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1.
1 INTRODUCTION Since the report about unusual coordination num- bers and arrangements to metal ions of crown ether compounds by Pedersen[1], the crown ether compounds have attracted much attention. Due to their novel coordination modes, crown ethers have been widely used in catalyst, solvent extraction, iso- tope separation, bionics, material chemistry, host- guest chemistry and supramolecular chemistry[2~5]. So it is vital to study the synthesis of new crown ethers and their crystal stru…  相似文献   

2.
Much attention has been paid to the amide-type open-chain crown ethers with versatile mo-lecular structures because of their characteristic physical and chemical properties. These types of ligands have been used successfully as the active materials for ion-selective electrodes and the extractants for metal ions[1—5]. Among these ligands, N,N,N′,N′-tetraphenyl-3,6,9-trioxaun- decanediamide (TTD) shows the high extractabilities for Sr2+, Ba2+ and rare earth ions and the good selectivity to…  相似文献   

3.
The extensive pioneering study of Pedersen I has led to a vialal explosion of solutionand solid-state investigation of crown ethers and metal ions which include alkali metal,alkali earth metal, other main-group and transition-metal ions. It is shown that singlecrystal X-ray diffraction analysis is a most powerful technique for the characterization ofthese complexes and numerous solid-state structUral stIJdies have appeared through theyears. The reported B15CS complexes strllcturally charact…  相似文献   

4.
Using metal ions to control the self-assembly of metallosupramolecules of varying architecture is one of the fascinating developments in supramolecular chemistry[1,2],particularly those concerned with the deliberate construction of molecular aggregates,like helices,rotaxanes,catenanes,knots,cages[3~6] and the crystal engineering of two or three dimensional networks with varied topology and interpenetration[7~10].Coordination bonds have proved themselves to be one of the most useful connectors in supramolecular self-assembly due to their versatile geometrical modes(e.g.linear,trigonal,square plane,tetrahedral,octahedral) in bond formations.By careful design of tailored ligands,various novel supramolecular architectures have been constructed.Recently,angular bi- or tridentate and other polydentate ligands have aroused a special interest,and a variety of molecular squares,boxes and cages[1~14] with internal cavity or void have been reported,in which many nanoscale structures are formed[6,15,16].We have been interested in the construction of metal based supramolecular structures with polydentate ligands[17~20] and herein report a new metallomacrocyclic complex assembled from two linear polydentate ligands and silver(Ⅰ) nitrate.  相似文献   

5.
Recent years, crown ethers have been used in many fields, including phase transfer catalysis, chromatography stationary phase, ionselective electrode, and concentration of metal ions, etc1.. However, the toxicity of free crown ethers makes them unsuitable for industrial use2. Introduction of a crown ether as a functional group to functionalized ionic liquids has been reported3. These functionalized ionic liquids will combine the excellent properties of crown ether and ionic liquids without los…  相似文献   

6.
Three novel benzocrown ether derivatives have been synthesized and their cation binding behavior with uniand bi-valent metal ions was evaluated by the solvent extraction of aqueous metal picrates. The obtained results indicate that the size-fit of crown ether and metal cation, and electron effect of the side arm attached to benzocrown ethers affect their cation binding ability and selectivity.  相似文献   

7.
1 INTRODUCTION With the methods of [2+3] and [1+1] tripodal condensation of polyaldehyde with polyamine, many Schiff bases and their relative reduced polyaza cryptands have been facilely synthesized in high yields[1~5]. In this one-step route, some metal ions such as alkali[2, 6, 7], alkali earth[8], rare earth[9, 10] and other transition ions[4, 11, 12] were used as templates[13, 14]. Formerly, the dialdehydes are needed to be rigid structures[15] to prevent themselves from polymeri…  相似文献   

8.
刘育  张衡益 《中国化学》2000,18(1):66-68
Three selena-crown-4 derivatives have been prepared and their cation binding abilities and selectivities with alkali and heavy metal ions have been evaluated by solvent extraction of aqueous metal picrates to show the highest Ag extractability for novel benzo-selena-14-crown-4 (2,3-benzo-7,12-diselena-1, 4-dioxacyclotetradecane-2-ene) over any other crown ethers.  相似文献   

9.
1 INTRODUCTION Metallosupramolecular species with metal-metal interactions have been designed and synthesized due to their potential applications as functional materi- als[1]. For Ag(I) coordination compounds, short Ag(I) –Ag(I) separations have been found in many bi- and polynuclear complexes[2~4], and these short metal- metal distances have been attributed to the ligand ar- chitecture[5, 6]. Thus, the rational design of bi- and polynuclear Ag(I) complexes must recognize the in- here…  相似文献   

10.
1 INTRODUCTION In the past decades, metal disulphides have recei- ved much attention due to their diversity struc- tures[1~4] and applications as potential ligands for metal ions in biological system[5]. Metal disulfide compounds are usually prepared from the direct reactions of metal ions with organic disulphide[1~5], while some others are isolated from the reactions of metal salts and thiolates with the presence of certain oxidizing agents (e.g., O2, H2O2, etc.)[6, 7]. A large number o…  相似文献   

11.
1 INTRODUCTION The class of materials of carbonato metal- organic compounds has received much attention as a consequence of their potential applications in biochemical and environmental protection[1~3]. Many carbonato compounds of Cu2+, Co3+ and Zn2+ etc. have been studied[4~6]. The carbonate anion is a versatile bridging ligand, which can bind metal cations in different modes to generate mononuclear, binuclear, trinuclear, tetranuclear and even 1D, 2D and 3D structures[4, 7, 8]. We…  相似文献   

12.
1 INTRODUCTION Nitronyl nitroxides, independently or in combina- tion with metal ions, have been one of the most widely studied systems in molecular magnetism for understanding the radical-radical or metal-radical interactions as well as for synthesizing organic ferro- magnets and metal-radical magnetic materials[1~3]. Meanwhile, investigations on molecular coordina- tion compounds of lanthanide ions have also attrac- ted great attention due to their luminescence[4, 5] or magnetic propert…  相似文献   

13.
IntroductionOxygen donor macrocycles such as crown ethers are well known to have strong complexation for alkali and alkaline earth ions1. On the other hand, polyazamacrocycles show a high affinity for transition metal ions. Nitrogen-oxygen mixed donor macrocycles can form stable complexes with both alkali and transition metal ions2~5. Most of the macrocycles with mixed donor sites bearing oxygen and sp3 nitrogen atoms, oxygen and sp2 nitrogen atoms, or oxygen and sp3 and sp2 nitrogen atoms hav…  相似文献   

14.
1 INTRODUCTION The transition metal complexes containing ferrocene ligand arouse the interest of chemists because of their novel structures and special properties[1]. The ferrocene derivatives have been used in electrochemistry, in nonlinear optics, and as molecular ferromagnets. Some complexes of 1,1′-bis(diphenylphosphino)ferrocene (dppf) have been synthesized, and many of their crystal structures have been reported by far[2~5]. Here we report the synthesis and crystal structure of a …  相似文献   

15.
冯云龙  刘世雄 《结构化学》2003,22(3):275-278
1 INTRODUCTION Transition metal complexes of N-R-isonitroso- b-ketoimine have received considerable interest, because the isonitroso (oximo) group can coordinate to metal atoms through its oxygen and/or nitrogen atoms to form several geometrical isomers[1~4]. Some palladium(Ⅱ) complexes with N-R-isonitro- soacetylacetoneimine (abbreviated to R-Hiai)[4] and N-R-isonitrosoethylacetoacetate (abbreviated to R- Hieai)[5] have been reported. Here we will report the structure of a palladi…  相似文献   

16.
1INTRODUCTION Over the past decades,olefin oligomerization and polymerization based on late transition metal catalysts have been the most exciting developments in the area of organometallic chemistry and polymer science[1~3].In this broad context,neutral nickel(II)complexes have attracted much attention for their less sensitivity to protonic solvents and polar mon-mers.The most typical one is the SHOP-type cata-lyst[4~6],which contains an anionic[P,O]chelate ring and shows high activ…  相似文献   

17.
Introduction The study of metal complexes with the crown ether is a quite interesting research field, but the research has mainly focused on the metal complexes with some crown ethers with a relatively small cavity such as 12-crown-4, 15-crown-5 and 18- crown-6 as well as their derivatives. Crown ethers with a larger cavity contain more oxygen atoms, so they have the ability to form the complexes of a higher co-  相似文献   

18.
1 INTRODUCTION Schiff base ligands have played an important role in the development of coordination chemistry as they readily form stable complexes with most metal ions[1~4]. These complexes are very interesting in many fields, such as catalysis and enzymatic reac- tions[5, 6], magnetism and molecular architectures[7~9]. The complexes derived from the similar tridentate Schiff base ligand 2-[(2-dimethylaminoethylimino)- methyl]phenol[10, 11] and its derivatives[12~14] have been widely …  相似文献   

19.
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   

20.
In the past several decades, much attention has been paid to optically active, C2-asymmetric 1,1′-binaphthalene-2,2′-diol and its derivatives because of their application in inducing chirality in asymmetric synthesis[1,2]. Enantiomerically pure 1,1′-binaphthalene-2,2′-diol has been prepared by many methods ranging from the classical resolution via crystallization of the diastereoisomeric salts[3] to asymmetric oxidative coupling[4~6].  相似文献   

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