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近年来,聚氧酸盐化学发展迅速,有些聚氧酸盐作为催化剂已经实现了工业化 相似文献
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由于聚氧酸盐在催化、制药和阳离子电极等方面具有潜在的应用价值[1~3], 因此一直是无机化学研究的热点[4~8], 自1993年具有双螺旋结构的化合物[(CH3)2NH2]K4[V10O10(H2O)2(OH)4(PO4)7]*4H2O[9]被合成以来, 更多的关注集中在聚氧酸盐的合成及结构研究中. 相似文献
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在水热条件下通过饱和Keggin结构杂多酸(H3PMo12O40 ·14H2O)降解合成了一种具有四缺位的1∶ 8型的高度对称的杂多钼酸盐,(NH4)3H2·4H2O 1. 利用X-射线单晶衍射、元素分析、IR、XRPD和电化学分析进行了表征.并探讨了在酸性溶液中对H2O2分解的电催化作用.结果表明,化合物1修饰的碳糊电极(1-MCPE)在酸性溶液中的循环伏安图出现了三对可逆的氧化还原峰.1-MCPE在酸性水溶液中对过氧化氢的电化学还原反应具有较高的催化活性. 相似文献
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新型化合物[Ni(en)3]2[Ni(en)2(H2O)2][As6V15O42]·4H2O晶体的水热合成与表征 总被引:1,自引:0,他引:1
金属氧酸盐因其在医药临床、工业催化、功能材料等方面的广泛应用而引起人们的关注[1~6], 其中, 有关钒化学的研究一直很活跃, 钒具有与钼、钨明显不同的结构特性, 钒可以采取VO4, VO5和VO6方式配位, 同时, 钒的价态可以是+3, +4和+5价. 由于钒可采取多种配位方式及多种价态, 与钼酸盐和钨酸盐相比, 钒酸盐更具有结构柔顺性, 同时易形成低价或混合价态物种.在以往的文献中, 有关P-V-O体系多金属氧酸盐的水热合成的研究已有大量的报道[7], 在常规溶液合成中, 人们已对As-V-O体系进行了相对深入的研究, 而有关水热合成的研究报道却很少, 已见报道的砷钒化合物有K6*6H2O[8,9], 4-[10], 6-[11](X=SO2-3, SO2-4, H2O). 为了探究水热条件下As-V-O体系的反应特性, 我们开展了这方面的研究工作, 并取得了突破性进展. 本文采用中温水热技术合成了含有机基团的砷矾超分子化合物2**4H2O, 探讨这类化合物的非线性光学性质、催化性质及其它功能特性将是一个非常有意义的研究领域. 相似文献
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K3[GdⅢ(nta)2(H2O)]·6H2O和(NH4)·[GdⅢ(Cydta)(H2O)2]·5H2O的合成及晶体结构 总被引:3,自引:0,他引:3
GdⅢ的配合物常被用作MRI造影剂[1,2]. GdⅢ的离子半径和电子结构分别为0.107 8 nm和高自旋f 7, 理论预测应与氨基多羧酸类配体形成稳定的九配位配合物[3~5]. 为证实理论预测并在此基础上寻找合适的可用于定向修饰的配体以及为提高GdⅢ配合物的脂溶性使其具有更好的细胞渗透性, 选择四齿配体nta和含有脂环烃的六齿配体Cydta分别合成了GdⅢ的配合物, 并测定了它们的分子结构. 结果显示, GdⅢ与nta形成九配位配合物, GdⅢ与Cydta形成八配位配合物. 相似文献
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钽酸盐光催化材料往往具有较高的光催化活性.近年报道的钽酸盐光催化剂主要采用传统高温固相法制备,该方法不可避免地导致高温烧结,使合成的钽酸盐颗粒较大,比表面积较小,而且该方法具有不可克服的晶体转变、结晶度差、分解、挥发和纯度低等缺点,使制备的光催化剂活性较低.而纳米材料由于粒径小,提高了电子和空穴的扩散速度,大大降低了电子和空穴在材料内的复合几率,从而使光催化材料活性大幅提高.此外,粒径减小也使表面原子迅速增多,减小了光的漫反射,同时也使光吸收不易达到饱和,有利于提高光吸收效率.因此,制备纳米材料是提高半导体光催化剂活性的有效手段.目前,采用湿化学的溶液合成方法能在较低温度下获得粒度小且均匀、计量比准确的光催化剂粉末,但是合成钽酸盐光催化剂的水溶性钽前体即乙醇钽(或氯化钽)价格昂贵,而且对潮湿极端敏感易水解,使产物纯度降低,不适合工业化生产.近年来,尽管有文献报道以Ta2O5为原料利用水热、溶胶-凝胶和共沉淀等方法制备钽酸盐,但其合成条件苛刻,合成步骤复杂,合成周期较长,耗能大,产物产量较低且不均匀,很难实现产物的形貌控制来筛选出适合光催化反应的材料.目前关于纳米钽酸盐光催化材料形貌控制方面的研究鲜有报道,主要是由于Ta2O5极难溶解,很难实现液相合成.因此,纳米钽酸盐光催化材料的可控制备是研究的难点.我们发展了熔盐-水热制备钽酸盐新方法,实现了K1.9Na0.1Ta2O6·2H2O的可控制备.利用熔盐法制备一种可溶性钽酸盐前驱体,再通过水热法在液相进一步反应制得纳米钽酸盐光催化材料K1.9Na0.1Ta2O6·2H2O,通过控制反应条件实现了纳米钽酸盐K1.9Na0.1Ta2O6·2H2O的形貌调控,得到了纳米球、微球、去顶八面体形貌和类似榴莲形貌等不同形貌,而利用其它制备方法很难控制钽酸盐的形貌.另外,研究了制备材料吸附和光催化降解罗丹明B的性能,发现该材料光催化活性与形貌直接相关.表征结果表明,制备样品的X射线衍射(XRD)谱图尖锐,结晶较好,其各衍射峰位置均与K2Ta2O6一致,为纯相烧绿石结构,属于立方晶系,空间群为Fd3m.通过分析合成材料的元素组成及含量,确定K:Na:Ta比例近似为1.9:0.1:2.为了进一步研究属于烧绿石型化合物K1.9Na0.1Ta2O6·2H2O的结构,对不同形貌材料进行了红外光谱测试,所有样品在450–1000 cm–1的谱峰可归属于(K, Na)–O和Ta–O键的振动,3300 cm–1左右为晶体结构中水的羟基伸缩振动峰,1720 cm–1左右是晶体结构中水的弯曲振动峰.可以看出,不同形貌材料的红外谱图吸收带宽度和位置十分相似,只存在小的偏移和变化,进一步表明不同形貌的材料具有相似的晶体结构,与XRD结果一致.差热-热重分析确定了结构中所含结晶水数量近似为2.光催化性能测试结果表明,具有纳米球形貌的材料比表面积较大,因而光催化活性最高. 相似文献
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E. A. Kovalenko M. Yu. Palatkina D. G. Samsonenko V. P. Fedin 《Russian Journal of Coordination Chemistry》2012,38(6):379-385
Complexes [Ca(H2O)2(Dmf@CB[6])(Bdc)] · DMF · 4H2O (I) and [Ca(H2O)3(Dmf@CB[6])]Cl2 · 2H2O (II) are synthesized by the heating (95°C) of a mixture of calcium chloride and cucurbit[6]uril (CB[6]) in a mixture of dimethylformamide (DMF) and water with the addition of terephthalic acid (H2Bdc) in the case of complex I or triethylamine for complex II. The compounds are characterized by X-ray diffraction analysis, IR spectroscopy, and thermogravimetric and elemental analyses. The luminescence spectra are also recorded. According to the X-ray diffraction data, the calcium atom is coordinated by the oxygen atoms of the cucurbit[6]uril molecule, water molecules, and terephthalate anion (for I). The internal cavity of the cavitand is occupied by DMF. 相似文献
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通过水热合成制得了硅钨杂多酸镨化合物[H3DETA]3[H2DETA]2[Pr(S iW11O39)2].2H2O[DETA:二乙烯三胺].晶体结构解析表明:该化合物属于三斜晶系,P1-空间群,a=1.200 0(2)nm,b=2.026 1(4)nm,c=2.239 2(5)nm,α=111.60(3)°,β=92.92(3)°,γ=103.56(3)°;V=4.863 8(17)nm3,Z=2,ρ=4.152 g/cm3,μ=26.519 mm-1,F(000)=5 374.化合物中Pr3+键合两个[S iW11O39]8-构成一个[Pr(S iW11O39)2]13-多阴离子,Pr3+与两个[S iW11O39]8-阴离子的八个氧原子配位构成一个畸变的四方反棱柱.此外,多阴离子[Pr(S iW11O39)2]13-和有机分子还通过氢键形成一个大的空腔. 相似文献
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在水溶液中,以邻菲咯啉、丁二酸与硝酸钴为原料合成了一个新的超分子化合物[Co(Phen)2(H2O)2].(HL).(NO3).3H2O,并经元素分析、IR、X射线单晶衍射分析进行了结构表征.结构分析表明,晶体属三斜晶系,P1-空间群,a=0.968 0(2)nm,b=1.370(3)nm,c=1.394 9(3)nm,α=61.714(3)°,β=71.495(4)°,γ=79.575(4)°,V=1.543 7 nm3,Z=2,ρ=1.481 g/cm3,C28H31CoN5O12,Mr=688.51,F(000)=714 andμ=0.627 mm-1,7 754个独立衍射点中,5 428个可观察点满足I≥2σ(I),R1=0.074 5,wR2=0.210 7.晶体中[Co(Phen)2(H2O)2]2+通过π-π相互作用堆积成二维层状结构,层间通过氢键作用构成三维超分子. 相似文献
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由Er2O3、H4SiMo12O40和nmp合成了分子组成为[Er(nmp)4(H2O)3]H[SiMo12O40]2nmp0.5H2O(nmp=N-甲基吡咯烷酮)的配合物,并通过单晶X-射线衍射测定了晶体结构。结果表明,该化合物属单斜晶系,P21/c空间群,晶胞参数a=17.4601(7),b=18.1906(5),c=22.9096(8)?b=105.2980(10),Z=4,V=7018.5(4)3,Dc=2.504g/cm3,R=0.0460,wR=0.1114,F(000)=5064.配合物中Er3+以七配位的单加冠三棱柱构型配阳离子形式存在,与之配位的是4个N-甲基吡咯烷酮和3个H2O分子,该配阳离子与[SiMo12O40]4-阴离子通过静电作用相结合。 相似文献
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《Journal of Coordination Chemistry》2012,65(20):2221-2241
Three complexes, Na4[DyIII(dtpa)(H2O)]2?·?16H2O, Na[DyIII(edta)(H2O)3]?·?3.25H2O and Na3[DyIII (nta)2(H2O)]?·?5.5H2O, have been synthesized in aqueous solution and characterized by FT–IR, elemental analyses, TG–DTA and single-crystal X-ray diffraction. Na4[DyIII(dtpa)(H2O)]2?·?16H2O crystallizes in the monoclinic system with P21/n space group, a?=?18.158(10)?Å, b?=?14.968(9)?Å, c?=?20.769(12)?Å, β?=?108.552(9)°, V?=?5351(5)?Å3, Z?=?4, M?=?1517.87?g?mol?1, D c?=?1.879?g?cm?3, μ?=?2.914?mm?1, F(000)?=?3032, and its structure is refined to R 1(F)?=?0.0500 for 9384 observed reflections [I?>?2σ(I)]. Na[DyIII(edta)(H2O)3]?·?3.25H2O crystallizes in the orthorhombic system with Fdd2 space group, a?=?19.338(7)?Å, b?=?35.378(13)?Å, c?=?12.137(5)?Å, β?=?90°, V?=?8303(5)?Å3, Z?=?16, M?=?586.31?g?mol?1, D c?=?1.876?g?cm?3, μ?=?3.690?mm?1, F(000)?=?4632, and its structure is refined to R 1(F)?=?0.0307 for 4027 observed reflections [I?>?2σ(I)]. Na3[DyIII(nta)2(H2O)]?·?5.5H2O crystallizes in the orthorhombic system with Pccn space group, a?=?15.964(12)?Å, b?=?19.665(15)?Å, c?=?14.552(11)?Å, β?=?90°, V?=?4568(6)?Å3, Z?=?8, M?=?724.81?g?mol?1, D c?=?2.102?g?cm?3, μ?=?3.422?mm?1, F(000)?=?2848, and its structure is refined to R 1(F)?=?0.0449 for 4033 observed reflections [I?>?2?σ(I)]. The coordination polyhedra are tricapped trigonal prism for Na4[DyIII(dtpa)(H2O)]2?·?16H2O and Na3[DyIII(nta)2(H2O)]?·?5.5H2O, but monocapped square antiprism for Na[DyIII(edta)(H2O)3]?·?3.25H2O. The crystal structures of these three complexes are completely different from one another. The three-dimensional geometries of three polymers are 3-D layer-shaped structure for Na4[DyIII(dtpa)(H2O)]2?·?16H2O, 1-D zigzag type structure for Na[DyIII(edta)(H2O)3]?·?3.25H2O and a 2-D parallelogram for Na3[DyIII(nta)2(H2O)]?·?5.5H2O. According to thermal analyses, the collapsing temperatures are 356°C for Na4[DyIII(dtpa)(H2O)]2?·?16H2O, 371°C for Na[DyIII(edta)(H2O)3]?·?3.25H2O and 387°C for Na3[DyIII(nta)2(H2O)]?·?5.5H2O, which indicates that their crystal structures are very stable. 相似文献
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S. V. Larionov L. I. Myachina L. A. Glinskaya I. V. Korol’kov E. M. Uskov O. V. Antonova V. M. Karpov V. E. Platonov V. P. Fadeeva 《Russian Journal of Coordination Chemistry》2012,38(12):717-723
Compounds p-HOOCC6F4COOH · H2O (H2L · H2O), [Tb2(H2O)4(L)3 · 2H2O] n (I), and Tb2(Phen)2(L)3 · 2H2O (II) are synthesized. According to the X-ray structure analysis data, the crystal structure of H2L · H2O is built of centrosymmetric molecules H2L and molecules of water of crystallization. The crystal structure of compound I is built of layers of coordination 2D polymer [Tb2(H2O)4(L)3] n and molecules of water of crystallization. The ligands are the L2? anions performing both the tetradentate bridging and pentadentate bridging-chelating functions. The coordination polyhedron TbO9 is a distorted three-capped trigonal prism. Acid H2L manifests photoluminescence in the UV region (??max = 368 nm). Compounds I and II have the green luminescence characteristic of the Tb3+ ions, and the band with ??max = 545 nm (transition 5 D 4?? 7 F 5) is maximum in intensity. The photoluminescence intensity of compound II is higher than that for compound I. 相似文献
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The crystal and molecular structures of K3[TbIII(nta)2(H2O)](5.5H2O (nta = nitrilotriacetic acid) and K3[YbIII(nta)2](5H2O complexes have been determined by single-crystal Xray structural analyses. Because TbIII and YbIII have different ionic radii and electronic configura- tions, they take nine- and eight-coordinate structures with two nta ligands, respectively. The crystal of K3[TbIII(nta)2(H2O)](5.5H2O belongs to orthorhombic, space group Pccn with a = 1.6374(7), b = 1.9913(8), c = 1.5068(6) nm, V = 4.913(3) nm3, Z = 8, Mr = 769.54, Dc = 2.081 g/cm3, μ= 3.476 mm-1 and F(000) = 3048. The final R and wR are 0.0432 and 0.0916 for 4961 observed reflections (I > 2.0(σI)), and 0.0814 and 0.1042 for all 21921 reflections, respectively. The [TbIII(nta)2(H2O)]3- complex anion has a nine-coordinate pseudo-monocapped square anti-prismatic structure, in which two N and six O coordinated atoms are from two nta ligands and the left ninth O atom from one water molecule. The crystal of K3[YbIII(nta)2]·5H2O is of monoclinic, space group P21/c with a = 1.5579(5), b = 0.9981(3), c = 1.5956(5) nm, β = 109.776(5), V = 2.3348(13) nm3, Z = 4, Mr = 756.62, Dc = 2.153 g/cm3, μ= 4.624 mm-1 and F(000) = 1484. The final R and wR are 0.0253 and 0.0657 for 4123 observed reflections (I > 2.0(σI)), and 0.0320 and 0.0731 for all 9414 reflections, respectively. The [YbIII(nta)2]3- complex anion has an eight-coordination structure with a distorted square antiprismatic prism, in which each nta acts as a tetradentate ligand with one N atom from the amino group and three O atoms from the carboxylic groups. 相似文献
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研究了多金属氧酸盐分子基化合物K3[Cr3O(OOCH)6(H2O)3][α-GeW12O40]·17H2O的合成、晶体结构及其结晶水可逆脱附和吸附性能.该化合物属于单斜晶系,C2/m空间群,α=2.738
3(6)nm,b=1.58 3 0(3)nm,c=1.730 4(4)nm,β=102.43(3)°,V=7.325(3)nm3,Z=4,R1(wR2)=0.067
8(0.171 9).该晶体具有孔道结构,孔道内的结晶水能够可逆的脱附和吸附,而晶体结构随之恢复,因此具有分子筛的特性. 相似文献