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1.
配位聚合物通常是通过某种有机配体与金属的配位几何选择以及无限网络的拓扑结构控制而形成的具有无限结构的化合物 [1] ,其结构新颖并具有不寻常的光电效应、非线性光学性能、磁性、超导及催化等诸多具有诱人应用前景的独特性能 .因此 ,近年来倍受化学家和材料学家的重视 [2~ 5] .以 Co为配位中心的配位聚合物若具有八面体构型 ,在一定条件下具有自旋转换能力 ,而且往往可与光电转换能力相关联 ,是一种潜在的新型信息存储材料 [6 ] .对于配位聚合物的形成 ,配体的选择最重要 . 4,4′-联吡啶及其衍生物是一种较好的刚性配体 ,相关的配位聚…  相似文献   

2.
稀土离子具有独特的电子结构和成键特征,配位数高且多变,因而稀土配合物能表现出独特的光、电、磁性质。目前,设计和合成含有稀土离子的功能配合物作为发光分子器件和荧光探针是配位化学和超分子化学等研究领域的热点课题[1 ̄6]。研究表明,稀土配合物的发光性能和稳定性可通过改变其配体的组成和结构加以调控。因此,设计、合成具有新颖结构、良好配位能力及高效能量吸收和传递性能的有机配体是研究和开发新型稀土配合物发光材料的关键课题之一。多足配体在与金属离子配位时,能够表现出特有的选择性配位能力、类球形配位空穴和新颖的配位结构…  相似文献   

3.
近年来,金属有机配位聚合物由于其独特的电学、磁学、催化和光学性能而受 到普遍关注。通过选择不同的多齿配体和金属离子,可以组装成具有各处新型骨架 结构和特殊物理化学性能的配位聚合物。异烟酸根可以通过吡啶环氮原子和羧基氧 原子与金属离子配位,生成配位聚合物。本文采用三氯化铁和4-氰基吡啶在水热条 件下的反应可控地合成具有三维骨架结构的配位聚合物[Fe(C_5H_4NCOO)_2]_n,并 进行元素分析、红外光谱表征,单晶结构测定和UV-VIS-NIR(紫外-可见-近红外) 反射光谱研究。  相似文献   

4.
近年来,取代在5位上的间苯二甲酸(取代基为:-SO3H,-NH2,-OH,-NO2等)衍生物与过渡金属形成的配位聚合物,由于其具有新奇的结构,而且是潜在的功能材料而备受关注[1 ̄4]。Yaghi等人认为,取代基对配位聚合物的结构和性能具有重要的修饰作用[5]。因此我们在研究5-硝基间苯二甲酸、5-羟基间苯二甲酸与过渡金属形成的配位聚合物结构的同时[6,7],选择了5-氨基间苯二甲酸作为酸性配体,氨基不仅能用其氮原子与金属配位,还能形成氢键,能够提供丰富的配位方式。我们曾经报道了{[Co(4,4′-bipy)(hmbdc)(H2O)2](4,4′-bipy)(DMF)}n的合成与结构[8…  相似文献   

5.
0引言由于羧酸化合物具有丰富的配位结构类型,而且羧酸桥联多核配合物广泛存在于生物体内金属蛋白和金属酶的活性部位,使其在配位化学中占有重要地位[1]。尤其是近年来,研究发现羧酸配位聚合物具有潜在的光学、磁学、吸附分离、信息储存以及催化等性能,使得由苯二甲酸,均苯三甲  相似文献   

6.
两个二维Cd(Ⅱ)配位聚合物的合成、晶体结构和荧光性质   总被引:7,自引:0,他引:7  
具有d^10电子结构的简单金属配合物是不发光的。然而,采用具有π共轭芳香类有机物为配体所构建的Zn(Ⅱ)和Cd(Ⅱ)配合物,特别是具有重复单元结构的配位超分子和配位聚合物,能够发射较强的荧光,由于它们的配位数和结构的多样性,如[Cd4(betc)2(phen)2(H2O)]n(bete=1,2,4,5-benzenetetracarboxyl),[Cd(isonicotinate)2(EtOH)](EtOH),使这类化合物往往显示出一些新奇的功能。本文分别采用均苯四甲酸根和烟酸根为桥配体,合成了两种具有二维无限结构的Cd(Ⅱ)配位聚合物,它们在紫外光照射下,可以发出较强的蓝色荧光。  相似文献   

7.
镍是生物中必要的痕量元素,能促进体内铁的吸收、红细胞的增长、氨基酶的合成,镍可能是DNA和RNA的一种结构稳定剂[2].大多数席夫碱化合物具有抗肿瘤、抗菌等生物活性,而腙类化合物因具有优良的生物活性、强配位能力和多样的配位形式,在农药、医药及分析等方面的应用受到广泛的关注[3~9].我们实验室长期以来从事席夫碱及其金属配合物的合成和生物活性研究,我们曾报道过水杨酰腙Schiff碱配体与Cu(Ⅱ)配合的结构和生物活性[10],为了进一步研究镍配合物的配位构型及其性能,本文报道了标题化合物镍的四配位结构.  相似文献   

8.
由有机配体同金属离子作用构建的配位聚合物具有与无机微孔晶体类似的空旷骨架结构,并在非线性光学材料、磁性材料、超导材料及催化等诸多方面具有潜在的应用前景[1~4].在配位聚合物的合成中,配体的种类不仅直接影响到聚合物的合成,而且还涉及到聚合物的结构维数[5~7].目前,用来构建这些配合物的有机配体大多数都带有相同的可配位基团,较少应用具有两种以上的配位基团的有机配体.本文采用同时含有氮和氧两种配位原子的多齿配体氨基三乙酸[8~12],在水热条件下分别以Co2+和Ni2+作为组装基元,通过自组装合成了具有三维骨架结构的Na[M(nta)]·H2O [M=Co(1),Ni(2)]配位聚合物,并进行了结构与磁性研究.  相似文献   

9.
羧酸可以采取螯合双齿,桥式双齿,μ3-桥式和单齿等多种形式与稀土离子配位,相应的配合物往往具有层状、无限链状和网层状聚合等特殊结构。羧酸稀土配合物在发光材料、催化和磁性材料等方面均有应用因而受到广泛关注[1-5]。其中芳香羧酸与稀土离子的配合物由于具有优异的发光性能和热稳定性一直是人们研究的热点[6-10]。文献[6-9]对稀土.  相似文献   

10.
张向东  葛春华  尹晶  赵阳  何翠 《中国化学》2009,27(6):1195-1198
在常规条件下,合成了具有新颖结构的配位聚合物[Mn(bdpbp)2(NO3)2]n (1) [bdpbp =4,4’-二(磷酸二甲酯甲基)联苯]。配合物1由单晶x-射线衍射确定结构,并用元素分析、红外光谱、荧光光谱和热重进行了表征和性质研究。配合物1具有二维无限的网格状结构,形成双重互穿,并由弱的C-H···O氢键进一步连接成三维超分子网络。  相似文献   

11.
The reaction of (R(2)PCH(2)SiMe(2))(2)NM (PNP(R)M; R = Cy; M = Li, Na, MgHal, Ag) with L(2)ReOX(3) [L(2) = (Ph(3)P)(2) or (Ph(3)PO)(Me(2)S); X = Cl, Br] gives (PNP(Cy))ReOX(2) as two isomers, mer,trans and mer,cis. These compounds undergo a double Si migration from N to O at 90 degrees C to form (POP(Cy))ReNX(2) as a mixture of mer,trans and fac,cis isomers. Additional thermolysis effects migration of CH(3) from Si to Re, along with compensating migration of halide from Re to Si. DFT calculations on various structural isomers support the greater thermodynamic stability of the POP/ReN isomer vs PNP/ReO and highlight the influence of the template effect on the reactivities of these species.  相似文献   

12.
A zero-valent [M(Ph(2)PCH(2)CH(2)PPh(2))(2)] moiety (M = Mo, W) generated in situ by dissociation of the N(2) ligands in trans-[M(N(2))(2)(Ph(2)PCH(2)CH(2)PPh(2))(2)] can activate pi-accepting organic molecules including isocyanides and nitriles, which undergo the electrophilic attack caused by a strong pi-donation from a zero-valent metal center. Cleavage of a variety of C-X bonds (X = H, C, N, O, P, halogen) also occurs at their electron-rich sites through oxidative addition to form reactive intermediates, which subsequently degradate to yield smaller molecules either bound to or dissociated from the metal center. The mechanism is substantiated unambiguously by isolation of numerous intermediate stages.  相似文献   

13.
14.
The nucleophilicity of the [Pt(2)S(2)] core in [[Ph(2)P(CH(2))(n)PPh(2)]Pt(mu-S)(2)Pt[Ph(2)P(CH(2))(n)PPh(2)]] (n = 3, dppp (1); n = 2, dppe (2)) metalloligands toward the CH(2)Cl(2) solvent has been thoroughly studied. Complex 1, which has been obtained and characterized by X-ray diffraction, is structurally related to 2 and consists of dinuclear molecules with a hinged [Pt(2)S(2)] central ring. The reaction of 1 and 2 with CH(2)Cl(2) has been followed by means of (31)P, (1)H, and (13)C NMR, electrospray ionization mass spectrometry, and X-ray data. Although both reactions proceed at different rates, the first steps are common and lead to a mixture of the corresponding mononuclear complexes [Pt[Ph(2)P(CH(2))(n)PPh(2)](S(2)CH(2))], n = 3 (7), 2 (8), and [Pt[Ph(2)P(CH(2))(n)PPh(2)]Cl(2)], n = 3 (9), 2 (10). Theoretical calculations give support to the proposed pathway for the disintegration process of the [Pt(2)S(2)] ring. Only in the case of 1, the reaction proceeds further yielding [Pt(2)(dppp)(2)[mu-(SCH(2)SCH(2)S)-S,S']]Cl(2) (11). To confirm the sequence of the reactions leading from 1 and 2 to the final products 9 and 11 or 8 and 10, respectively, complexes 7, 8, and 11 have been synthesized and structurally characterized. Additional experiments have allowed elucidation of the reaction mechanism involved from 7 to 11, and thus, the origin of the CH(2) groups that participate in the expansion of the (SCH(2)S)(2-) ligand in 7 to afford the bridging (SCH(2)SCH(2)S)(2-) ligand in 11 has been established. The X-ray structure of 11 is totally unprecedented and consists of a hinged [(dppp)Pt(mu-S)(2)Pt(dppp)] core capped by a CH(2)SCH(2) fragment.  相似文献   

15.
1 INTRODUCTION The picolinic acid (picH), also called pyridine- 2-carboxylic acid, has a broad spectrum of physio- logical effects on the activity functions of both ani- mal and plant organisms. It is attributed increasing interest due to its ability to …  相似文献   

16.
Huang FQ  Ibers JA 《Inorganic chemistry》2001,40(11):2602-2607
The new compounds K(2)TiCu(2)S(4), Rb(2)TiCu(2)S(4), Rb(2)TiAg(2)S(4), Cs(2)TiAg(2)S(4), and Cs(2)TiCu(2)Se(4) have been synthesized by the reactions of A(2)Q(3) (A = K, Rb, Cs; Q = S, Se) with Ti, M (M = Cu or Ag), and Q at 823 K. The compounds Rb(2)TiCu(2)S(4), Cs(2)TiAg(2)S(4), and Cs(2)TiCu(2)Se(4) are isostructural. They crystallize with two formula units in space group P4(2)/mcm of the tetragonal system in cells of dimensions a = 5.6046(4) A, c = 13.154(1) A for Rb(2)TiCu(2)S(4), a =6.024(1) A, c = 13.566(4) A for Cs(2)TiAg(2)S(4), and a =5.852(2) A, c =14.234(5) A for Cs(2)TiCu(2)Se(4) at 153 K. Their structure is closely related to that of Cs(2)ZrAg(2)Te(4) and comprises [TiM(2)Q(4)(2)(-)] layers, which are separated by alkali metal atoms. The [TiM(2)Q(4)(2)(-)] layer is anti-fluorite-like with both Ti and M atoms tetrahedrally coordinated to Q atoms. Tetrahedral coordination of Ti(4+) is rare in the solid state. On the basis of unit cell and space group determinations, the compounds K(2)TiCu(2)S(4) and Rb(2)TiAg(2)S(4) are isostructural with the above compounds. The band gaps of K(2)TiCu(2)S(4), Rb(2)TiCu(2)S(4), Rb(2)TiAg(2)S(4), and Cs(2)TiAg(2)S(4) are 2.04, 2.19, 2.33, and 2.44 eV, respectively, as derived from optical measurements. From band-structure calculations, the optical absorption for an A(2)TiM(2)Q(4) compound is assigned to a transition from an M d and Q p valence band (HOMO) to a Ti 3d conduction band.  相似文献   

17.
18.
Electrospray ionization of actinyl perchlorate solutions in H2O with 5% by volume of dimethylformamide (DMF) produced the isolatable gas-phase complexes, [AnVIO2(DMF)3(H2O)]2+ and [AnVIO2(DMF)4]2+, where An = U, Np, and Pu. Collision-induced dissociation confirmed the composition of the dipositive coordination complexes, and produced doubly- and singly-charged fragment ions. The fragmentation products reveal differences in underlying chemistries of uranyl, neptunyl, and plutonyl, including the lower stability of Np(VI) and Pu(VI) compared with U(VI).  相似文献   

19.
We report the syntheses of imprinted polymers using iron-oxo-hydroxo clusters as templates. Three new iron clusters, [Fe(6)O(2)(OH)(2)(O(2)CC(Cl)=CH(2))(12)(H(2)O)(2)] (1), [{Fe(O(2)CC(Cl)=CH(2))(OMe)(2)}(10)] (2) and [Fe(6)O(2)(OH)(2)(O(2)C-Ph-(CH)=CH(2))(12)(H(2)O)(2)] (3) have been prepared from commercially-available carboxylic acids. Cluster-imprinted-polymers (CIPs) of 1, 2 and 3 were prepared with ethylene glycol dimethacrylate monomer, and of 1 with methyl methacrylate monomer. The imprinted sites within the CIPs were examined using EXAFS and diffuse reflectance UV/vis spectroscopy, demonstrating that the clusters 1, 2 and 3 were incorporated intact within the polymers. Extraction of the clusters from the CIPs imprinted with 1 and 3 gave new polymers that showed evidence of an imprinting effect.  相似文献   

20.
The reactions of UO(2)(C(2)H(3)O(2))(2).2H(2)O with K(2)TeO(3).H(2)O, Na(2)TeO(3) and TlCl, or Na(2)TeO(3) and Sr(OH)(2).8H(2)O under mild hydrothermal conditions yield K[UO(2)Te(2)O(5)(OH)] (1), Tl(3)[(UO(2))(2)[Te(2)O(5)(OH)](Te(2)O(6))].2H(2)O (2) and beta-Tl(2)[UO(2)(TeO(3))(2)] (3), or Sr(3)[UO(2)(TeO(3))(2)](TeO(3))(2) (4), respectively. The structure of 1 consists of tetragonal bipyramidal U(VI) centers that are bound by terminal oxo groups and tellurite anions. These UO(6) units span between one-dimensional chains of corner-sharing, square pyramidal TeO(4) polyhedra to create two-dimensional layers. Alternating corner-shared oxygen atoms in the tellurium oxide chains are protonated to create short/long bonding patterns. The one-dimensional chains of corner-sharing TeO(4) units found in 1 are also present in 2. However, in 2 there are two distinct chains present, one where alternating corner-shared oxygen atoms are protonated, and one where the chains are unprotonated. The uranyl moieties in 2 are bound by five oxygen atoms from the tellurite chains to create seven-coordinate pentagonal bipyramidal U(VI). The structures of 3 and 4 both contain one-dimensional [UO(2)(TeO(3))(2)](2-) chains constructed from tetragonal bipyramidal U(VI) centers that are bridged by tellurite anions. The chains differ between 3 and 4 in that all of the pyramidal tellurite anions in 3 have the same orientation, whereas the tellurite anions in 4 have opposite orientations on each side of the chain. In 4, there are also additional isolated TeO(3)(2-) anions present. Crystallographic data: 1, orthorhombic, space group Cmcm, a = 7.9993(5) A, b = 8.7416(6) A, c = 11.4413(8) A, Z = 4; 2, orthorhombic, space group Pbam, a = 10.0623(8) A, b = 23.024(2) A, c = 7.9389(6) A, Z = 4; 3, monoclinic, space group P2(1)/n, a = 5.4766(4) A, b = 8.2348(6) A, c = 20.849(3) A, beta = 92.329(1) degrees, Z = 4; 4, monoclinic, space group C2/c, a = 20.546(1) A, b = 5.6571(3) A, c = 13.0979(8) A, beta = 94.416(1) degrees, Z = 4.  相似文献   

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