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1.
Magnesium (Mg) and zinc (Zn) complexes incorporating tridentate anilido‐aldimine ligand, (E)‐2, 6‐diisopropyl‐N‐(2‐((2‐(piperidin‐1‐yl)ethylimino)methyl)phenyl)aniline ( AA Pip ‐H, 1 ), were synthesized and structurally characterized. The reaction of AA Pip ‐H ( 1 ) with MgnBu2 or ZnEt2 in equivalent proportions afforded the monomeric complex [( AA Pip )MgnBu] ( 2 ) or [( AA Pip )ZnEt] ( 3 ), respectively. The coordination modes of these complexes differ in the solid state: Mg complex 2 shows a four‐coordinated and distorted tetrahedral geometry, whereas Zn complex 3 adopts a trigonal planar geometry with a three‐coordinated Zn center. Complexes 2 and 3 are efficient catalysts for the ring‐opening polymerization of β‐butyrolactone (β‐BL) in the presence of 9‐anthracenemethanol (9‐AnOH). The polymerization of β‐BL with the Zn catalyst system is demonstrated in a living fashion with a narrow polydispersity index, PDI = 1.01–1.10. The number‐averaged molecular weight (Mn) of the produced poly(3‐hydroxybutyrate) (PHB) is quite close to the expected Mn over diverse molar ratios of monomer to 9‐AnOH. A greater ratio of monomer to alcohol catalyzed by Zn complex 3 served to form PHB with a large molecular weight (Mn > 60000). An effective method to prepare PHB‐b‐PCL and PEG‐b‐PHB by the ring‐opening copolymerization of β‐BL catalyzed by zinc complex 3 is reported. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010  相似文献   

2.
Two coordination polymers based on 1, 6‐bis(2‐methyl‐imidazole‐1‐yl)‐hexane (bimh), namely {[Zn3(BTC)2(bimh)] · (bimh)}n ( 1 ) and {[Zn(IPA)(bimh)] · (CH3CH2OH)0.5}n ( 2 ) (H3BTC = trimesic acid, H2IPA = isophthalic acid), were synthesized through hydrothermal reactions. In compound 1 , the zinc(II) ions are bridged by BTC3– ligands to form an undulating infinite two‐dimensional (2D) polymeric network. The 3D networks of 1 show a twofold interpenetrating net. In compound 2 , zinc(II) ions are bridged by IPA2– ligands to form one‐dimensional (1D) helical structures. The 2D structures of 2 are further assembled into 3D networks through aromatic π–π stacking interactions. Both compounds exhibit strong photoluminescence at room temperature and may be good candidates for potential luminescence materials.  相似文献   

3.
Two different coordination polymers are obtained from d10 metal ions [Zn(II) and Cd(II)] and N,N′-ethylenebisacetamide (EBA). {[Zn(EBA)1.5(NO3)]?·?(NO3)} n (1) is a 1-D coordination polymer assembled from zinc ions and EBA molecules acting as a bridging ligand. Cd(H2O)2Cl2(EBA) (2) is constructed from 1-D inorganic polymeric chains {Cd(OH2)2Cl2} n and uncoordinated N,N′-ethylenebisacetamide molecules. These chains are interconnected through hydrogen bonds resulting in a 3-D supramolecular network. The luminescent properties of the organic molecule EBA, as well as of the coordination polymers 1, and 2 have been investigated.  相似文献   

4.
In the structure of the novel zinc complex catena‐poly[[diaqua(4‐hydroxybenzohydrazide)zinc(II)]‐μ‐sulfato], [Zn(SO4)(C7H8N2O2)(H2O)2]n, the complex cations are linked by sulfate counter‐ions into helical polymeric chains extending along the b axis. Each helix is stabilized by six intrachain hydrogen bonds involving stronger O—H...O (1.83–2.06 Å) and weaker N—H...O (2.20–2.49 Å) interactions. The ZnII atom displays a distorted octahedral geometry formed by the 4‐hydroxybenzohydrazide ligand, two water molecules and two SO42− ions, which is very similar to the metal‐atom environment in a previously reported CoII complex [Zasłona, Drożdżewski & Kubiak (2010). J. Mol. Struct. 982 , 1–8], especially the Zn—O and Zn—N bond lengths of 2.0453 (12)–2.1602 (9) and 2.1118 (12) Å, respectively.  相似文献   

5.
Three zinc complexes based on 2,6-bis(N-2-pyridylmethyl)formimidoyl-4-methylphenolate (HL) by employing Zn(ClO4)2, Zn(CH3COO)2, and ZnCl2 have been synthesized and investigated as functional models of phosphoesterases. The molecular structure of [{Zn2L(µ 3-OH)(H2O)}2](ClO4)4 (1) obtained by reacting zinc perchlorate with HL was determined by X-ray diffraction analysis, revealing a tetranuclear species with four zinc centers and two ligands. Two zinc ions are accommodated within the two compartments of each ligand and are bridged by an additional hydroxide leading to Zn–Zn distances of 3.1235(9) and 3.1268(9)?Å, respectively. The hydroxide is involved in an additional bridge to the second LZn2 moiety forming a µ 3-OH. A water molecule is coordinated to two of the four zinc ions. The occurrence of a hydroxide group and of a coordinated water is relevant to the structure found in the native enzyme. The hydrolysis of the phosphoester bis(p-nitrophenol)phosphate ester (BNPP) in a mixture of DMSO and water at 50°C catalyzed by the three zinc compounds has been investigated. High hydrolytic activity was found for all three compounds but differed significantly depending on the nature of the counterion; the chloro derivative was found to be most active, while the perchlorate compound showed the least activity.  相似文献   

6.
Two new coordination complexes, [Zn(IA)2(phen)] (1) and [Zn(IA)2(4,4′-bipy)] n ?·?C2H5OH (2) (IAH?=?indole-3-acetic acid, phen?=?1,10-phenanthroline, 4,4′-bipy?=?4,4′-bipyridine), have been prepared and characterized by single-crystal X-ray diffraction. Complex 1 is mononuclear and 2 presents a 1-D zigzag chain, in which 4,4′-bipy connects the Zn(II) ions. Both complexes show fluorescence emissions and exhibit fluorescence quenching when Hg2+ ions are present. ICP, EDS, and SEM experiments reveal that zinc in both complexes can be exchanged by toxic mercury ions.  相似文献   

7.
Seven crystal structures of five first‐row (Fe, Co, Ni, Cu, and Zn) and one second‐row (Cd) transition metal–4‐picoline (pic)–sulfate complexes of the form [M(pic)x]SO4 are reported. These complexes are catena‐poly[[tetrakis(4‐methylpyridine‐κN)metal(II)]‐μ‐sulfato‐κ2O:O′], [M(SO4)(C6H7N)4]n, where the metal/M is iron, cobalt, nickel, and cadmium, di‐μ‐sulfato‐κ4O:O‐bis[tris(4‐methylpyridine‐κN)copper(II)], [Cu2(SO4)2(C6H7N)6], catena‐poly[[bis(4‐methylpyridine‐κN)zinc(II)]‐μ‐sulfato‐κ2O:O′], [Zn(SO4)(C6H7N)2]n, and catena‐poly[[tris(4‐methylpyridine‐κN)zinc(II)]‐μ‐sulfato‐κ2O:O′], [Zn(SO4)(C6H7N)3]n. The Fe, Co, Ni, and Cd compounds are isomorphous, displaying polymeric crystal structures with infinite chains of MII ions adopting an octahedral N4O2 coordination environment that involves four picoline ligands and two bridging sulfate anions. The Cu compound features a dimeric crystal structure, with the CuII ions possessing square‐pyramidal N3O2 coordination environments that contain three picoline ligands and two bridging sulfate anions. Zinc crystallizes in two forms, one exhibiting a polymeric crystal structure with infinite chains of ZnII ions adopting a tetrahedral N2O2 coordination containing two picoline ligands and two bridging sulfate anions, and the other exhibiting a polymeric crystal structure with infinite chains of ZnII ions adopting a trigonal bipyramidal N3O2 coordination containing three picoline ligands and two bridging sulfate anions. The structures are compared with the analogous pyridine complexes, and the observed coordination environments are examined in relation to crystal field theory.  相似文献   

8.
Ethyl 2-(vinyloxy)ethoxyacetate ( 4 ; CH2?CH? OCH2CH2OCH2? COOC2H5), a vinyl ether having both carboxylic acid ester and oxyethylene unit in its pendant, afforded well-defined living polymers when polymerized by the hydrogen iodide/iodine (HI/I2) initiating system in toluene at ?40°C. The polymers possessed a narrow molecular weight distribution (M w/M n ≤ 1.15), and their molecular weight (M n) increased proportionally to monomer conversion or the molar ratio of the monomer to hydrogen iodide. The polymer molecular weight also increased upon addition of a fresh feed of the monomer to a completely polymerized reaction mixture. Polymers of high molecular weights (M n > 5 × 105) and broad molecular weight distributions were obtained by BF3OEt2 in toluene at ?40°C. Polymerization rate of 4 with HI/I2 is ca. 100 times greater than that of the corresponding alkyl vinyl ether, and thus 4 was found to be one of the most reactive vinyl ethers thus far studied. Alkaline hydrolysis of the pendant ester groups of the polymers gave a vinyl ether-based polymeric carboxylic acid 6 with a narrow molecular weight distribution.  相似文献   

9.
To improve the therapeutic efficacy of 20(s)-camptothecin (CPT) polymeric drugs containing CPT have been designed. A new CPT-conjugate, 3,6-endo-methylene-1,2,3,6-tetrahydrophthalimidoacetamidoglycine camptothecin ester (ETPA-gly-CPT), was synthesized by linking its hydroxyl group to the phthalimido monomer through a glycine-glycine spacer. Its homo- and copolymer with acrylic acid (AA) were prepared by photopolymerization using 2,2-dimethoxy-2-phenylacetophenone (DMP) as a photoinitiator. The monomer and its polymers were characterized by IR, 1H- and 13C-NMR spectra. The ETPA-gly-CPT content in poly(ETPA-gly-CPT-co-AA) obtained by elemental analysis was 40 wt.%. The number-average molecular weights of the polymers determined by gel permeation chromatography were as follows: Mn=15,000 for poly(ETPA-gly-CPT), Mn=18,700 for poly(ETPA-gly-CPT-co-AA). The IC50 values of ETPA-gly-CPT and its polymers against cancer cells were much larger than that of CPT.  相似文献   

10.
Zinc(II) coordination polymers, [Zn(Hmal)(im)(H2O)] n · 2nH2O (1) and [Zn(Hmal)(bpy)] n · 3nH2O (2) (H3mal = malic acid, im = imidazole, bpy = 2,2′-bipyridine), were synthesized from aqueous solution and characterized by elemental analyses, infrared and fluorescence spectra, thermogravimetric analyses, and single-crystal X-ray structural analyses. In 1, zinc is coordinated by imidazole, water, and tridentate malate in octahedral geometry. The β-carboxy group of malate further bridges with the other zinc forming 1-D polymeric chains. A pair of 1-D chains self-assemble to generate a double chain by strong hydrogen bonds between imidazole and malate. Furthermore, neighboring pairs of double chains are extended to form the final 3-D framework through intermolecular hydrogen bonds. In 2, the malates link Zn in a bidentate–monodentate fashion to form spiral-shaped chains that extend into a 3-D supramolecular structure by π–π stacking interactions and intermolecular hydrogen bonds. Complex 1 exhibits strong fluorescence at room temperature.  相似文献   

11.
Freebase 5,10,15,20-tetra(4-pyridyl)porphyrin (TPyP) is able to assemble into crystalline rigid 1D and 2D metallosupramolecular arrrays via exocyclic coordination with tetracoordinate and hexacoordinate metal ions, respectively. In this contribution we report on two coordination polymers of μ 4-bridging freebase TPyP with zinc and manganese halide moieties. The structure of [(ZnBr2)2TPyP] · 6 TCE (2) (TCE = 1,1,2,2-tetrachloroethane) consists of 1D polymeric chains. The topology of [(MnCl2)TPyP] · 6 TCE (3) is the (4,4) square grid type. The crystal structure of the known compound [(HgI2)2TPyP] · 4 TCE (1) was redetermined by X-ray crystallography.  相似文献   

12.
In this work, a benzenedinitrile functionalized monomer, 2‐methyl‐acrylic acid 6‐(3,4‐dicyano‐phenoxy)‐hexyl ester, was successfully polymerized via the reversible addition‐fragmentation chain transfer method. The polymerization behavior conveyed the characteristics of “living”/controlled radical polymerization: the first‐order kinetics, linear increase of number‐average molecular weight with monomer conversion, narrow molecular weight distribution, and successful chain‐extension experiment. The soluble Zn(II) phthalocyanine (Pc)‐containing (ZnPc) polymers were achieved by post‐polymerization modification of the obtained polymers. The Zn(II) phthalocyanine‐functionalized polymer was characterized by FTIR, UV–vis, fluorescence, atomic absorption spectroscopy, and thermogravimetric analysis. The potential application of above ZnPc‐functionalized polymer as electron donor material in bulk heterojunction organic solar cell was studied. The device with ITO/PEDOT:PSS/ZnPc‐Polymer/PC61BM/LiF/Al structure provided a power conversion efficiency of 0.014%, fill factor of 0.24, open circuit voltage (Voc) of 0.21 V, and short‐circuit current (Jsc) of 0.28 mA/cm2. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 691–698  相似文献   

13.
A series of meso‐tetrakis‐(ERE donor) zinc(II) porphyrins n Zn (ERE donor=4‐R‐3,5‐bis[(E)‐methyl]phenyl; 1 Zn: E=NMe2, R=Br; 2 Zn: E=NMe2, R=H; 3 Zn: E=OMe, R=Br; 4 Zn: E=OMe, R=H) have been synthesized in excellent yields. As a result of the combination of a Lewis acidic site and eight Lewis basic sites within one molecule, monomeric molecules of n Zn self‐assemble to form one‐dimensional porphyrin polymers [ n Zn] in the solid state, as confirmed for 1 Zn and 3 Zn by X‐ray crystallography. The coordination environment around the zinc(II) ions in these polymers is octahedral. They are ligated by four equatorial nitrogen atoms of the porphyrin and two apical E atoms (E=N, O) provided by the EBrE donor groups of adjacent n Zn molecules. Complexes 2 Zn and 4 Zn did not form single crystals, but solid‐state UV/Vis analysis points to the formation of similar structures. Solution UV/Vis and 1H NMR spectroscopy indicated that interactions between 1 Zn and 2 Zn monomers in the polymers are stronger than between 3 Zn and 4 Zn monomers. Interestingly, they also revealed that the presence of a neighboring bromine atom in the EBrE donor groups has a considerable influence on the coordination properties of the benzylic N or O atoms. The zinc(II) ions of the porphyrins most likely adopt only hexacoordination in the solid state, owing to the unique predisposition of Lewis acidic and basic sites in the n Zn molecules. Several parameters of the aggregates, for example, the interplanar separation between porphyrins and the zinc–zinc distances, change as a function of the coordinating E groups. The high degree of modularity in their synthesis makes these zinc(II) porphyrins an interesting new entry in noncovalent multiporphyrin assemblies.  相似文献   

14.
With regard to crystal engineering, building block or modular assembly methodologies have shown great success in the design and construction of metal–organic coordination polymers. The critical factor for the construction of coordination polymers is the rational choice of the organic building blocks and the metal centre. The reaction of Zn(OAc)2·2H2O (OAc is acetate) with 3‐nitrobenzoic acid (HNBA) and 4,4′‐bipyridine (4,4′‐bipy) under hydrothermal conditions produced a two‐dimensional zinc(II) supramolecular architecture, catena‐poly[[bis(3‐nitrobenzoato‐κ2O,O′)zinc(II)]‐μ‐4,4′‐bipyridine‐κ2N:N′], [Zn(C7H4NO4)2(C10H8N2)]n or [Zn(NBA)2(4,4′‐bipy)]n, which was characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single‐crystal X‐ray diffraction analysis. The ZnII ions are connected by the 4,4′‐bipy ligands to form a one‐dimensional zigzag chain and the chains are decorated with anionic NBA ligands which interact further through aromatic π–π stacking interactions, expanding the structure into a threefold interpenetrated two‐dimensional supramolecular architecture. The solid‐state fluorescence analysis indicates a slight blue shift compared with pure 4,4′‐bipyridine and HNBA.  相似文献   

15.
The title compound, [Zn3(C9H21SiS)6] or [(iPr3SiS)Zn(μ‐SSiiPr3)2Zn(μ‐SSiiPr3)2Zn(SSiiPr3)], is the first structurally characterized homoleptic silanethiolate complex of zinc. A near‐linear arrangement of three ZnII ions is observed, the metals at the ends being three‐coordinate with one terminally bound silanethiolate ligand. The central ZnII ion is four‐coordinate and tetrahedral, with two bridging silanethiolate ligands joining it to each of the two peripheral ZnII ions. The nonbonding intermetallic distances are 3.1344 (11) and 3.2288 (12) Å, while the Zn...Zn...Zn angle is 172.34 (2)°. A trimetallic silanethiolate species of this type has not been previously identified by X‐ray crystallography for any element.  相似文献   

16.
Multidentate N‐heterocyclic compounds form a variety of metal complexes with many intriguing structures and interesting properties. The title coordination polymer, catena‐poly[zinc(II)‐bis{μ‐2‐[(1H‐imidazol‐1‐yl)methyl]‐1H‐benzimidazole}‐κ2N3:N3′;N3′:N3‐zinc(II)‐bis(μ‐benzene‐1,2‐dicarboxylato)‐κ2O1:O23O1,O1′:O2], [Zn2(C8H4O4)2(C11H10N4)2]n, has been synthesized by the reaction of Zn(NO3)2 with 2‐[(1H‐imidazol‐1‐yl)methyl]‐1H‐benzimidazole (imb) and benzene‐1,2‐dicarboxylic acid (H2bdic) under hydrothermal conditions. There are two crystallographically distinct imb ligands [imb(A) and imb(B)] in the structure which adopt very similar coordination geometries. The imb(A) ligand bridges two symmetry‐related Zn1 ions, yielding a binuclear [(Zn1)2{imb(A)}2] unit, and the imb(B) ligand bridges two symmetry‐related Zn2 ions resulting in a binuclear [(Zn2)2{imb(B)}2] unit. The above‐mentioned binuclear units are further connected alternately by pairs of bridging bdic2− ligands, forming an infinite one‐dimensional chain. These one‐dimensional chains are further connected through N—H...O hydrogen bonds, leading to a two‐dimensional layered structure. In addition, the title polymer exhibits good fluorescence properties in the solid state at room temperature.  相似文献   

17.
The structure of the title compound, poly­[zinc(II)‐bis(μ‐octanoato‐O:O′)], [Zn(C8H15O2)2]n, consists of polymeric sheets parallel to (100) in which tetrahedrally coordinated Zn2+ cations are connected by carboxyl­ate bridges in a synanti arrangement.  相似文献   

18.
Reactions of hydrated zinc(II) trifluoroacetate and sodium azide with two tridentate Schiff bases HL1 (2-((E)-(2-(dimethylamino)ethylimino)methyl)-4-chlorophenol) and HL2 (2-((E)-(2-(dimethylamino)ethylimino)methyl)-4-bromophenol) under the same reaction conditions yielded two dinuclear isostructural zinc(II) complexes, [Zn(L1)(N3)]2 (1) and [Zn(L2)(N3)]2 (2), respectively. The complexes were characterized systematically by elemental analysis, UV–Vis, FT-IR, and 1H NMR spectroscopic methods. Single-crystal X-ray diffraction studies reveal that each of the dinuclear complexes consists of two crystallographically independent zinc(II) ions connected by double bridging phenoxides. All zinc(II) ions in 1 and 2 are surrounded by similar donor sets and display distorted square–pyramidal coordination geometries. The ligands and complexes reveal intraligand 1(π → π*) flourescence. The enhancement of the fluorescence intensities for the complexes compared to the ligands indicates their potential to serve as photoactive materials.  相似文献   

19.
The 2-methylimidazole complexes of Co(II), Ni(II), Cu(II) and Zn(II) orotates, mer-[Co(HOr)(H2O)2(2-meim)2] (1), mer-[Ni(HOr)(H2O)2(2-meim)2] (2), [Cu(HOr)(H2O)2(2-meim)] (3) and [Zn(HOr)(H2O)2(2-meim)] (4), were synthesized and characterized by elemental analysis, spectral (UV–Vis and FT-IR) methods, thermal analysis (TG, DTG and DTA), magnetic susceptibility, antimicrobial activity studies and single crystal X-ray diffraction technique. The complexes 1 and 2 have distorted octahedral geometries with two monodentate 2-methylimidazole and one bidentate orotate and two aqua ligands. The complexes 3 and 4 have distorted square pyramidal and trigonal bipyramidal geometry, respectively, with one 2-methylimidazole, bidentate orotate and aqua ligands. The orotate coordinated to the metal(II) ions through deprotonated nitrogen atom of pyrimidine ring and oxygen atom of carboxylate group as a bidentate ligand. The antimicrobial activities of 1 and 4 were found to be more active gram (+) than gram (−) and 4 could be use for treatment Staphylococcus aureus.  相似文献   

20.
catena‐Poly[[[tetra­aqua­zinc(II)]‐μ‐4,4′‐bipyridine‐κ2N:N′] [[μ‐thio­sulfato‐κ2O:S‐bis­[(thio­sulfato‐κS)zinc(II)]]‐di‐μ‐4,4′‐pyridine‐κ4N:N′] dihydrate], {[Zn(C10H8N2)(H2O)4][Zn2(S2O3)3(C10H8N2)2]·2H2O}n, is a polymeric zinc complex built up from thio­sulfate‐containing anionic chains, where the Zn atom is tetra­hedrally coordinated, and aqua‐containing cationic chains incorporating octa­hedrally coordinated Zn. In each type of chain, the 4,4′‐bipyridine units act as spacers, and the chains run along three non‐inter­secting almost orthogonal directions in space. The profusion of hydrogen‐bond donors (all the H atoms of the water mol­ecules) and acceptors (the thio­sulfate O and S atoms) generates a very complex hydrogen‐bonding scheme.  相似文献   

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