1)和[Cd2(npa)2(2,2′-bipy)2(H2O)2]·2H2O(2)(npa2-=3-硝基邻苯二甲酸根,Im=咪唑,2,2′-bipy=2,2′-联吡啶)。用元素分析、红外光谱对其进行了表征,并用单晶X-射线衍射测定了配合物的晶体结构;测定了配合物1和2的热稳定性。2个配合物均为双核分子,具有M2C8O4十四元大环结构。配合物1的双核单元通过分子间氢键形成3D网络结构,配合物2的双核单元通过分子间氢键和π-π堆积形成2D层状结构。  相似文献   

3.
以多联吡啶类配体取代咪唑3-位,合成了2个配体,进而得到了2个钌配合物[Ru(tpy-PhCH2-Im-Naph)2](PF64C1)和[Ru(2,2’-bpy)2(2,2’-bpy-(CH2-Im-CH32)](PF64C2)(tpy=2,2’:6’,2″-三联吡啶,bpy=2,2’-联吡啶,Im=咪唑,Naph=5,7-二甲基-1,8-萘啶),通过核磁、质谱、元素分析,紫外、荧光等对这些化合物进行了表征,经X-射线晶体衍射分析确定了配合物C1的晶体结构。结构解析表明:配合物C1是离子型化合物,沿c轴方向堆积成规律的孔洞状。电化学性质测试揭示了氧化还原是一个单电子可逆的过程,对应的可逆对为Ru(Ⅲ)/Ru(Ⅱ),E1/2分别为1.26和1.32V。C1C2与CO2的加合物的红外光谱测试表明,这些化合物在碱的作用下能形成碳卡宾,可与CO2结合。  相似文献   

4.
合成了3个钌髤配合物,[Ru(bpy)2(SB)](PF6)2、[Ru(bpy)(SB)2](PF6)2和[Ru(SB)3](PF6)2(bpy=2,2′-bipyridine,SB=4,5-diaza-9,9′-spirobifluorene),通过核磁和元素分析对配合物的结构进行了确定。[Ru(bpy)2(SB)](PF6)2通过X射线单晶衍射确认了结构。研究了配合物的光物理性能。结果表明[Ru(bpy)2(SB)](PF6)2在乙腈中的发桔红光,波长为606 nm,量子产率约为0.001 2。在同样条件下[Ru(bpy)(SB)2](PF6)2和[Ru(SB)3](PF6)2的发光非常微弱甚至几乎没有发光。还研究了这些配合物的电致化学发光性能。随着配体中SB含量的增加,发光的峰电压从1.36 V增加到1.58 V,相对发光强度从731降低到52。  相似文献   

5.
利用水热方法合成了一个三联吡啶钌磺基苯甲酸配合物,[Ru(2,2′-bipy)3](3-Hsb)(3-sb).5H2O(1)(2,2′-bipy为2,2′-联吡啶;3-sb2-为3-磺基苯甲酸根离子),对配合物进行了元素分析、红外、紫外、荧光和差热热重表征,解析了配合物的晶体结构。晶体结构解析表明:配合物1是阴离子-阳离子型化合物,阴离子与水分子形成三维有孔洞的氢键网络,阳离子占据这些孔洞。电化学性质测试表明:氧化还原是一个单电子可逆的过程,对应的可逆对为Ru(Ⅳ)/Ru(Ⅲ),E1/2=1.350 V。室温苯甲硫醚氧化催化实验表明:钌配合物与酸结合具有较高的催化活性与亚砜选择性。  相似文献   

6.
邓洪  李红  徐宏  计亮年 《化学学报》2002,60(12):2159-2166
合成了4-氰基苯基咪唑并[5,6-f]邻菲咯啉(CYIP)和2-羧基苯基咪唑并[5, 6-f]邻菲咯啉(COIP)两种新配体及它们的钌混配配合物[Ru(bpy)2CYIP](ClO4)2 ·H2O(Rul)(bpy=2,2′-联吡啶),[Ru(phen)2CYIP](ClO4)2·H2O(Ru2) (phen=1,10-邻菲咯啉),[Ru(bpy)2COIP](ClO4)2·3H2O(Ru3)和[Ru(phen)2COIP] (ClO4)2·H2O(Ru4),并用红外光谱、紫外光谱、核磁和质谱对它们进行了表征。 通过循环伏安法研究了这些配合物的电化学性质。采用电子吸收光谱、稳态荧光、 圆二色谱和粘度测定研究了配合物与小牛胸腺DNA的相互作用。结果表明配合物 Rul和Ru2通过CYIP配体以插入的方式与DNA结合,而配合物Ru3和Ru4则通过COIP配 体以部分插入的方式与DNA结合。  相似文献   

7.
使用2,2′-二硫代二苯甲酸和2,2′-联吡啶(2,2′-bipy)、硝酸铜在水热条件下发生的原位反应合成了一个铜配合物,即[Cu2(C14H8O4S)2(C10H8N2)2](1)(C14H8O4S=2,2′-二羧苯基硫醚,C10H8N2=2,2′-联吡啶);然后又利用2,2′-二硫代二苯甲酸和菲咯啉(phen)、氯化钙在水溶液中合成了一个钙配合物,即{[Ca(C14H8O4S2)(C12H8N2)2]·(H2O)2}n(2)(C14H8O4S=2,2′-二硫代二苯甲酸根,C12H8N2=菲咯啉),并对它们分别进行了元素分析、红外光谱、热稳定性、X射线粉末衍射和X射线单晶衍射的表征。结果表明:配合物1由2,2′-二羧苯基硫醚配体连接形成了一个双核的化合物,通过氢键和氮杂环之间的π…π作用形成三维超分子网络结构。配合物2由二硫代二苯甲酸配体桥联形成了一个一维链状结构,通过氢键和氮杂环之间的π…π作用也形成三维超分子网络结构。并且,对这2个配合物的热稳定性分别进行了研究。  相似文献   

8.
李襄宏 《无机化学学报》2010,26(8):1389-1393
合成了2个新的含1,3,4-噁二唑官能团的联吡啶配体及其相应的钌髤配合物Ru(CPOD)(dcbpy)(NCS)2(Ru-1)和Ru(DPOD)(dcbpy)(NCS)2(Ru-2)(CPOD=4-羧基-4′-[2-(4-壬氧基苯基)-5-苯基-1,3,4-噁二唑]-2,2′-二联吡啶,DPOD=4,4′-二[2-(4-壬氧基苯基)-5-苯基-1,3,4-噁二唑]-2,2′-二联吡啶,dcbpy=4,4′-二羧基-2,2′-二联吡啶),并通过红外光谱、循环伏安、紫外可见吸收光谱、元素分析和光电流-光电压曲线实验对其结构和光电转化性质进行了表征。这些配合物的最大MLCT态吸收位于555nm,摩尔消光系数可达1.43×104L·mol-1·cm-1。它们的光化学和电化学性质表明:激发态能级与TiO2导带底能级匹配,电子能够注入到TiO2导带中。将它们敏化到纳米晶TiO2电极上,光电转化效率为2.4%。  相似文献   

9.
利用紫外-可见吸收光谱、荧光光谱、圆二色谱等光谱手段,以及黏度测定等流体力学方法在三羟甲基氨基甲烷(tris)缓冲溶液和磷酸缓冲溶液中研究了含季铵盐联吡啶配体的钌(Ⅱ)配合物[Ru(L)(phen)2](PF6)4(L=5,5′-二(三甲铵基甲基)-2,2′-联吡啶离子,phen=邻菲咯啉)与小牛胸腺DNA(CT-DNA)的相互作用.结果表明,合成的配合物与CT-DNA之间存在一定的亲和作用,拟合得到的结合常数可达105;与此同时,该配合物能够稳定CT-DNA的结构,并对CT-DNA有较好的立体选择性(右旋异构体优先与DNA结合).  相似文献   

10.
合成了一组钌多吡啶化合物[Ru(bpy))2(DMBbimH_x)]~(y+)(bpy=2,2′-联吡啶,DMBbimH2=7,7′-二甲基-2,2′-苯并联咪唑,1-A:x=2;y=2;1-B:x=1,y=1;1-C:x=0,y=0)并测试了它们的核磁氢谱、紫外吸收和电化学性质。随着DMBbimHx配体逐个脱去质子,配合物的光谱和电化学性质发生明显的变化。有趣的是,脱去一个质子的配合物1-B在不同极性的二氯甲烷和乙腈中的电化学性质呈现明显的差异:在二氯甲烷中,单核的1-B却能发生两步氧化,这是因为在弱极性的溶剂中,[Ru(bpy)_2(DMBbimH)]+阳离子通过氢键结合形成二聚体,[Ru(bpy)_2(DMBbimH)]+阳离子间存在质子耦合电子传递现象。在1-B的二氯甲烷溶液中得到了化合物[Ru(bpy)_2(DMBbimH)]PF_6·2CH2Cl_2(2)的单晶。晶体结构分析表明[Ru(bpy)_2(DMBbimH)]+阳离子确实通过氢键结合形成二聚体,这与电化学测试的结果一致。而在极性较大的乙腈中,氢键二聚体不能稳定存在,在循环伏安曲线上只有一个峰存在。  相似文献   

11.
娄太平  张乐  郭军兴 《化学学报》2010,68(6):466-470
研究了在不同温度下的NaNO3和AgNO3水溶液中Li1.3Ti1.7Al0.3(PO4)3和Na1.3Ti1.7Al0.3(PO4)3离子交换行为.实验表明Li1.3Ti1.7Al0.3(PO4)3和Na1.3Ti1.7Al0.3(PO4)3均显示出了高选择性与Na+和Ag+进行离子交换的特征,且对Ag+的选择性高于Na+.升高温度可显著提高Ag/Li和Ag/Na的交换反应速度.  相似文献   

12.
Single crystals of K3RESi2O7 (RE=Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) were grown from a potassium fluoride flux. Two different structure types were found for this series. Silicates containing the larger rare earths, RE=Gd, Tb, Dy, Ho, Er, Tm, Yb crystallize in a structure K3RESi2O7 that contains the rare-earth cation in both a slightly distorted octahedral and an ideal trigonal prismatic coordination environment, while in K3LuSi2O7, containing the smallest of the rare earths, lutetium is found solely in an octahedral coordination environment. The structure of K3LuSi2O7 crystallizes in space group P63/mmc with a=5.71160(10) Å and c=13.8883(6) Å. The structures containing the remaining rare earths crystallize in the space group P63/mcm with the lattice parameters of a=9.9359(2) Å, c=14.4295(4) Å, (K3GdSi2O7); a=9.88730(10) Å, c=14.3856(3) Å, (K3TbSi2O7); a=9.8673(2) Å, c=14.3572(4) Å, (K3DySi2O7); a=9.8408(3) Å, c=14.3206(6) Å, (K3HoSi2O7); a=9.82120(10) Å, c=14.2986(2) Å, (K3ErSi2O7); a=9.80200(10) Å, c=14.2863(4) Å, (K3TmSi2O7); a=9.78190(10) Å, c=14.2401(3) Å, (K3YbSi2O7). The optical properties of the silicates were investigated and K3TbSi2O7 was found to fluoresce in the visible.  相似文献   

13.
The near infrared spectra of aqueous solutions of the ethylsulfates of La, Nd, Gd, Tb, Er, Yb, Lu, Y, and Na have been determined from about 0.2 mol-dm–3 to nearly saturation. The extinction coefficients of water have been calculated taking into account the absorption of ethylslfate anions determined in separate experiments. Their values appeared to be nearly the same as that of pure water. The relative contents of free OH groups in 0.5 and 0.7M solutions have been estimated from the absorbances at 1160 nm. They were lower in solutions of the heavy rare-earth ethylsulfates (Tb, Er, Yb, Lu) than in equimolar solutions of the lighter ones (La, Nd), confirming our previous view that secondary hydration of the heavy trivalent rare-earth cations is distinctly stronger than that of the lighter ones. A comparison of the spectra of these aqueous ethylsulfates with those of perchlorates shows that the structure-breaking ability of the C2H5SO 4 ion is much smaller than that of perchlorate anion.  相似文献   

14.
The crystal structures of compounds with nominal compositions Bi6FeP2O15+x (I), Bi6NiP2O15+x (II) and Bi6ZnP2O15+x (III) were determined from single-crystal X-ray diffraction data. They are monoclinic, space group I2, Z=2. The lattice parameters for (I) are a=11.2644(7), b=5.4380(3), c=11.1440(5) Å, β=96.154(4)°; for (II) a=11.259(7), b=5.461(4), c=11.109(7) Å, β=96.65(1)°; for (III) a=19.7271(5), b=5.4376(2), c=16.9730(6) Å, β=131.932(1)°. Least squares refinements on F2 converged for (I) to R1=0.0554, wR2=0.1408; for (II) R1=0.0647, wR2=0.1697; for (III) R1=0.0385, wR2=0.1023. The crystals are complexly twinned by 2-fold rotation about , by inversion and by mirror reflection. The structures consist of edge-sharing articulations of OBi4 tetrahedra forming layers in the a-c plane that then continue by edge-sharing parallel to the b-axis. The three-dimensional networks are bridged by Fe and Ni octahedra in (I) and (II) and by Zn trigonal bipyramids in (III) as well as by oxygen atoms of the PO4 moieties. Bi also randomly occupies the octahedral sites. Oxygen vacancies exist in the structures of the three compounds due to required charge balances and they occur in the octahedral coordination polyhedron of the transition metal. In compound (III), no positional disorder in atomic sites is present. The Bi-O coordination polyhedra are trigonal prisms with one, two or three faces capped. Magnetic susceptibility data for compound (I) were obtained between 4.2 and 350 K. Between 4.2 and 250 K it is paramagnetic, μeff=6.1 μB; a magnetic transition occurs above 250 K.  相似文献   

15.
The room temperature structures of the five layer Aurivillius phases A2Bi4Ti5O18 (A=Ca, Sr, Ba and Pb) have been refined from powder neutron diffraction data using the Rietveld method. The structures consist of [Bi2O2]2+ layers interleaved with perovskite-like [A2Bi2Ti5O16]2− blocks. The structures were refined in the orthorhombic space group B2eb (SG. No. 41), Z=4, and the unit cell parameters of the oxides are a=5.4251(2), b=5.4034(1), c=48.486(1); a=5.4650(2), b=5.4625(3), c=48.852(1); a=5.4988(3), b=5.4980(4), c=50.352(1); a=5.4701(2), b=5.4577(2), c=49.643(1) for A=Ca, Sr, Ba and Pb, respectively. The structural features of the compounds were found similar to n=2-4 layers bismuth oxides. The strain caused by mismatch of cell parameter requirements for the [Bi2O2]2+ layers and perovskite-like [A2Bi2Ti5O16]2− blocks were relieved by tilting of the TiO6 octahedra. Variable temperature synchrotron X-ray studies for Ca and Pb compounds showed that the orthorhombic structure persisted up to 675 and 475 K, respectively. Raman spectra of the compounds are also presented.  相似文献   

16.
针对银精矿样品复杂,难消解的特点,研究了不同酸溶法和碱熔法对样品的消解情况,建立了硝酸,盐酸,氢氟酸,高氯酸消解银精矿的方法。根据元素灵敏度和抗干扰性,选定各元素的测定波长。通过酸溶样和碱熔样测定结果比对,验证了方法准确性。建立了四酸消解-电感耦合等离子体光谱法测定银精矿中铜、铅、锌、砷、镉、钙、镁、锰含量的方法,元素的线性相关系数均在0.9999以上。通过共存元素干扰实验,确定了银精矿中高含量元素(铜、铅、锌、铁、锑、铋等)对测定元素结果没有影响。方法检出限:Cu 0.0063 mg/L, Pb 0.0159 mg/L ,Zn 0.0090 mg/L,As 0.0192 mg/L, Cd 0.0093 mg/L ,Ca 0.0084 mg/L, Mg 0.0075 mg/L, Mn 0.0081 mg/L。测定下限:Cu 0.0105mg/L,Pb 0.0265 mg/L, Zn 0.0150 mg/L, As 0.0320 mg/L, Cd 0.0155 mg/L, Ca 0.0140 mg/L, Mg 0.0125 mg/L,Mn 0.0135 mg/L。3个样品的相对标准偏差在0.87%~3.56%之间,加标回收率在95.00%~103.56%之间。方法流程短,操作简单,快速,灵敏度和再现性高,结果准确可靠,可以满足银精矿中铜、铅、锌、砷、镉、钙、镁、锰含量的测定。  相似文献   

17.
通过调节B2O3-Bi2O3-ZnO-Al2O3(BBZA)玻璃的添加量研究其对钛酸钡(BaTiO3)陶瓷烧结条件、晶体结构和介电性能的影响。结果表明:添加适量的BBZA玻璃能够有效地将BaTiO3陶瓷烧结温度由1 350℃降至950℃,并使其致密化。同时,添加BBZA玻璃后,BaTiO3的晶体结构随着烧结温度的升高而发生转变(立方相→四方相)。另外,BBZA玻璃的引入使BaTiO3陶瓷的居里峰得到了有效的抑制和拓宽。陶瓷微观形貌显示,玻璃相均匀分布在BaTiO3晶粒表面。优化的BaTiO3陶瓷制备条件如下:BBZA添加量(质量分数)为2.0%,烧结温度为950℃。在该条件下制备的BaTiO3陶瓷介电常数达到1 364,介电损耗低至1.2%。  相似文献   

18.
Tao Lin  Wei Li  Maochu Gong  Yao Yu  Bo Du  Yaoqiang Chen   《Acta Physico》2007,23(12):1851-1856
TiO2,ZrO2-TiO2,andZrO2-TiO2-CeO2 were prepared by co-precipitation method and characterized by X-ray diffraction (XRD), specific surface area measurements (BET), temperature programmed desorption (NH3-TPD), oxygen storage capacity (OSC), and temperature programmed reduction (H2-TPR). The results showed that ZrO2-TiO2-CeO2 exhibited large number of surface strong acid, possessed some oxygen storage capacity, and strong redox property. The three materials were used as supports and the monolith catalysts were prepared with 1% (w) V2O5 and 9% (w)WO3 for selective catalytic reduction (SCR) of NO with ammonia in the presence of excessive O2, and the results of catalytic activity showed that the catalyst used ZrO2-TiO2-CeO2 as support yielded nearly 100% NO conversion at 275 °C at a gas hourly space velocity (GHSV) of 10000 h−1, and it had the best catalytic activity and showed great potential for practical application.  相似文献   

19.
The phase relations in the system In2O3–TiO2–MgO at 1100 and 1350°C are determined by a classical quenching method. In this system, there are four pseudobinary compounds, In2TiO5, MgTi2O5 (pseudobrookite type), MgTiO3 (ilmenite type), and Mg2TiO4 (spinel type) at 1100°C. At 1350°C, in addition to these compounds there exist a spinel-type solid solution Mg2−xIn2xTi1−xO4 (0≤x≤1) and a compound In6Ti6MgO22 with lattice constants a=5.9236(7) Å, b=3.3862(4) Å, c=6.3609(7) Å, β=108.15(1)°, and q=0.369, which is isostructural with the monoclinic In3Ti2FeO10 in the system In2O3–TiO2–MgO. The relation between the lattice constants of the spinel phase and the composition nearly satisfies Vegard's law. In6Ti6MgO22 extends a solid solution range to In20Ti17Mg3O67 with lattice constants of a=5.9230(5) Å, b=3.3823(3) Å, c=6.3698(6) Å, β=108.10(5)°, and q=0.360. The distributions of constituent cations in the solid solutions are discussed in terms of their ionic radius and site preference effect.  相似文献   

20.
The crystal structures of Bi2.5Na0.5Ta2O9 and Bi2.5Nam-1.5NbmO3m+3 (m=3,4) have been investigated by the Rietveld analysis of their neutron powder diffraction patterns (λ=1.470 Å). These compounds belong to the Aurivillius phase family and are built up by (Bi2O2)2+ fluorite layers and (Am-1BmO3m+1)2- (m=2-4) pseudo-perovskite slabs. Bi2.5Na0.5Ta2O9 (m=2) and Bi2.5Na2.5Nb4O15 (m=4) crystallize in the orthorhombic space group A21am, Z=4, with lattice constants of a=5.4763(4), b=5.4478(4), c=24.9710 (15) and a=5.5095(5), b=5.4783(5), c=40.553(3) Å, respectively. Bi2.5Na1.5Nb3O12 (m=3) has been refined in the orthorhombic space group B2cb, Z=4, with the unit-cell parameters a=5.5024(7), b=5.4622(7), and c=32.735(4) Å. In comparison with its isostructural Nb analogue, the structure of Bi2.5Na0.5Ta2O9 is less distorted and bond valence sum calculations indicate that the Ta-O bonds are somewhat stronger than the Nb-O bonds. The cell parameters a and b increase with increasing m for the compounds Bi2.5Nam-1.5NbmO3m+3 (m=2-4), causing a greater strain in the structure. Electron microscopy studies verify that the intergrowth of mixed perovskite layers, caused by stacking faults, also increases with increasing m.  相似文献   

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