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1.
1 INTRODUCTION 1, 2, 4-Triazole and its derivatives have gained great attention as ligands to transition metals by the fact that they unite the coordination geometry of both pyrazoles and imidazoles, and in addition exhibit a strong and typical property of acting as bridging ligands between two metal centers. In this bridging capacity, the 1, 2, 4-triazole ligands show a great coordination diversity, especially when the triazole nucleus are substituted with additional donor groups[1]. In…  相似文献   

2.
Three new Zn(Ⅱ)/Cd(Ⅱ) coordination polymers based on 2-mercaptonicotinic acid (H2mna) with 1,2-di(4-pyridyl)ethylene (dpe) introduced as a bridging ligand have been synthesized via hydrothermal method and structurally characterized by single-crystal X-ray diffraction as well as elemental analysis and IR. As reported in this paper, [Zn2(dpe)0.5(mna)2] (1) can be classified as a two-dimensional layer structure in which the 1D chain composed of Zn(Ⅱ) and mna ligands is bridged by dpe ligands, while the complex named [Zn4(dpe)4(mna)4] (2) is a tetra-nuclear cluster compound. These two compounds are further extended to three-dimensional structures by hydrogen bonds along with C-H…π and π…π interactions. Compound 3 with general formular [Cd2(dpe)0.5(mna)2]·H2O belongs to a three-dimensional porous structure in which the 2D metal layers formed by the coordination of Cd(Ⅱ) and mna ligands are connected with the bridging of dpe ligands.  相似文献   

3.
1 INTRODUCTION Much research interest has been focused on metal- organic coordination polymers in past years because of the structural and topological novelty of these compounds and their potential applications as func- tional materials, such as catalyst, ion-exchange, gas sorption, optical material and molecule-based ma- gnet[1~6]. In this field, many organic bridging ligands such as bipyridine, polyaromatic carboxylate and re- lated species have been used to produce various types of met…  相似文献   

4.
1INTRODUCTION There has been considerable interest in the designand synthesis of transition metal complexes withcarboxylate ligands in coordination chemistry due tothe fact that this type of complexes has potentialapplications in molecule-based magnets,catalysis,supramolecular chemistry and biological systems[1~3].As an important flexibility dicarboxylate ligand,malonate dianion may act as momodentate,chelatedbidentate and tridentate bridging ligands to formvarious1D,2D and3D structures[…  相似文献   

5.
The novel octadecanudear Cu-RE cluster haw been isolated from the reaction system of aqueous Cu2+-RE3+-pyb (RE=Sm, Eu; pyb=pyridine betaine) and characterized by single-crystal structural analysis. The results show that the clusters comprise a [Cu12RE6(μ3-OH)24(μ12-ClO4)]17+ octahedral core, which encapsulates a ClO4- ion and has 18 water molecules and 12 bridging pyb carboxylato ligands as external ligands.  相似文献   

6.
1 INTRODUCTION It is well known that the bi-functional 4,4?-bi- pyridine (4,4?-bpy) has the ability to act as a rigid, rod-like organic building block in the self-assembly of coordination frameworks. Many researches have also been done on the metal oxalate compounds. The remarkable coordination abilities of oxalate and 4,4?- bpy ligands are applied to design and synthesize new polymeric coordination complexes[1~4] containing mixed bridging ligands. Manganese is one of the several first-r…  相似文献   

7.
<正> Introduction. Copper (Ⅱ) complexes have plentiful and variable steric structures. It plays an important role in a lot of enzymatic reactions. Especially,the active component of some enzymes has a binuclear copper core with bridging ligands. Besides, lots of one-dimension molecular chains and polymers are studied as model of one-dimension conductors. ~ ~  相似文献   

8.
A novel one-dimensional manganese(Ⅱ) complex containing nitronyl nitroxide radical [Mn2(IM2-py)2(Ac)2((μ1.1-N3)(μ1,3-N3) . EtOH]n was synthesized and characterized structurally and magnetically. It crystallizes in the monoclinic space group p21/n. Each Mn(Ⅱ) ion is six-coordinated in a distorted octahedral environment. The two N atoms of the nitronyl nitroxide radical and the two O atoms of acetate ligands are in the equatorial plane, whereas the two different azido bridging ligands are in trans axial position. Mn(Ⅱ) ions are linked by nitrogen atom of μ1,1-azido and oxygen atoms of two carboxy groups to form a Mn-Mn unit. Mn-Mn units are linked by azido ligands through u1,3 bridging style to form a one-dimensional chain. The compound is connected by the coordination bonds,π-π interactions and hydrogen bonds as a three-dimensional structure. Magnetic susceptibility data support that there are stronger antiferromagnetic interactions between the radical and Mn(Ⅱ) ion, weak antiferromagnetic inter  相似文献   

9.
1 INTRODUCTION Crystal engineering and the design of solid-state architectures have recently become areas of increasing interest[1, 2]. Such crystal engineering may afford new materials with useful properties such as catalytic activity, micro-porosity, nonlinear optical activity, cooperative magnetic behavior and so on. Polynitrile-ligand is one of the ideal multi-functional ligands for crystal engineering and many complexes with polynitriles as ligands have been found to show the spe…  相似文献   

10.
1 INTRODUCTION 1,2,4-Triazole and its derivatives are very useful compounds due to their broad spectrum of pharmacological activities, such as antitumor[1], antiviral[2 ~ 4], antibacterial[5] and antifungal[6] activities. Moreover, they can be used as ver- satile ligands for transition metals. Particularly, they exhibit a strong and typical property of act- ing as bridging ligands between two metal cen- ters[7, 8]. 3-Substituted thio-1H-1,2,4-triazole is the important 1,2,4-triazole deri…  相似文献   

11.
2-fluorobenzoic acid (2-HFBA) and 2,2′-bipyridine (2,2′-bpy) was used as ligands to react with lanthanum to obtain a complex, [La(2-FBA)3·(2,2′-bpy)]2. The structure of the complex contains three independent molecules. In two of them, the two central metal ions are connected together through four 2-FBA groups by bidentate bridging and chelating-bridging two modes. In another, the two central metal ions are connected together through four bidentate bridging 2-FBA groups.  相似文献   

12.
Using the V-shaped oba dianions as bridging ligands and dpa molecules as terminal ligands, a new 1D helical coordination-polymeric chain, [Zn(oba)(dpa)]n [oba=oxybis(4-benzoate), dpa=di(2-pyridyl)amine], was synthesized and characterized by single-crystal X-ray diffraction, elemental analyses, UV-Vis and IR spectra, and TGA analysis. X-ray structural analysis revealed that, oba and dpa ligands played an important role in the self-assembly of the helical chains by providing potential supramolecular recognition sites for π-π aromatic stacking and hydrogen-bond interactions, resulting in the self-assembly of the (4,4) networks to give a 3-D supramolecular framework. The photoluminescence properties of the title compound were also investigated, showing intense blue photoluminescence properties at room temperature.  相似文献   

13.
Introduction Transition metal coordination polymers of one-, twoand three-dimensional infinite frameworks have been aattractive research area because of their diverse structures and useful properties.1,2 Polydentate ligands, whicare used as bridges in constructing the coordinatiopolymers are quite important in the crystal engineerinof supramolecular architecture organized by coordinatcovalent or hydrogen bonding.3 2,2'-Bipyridyl-3,3dicarboxylate (bpdc) is a potential bridging ligand ivariou…  相似文献   

14.
<正> The crystal structure of [Eu2(Met)3(Gly)(H2O)2](ClO4)6(Met=CH3-S(CH2)2CHNH2COOH, Gly=NH2CH2COOH) belongs to monoclinic system with space group P21/n.The final R is 0.060. The Met and Gly are bonded as bidentate bridging ligands to Eu(III) atoms.  相似文献   

15.
1 INTRODUCTION cited state by the intense spin-obital coupling of Ag?, and the energy gap between triplet excited state and The study of photoluminescent properties of d10 singlet ground state is very small, which causes lu- metal complexes has been receiving current atten- minescence quenching of Ag? complex[15, 16 ] . tion. A number of polynuclear complexes of Au, Ag, In this paper, we report the synthesis and struc- and Cu containing bridging phosphine ligands have tural characterizat…  相似文献   

16.
The title compound [Cu (ADC) (2, 2'-bipy)]n (ADC = C2 (COO)2^2.) was prepared and characterized by elemental analysis, IR spectroscopy, X-ray analysis, respectively. The analysis of the crystal structure reveals that the copper atom is five-coordinated with two nitrogen atoms of 2, 2'-bipy and three oxygen atoms of different acetylenedicarboxylate dianions. ADC as bridging ligands link the Cu (Ⅱ) ions, forming coordination polymer structure.  相似文献   

17.
The title complex, {[Cd2(1,8-nap)2(H2O)2](bpp)2}n(1), a cadmium complex based on mixed naphthalene-1,8-dicarboxylate (1,8-nap) and flexible 1,3-bi(4-pyridyl)propane (bpp) ligands, has been hydrothermally synthes-ized. It consists of a one-dimensional chain along c axis, which is derived from dimeric unit [Cd2(1,8-nap)2(H2O)2] linked by a pair of bpp ligands. In every [Cd2(1,8-nap)2(H2O)2] dimeric unit, two 1,8-nap act as bridging ligands to connect two Cd(Ⅱ) atoms, forming a sixteen-membered ring. Each Cd(Ⅱ) atom is in a distorted octahedral environment, coordinated by one aqua, two 1,8-nap and two bridging bpp ligands. In addition, two bridging bpp ligands connected two neighboring Cd(Ⅱ) atoms form a twenty-four-membered ring. The TGA and Luminescence property in solid state of complex 1 have been further studied and discussed in this paper. CCDC: 669293.  相似文献   

18.
1 INTRODUCTION Coordination polymers have attracted the atten- tion of chemists, physicists, and materials scientists owing to their fascinating structures and potential functional applications in the last decade[1~4]. The bridging ligands play a central role in constructing functional coordination polymers, and weak nonco- valent interactions like hydrogen bonding or π-π stacking plays an important role in molecular self- assembly[5~7]. As a multidentate and rigid ligand with multi-pr…  相似文献   

19.
1 INTRODUCTION In the design of crystal molecule, inorganic crystal engineering is one of the focused fields that are ever developing[1]. The introduction of different metal ions and bridging ligands often gives rise to novel physical and chemical properties[2~4]. Conse- quently, the supramolecular compounds constructed from weak interactions, such as hydrogen bond, π-π stacking, C–H???O interaction, ion-π interaction and hy- drophobing interaction, have become the new focus of cryst…  相似文献   

20.
1INTRODUCTION The employment of transition metal ions and ap-propriate bridging ligands has become a dominant theme in the construction of some interesting ar-rays[1,2],especially for the large square grid net-works.Recently,considerable research effort has been focused on the studies of polymeric frame-works with the ligands based on imidazole.These polymers are of great interest not only due to their intriguing topologies but also the potential applications in ion exchange,magnetic and e…  相似文献   

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