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1.
The 1,5,6,7,8,8a‐hexahydroimidazo[1,5‐a]pyridine, 3, was quaternized with 2‐(bromomethyl‐1,3,5‐trimethylbenzene, 1,4‐bis(bromomethyl)‐2,3,5,6‐tetramethylbenzene, 2,4‐bis(bromomethyl)‐1,3,5‐trimethylbenzene, 1,3,5‐tris(bromomethyl)‐2,4,6‐trimethylbenzene and 1,3,5‐tris(bromomethyl)‐2,4,6‐triethylbenzene to obtain mono‐, bis‐ and tris‐imidazolinium salts (4–7) which were characterized by elemental analysis and NMR spectroscopy. In order to understand the effects of these changes on the N‐substituent and how they translate to catalytic activity, these new salts (4–7) with Pd(OAc)2 were applied as in situ catalysts for Suzuki‐Miyaura and Heck‐Mirozoki cross‐coupling reactions of aryl chlorides and aryl bromides, respectively. The tris‐imidazolinium salts (7) were found to be more efficient than the related analogs 4–6. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

2.
A series of mixed‐ligand‐based CdII/CoII coordination polymers (CPs) that were derived from two bis(pyridyl)–bis(amide) ligands, 4,4′‐oxybis(N‐(pyridin‐3‐yl)benzamide) ( LP ) and 4,4′‐oxybis(N‐(pyridin‐4‐yl)benzamide) ( LP1 ), and a variety of dicarboxylates isophthalates, terephthalates, 1,2‐carboxytranscinamates, and 1,3‐ and 1,4‐phenylene dicarboxylates were synthesized based on a rationale that they would occlude solvate guests inside their crystal lattice, thereby rendering these CPs suitable as metallogelators. The CPs were characterized by using single‐crystal X‐ray diffraction, elemental analysis, powder X‐ray diffraction (PXRD), FTIR spectroscopy, and thermogravimetric analysis (TGA). Structural analyses revealed that the majority of the CPs were lattice‐occluded molecular solids, which provided us with an opportunity to study their gelation behavior. We observed that, out of eight CPs that were tested, seven were able to produce metallogels. A thorough study of the rheological behavior of the metallogels was performed and CPG1 , CPG2 , CPG4 , and CPG5 were found to exhibit rheoreversible behavior, which was further confirmed by rheological experiments. Interestingly, ligand LP was found to form an aqueous gel, which was exploited to produce silver nanoparticles.  相似文献   

3.
Tripodal 1,3,5‐tris(phenoxymethyl)‐2,4,6‐triethylbenzene analogues have been synthesized and structurally characterized by IR, 1H NMR and 13C NMR spectroscopy and HRMS, and additionally, the single crystal structures of compounds bearing ortho‐ ( 7 ), meta‐ ( 9 ) and para‐hydroxymethyl ( 11 ) functions have been determined by X‐ray diffraction analysis. The structural study revealed that compounds 7 , 9 , and 11 do not adopt the expected 1,3,5‐alternate conformation in the solid state. The packing diagrams of compounds 7 , 9 , and 11 revealed that six hydrophilic hydroxymethyl groups from six individual molecules ( 7 , 9 and 11 ) were arranged in close contact via intermolecular hydrogen‐bond interactions. For compounds 7 and 9 , the six hydroxyl groups formed a distorted hexagonal ring; however, formation of such a hexagonal ring was not clear in the case of compound 11 . Compounds 9 and 11 were found to form hydrophobic cavities via intermolecular hydrogen‐bond interactions in the solid state, and the cavities were occupied by two ethyl groups from the two cavity‐forming molecules.  相似文献   

4.
《化学:亚洲杂志》2018,13(15):1941-1949
A newly synthesized bis‐pyridyl ligand having a diphenyl ether backbone ( LP6 ) displayed the ability to form crystalline coordination polymers ( CP1‐CP6 ) which were fully characterized by single crystal X‐ray diffraction. Most of the resulting polymers were lattice‐occluded crystalline solids—a structural characteristic reminiscent to gels. The reactants of the coordination polymers produced metallogels in DMSO/water confirming the validity of the design principles with which the coordination polymers were synthesized. Some of the metallogels displayed material properties like in situ synthesis of Ag nanoparticles and stimuli‐responsive gel–sol transition including sensing hazardous gases like ammonia and hydrogen sulfide.  相似文献   

5.
Two new coordination polymers, namely poly[[hexathiocyanatotetrakis{μ3‐2,4,6‐trimethyl‐1,3,5‐tris[(triazol‐1‐yl)methyl]benzene}tricadmium(II)] 3.5‐hydrate], {[Cd3(SCN)6(C18H21N9)4]·3.5H2O}n ( 1 ), and poly[[hexathiocyanatotetrakis{μ3‐2,4,6‐trimethyl‐1,3,5‐tris[(triazol‐1‐yl)methyl]benzene}trizinc(II)] 3.5‐hydrate], {[Zn3(SCN)6(C18H21N9)4]·3.5H2O}n ( 2 ), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy and single‐crystal X‐ray diffraction analysis. From the X‐ray analysis, it is noteworthy that polymers 1 and 2 are isostructural, with their three‐dimensional structures composed of three kinds of four‐connection metal ions and two kinds of three‐connection 2,4,6‐trimethyl‐1,3,5‐tris[(triazol‐1‐yl)methyl]benzene (TTTMB) ligand nodes. Each metal ion is six‐coordinated in a slightly distorted octahedral geometry. The antioxidant activity against DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) and the antidiabetic activity against α‐amylase of the synthesized compounds were evaluated in vitro. The results of the DPPH free‐radical scavenging assay showed that polymers 1 and 2 exhibited strong antioxidant effects, with IC50 values of 3.81 and 2.56 mg ml?1, respectively. The IC50 value in the antidiabetic studies of polymer 1 was 3.94 mg ml?1, while polymer 2 exhibited no antidiabetic activity. Polymers 1 and 2 revealed different inhibitory activities on DPPH and α‐amylase, which indicated that the metal ions play important roles in the biological activity of coordination polymers. In addition, the solid‐state photoluminescence properties and thermal stability of 1 and 2 have been investigated.  相似文献   

6.
By employing the semi‐rigid multidentate carboxylic acid ligand 4,4′,4′′‐{[(2,4,6‐trimethylbenzene‐1,3,5‐triyl)tris(methylene)]tris(oxy)}tribenzoic acid (denoted H3L), a new lanthanum coordination polymer, namely poly[[bis(dimethylformamide)(μ6‐4,4′,4′′‐{[(2,4,6‐trimethylbenzene‐1,3,5‐triyl)tris(methylene)]tris(oxy)}tribenzoato)lanthanum(III)] dimethylformamide tetrasolvate 0.25‐hydrate], {[La(C33H27O9)(C3H7NO)2]·4C3H7NO·0.25H2O}n or {[La(L)(DMF)2]·4(DMF)·0.25(H2O)}n (DMF is dimethylformamide) ( 1 ), was prepared and characterized by single‐crystal X‐ray diffraction, elemental analysis, thermogravimetric analysis, IR spectroscopy and photoluminescence studies. The asymmetric unit contains one LaIII cation, one anionic L3? ligand, two coordinated DMF molecules, four free DMF molecules and one‐quarter of a free water molecule. Compound 1 possesses (3,6)‐connected two‐dimensional kgd topology sheets consisting of secondary building units of La2 clusters and L3? ligands, which further stack into three‐dimensional supramolecular networks through π–π interactions. Compound 1 exhibits a photoluminescence emission at room temperature, with a peak at 410 nm, owing to a ligand‐centred excited state.  相似文献   

7.
The zinc(II) coordination polymers [Zn(Htatb)(2,2′‐bipy) · (NMP) · H2O] ( 1 ) and [Zn3(tatb)2(2,2′‐bipy)3 · H2O] ( 2 ) (H3tatb = 4,4′,4′′‐s‐triazine‐2,4,6‐triyl‐tribenzoic acid; 2,2′‐bipy = 2,2′‐bipyridyl, NMP = N‐methyl‐2‐pyrrolidon), were synthesized hydrothermally, and characterized by infrared spectroscopy (IR), powder X‐ray diffraction (PXRD), and single‐crystal X‐ray diffraction. Both compounds 1 and 2 possess expectant low dimensional coordination structures, which further connected into interesting 3D networks by hydrogen bond and strong π–π interactions. Moreover, the thermal stabilities and fluorescent properties of 1 and 2 were investigated.  相似文献   

8.
With the rapid development of metal–organic frameworks (MOFs), a variety of MOFs and their derivatives have been synthesized and reported in recent years. Commonly, multifunctional aromatic polycarboxylic acids and nitrogen‐containing ligands are employed to construct MOFs with fascinating structures. 4,4′,4′′‐(1,3,5‐Triazine‐2,4,6‐triyl)tribenzoic acid (H3TATB) and the bidentate nitrogen‐containing ligand 1,3‐bis[(imidazol‐1‐yl)methyl]benzene (bib) were selected to prepare a novel ZnII‐MOF under solvothermal conditions, namely poly[[tris{μ‐1,3‐bis[(imidazol‐1‐yl)methyl]benzene}bis[μ3‐4,4′,4′′‐(1,3,5‐triazine‐2,4,6‐triyl)tribenzoato]trizinc(II)] dimethylformamide disolvate trihydrate], {[Zn3(C24H12N3O6)2(C14H14N4)3]·2C3H7NO·3H2O}n ( 1 ). The structure of 1 was characterized by single‐crystal X‐ray diffraction, IR spectroscopy and powder X‐ray diffraction. The properties of 1 were investigated by thermogravimetric and fluorescence analysis. Single‐crystal X‐ray diffraction shows that 1 belongs to the monoclinic space group Pc. The asymmetric unit contains three crystallographically independent ZnII centres, two 4,4′,4′′‐(1,3,5‐triazine‐2,4,6‐triyl)tribenzoate (TATB3?) anions, three complete bib ligands, one and a half free dimethylformamide molecules and three guest water molecules. Each ZnII centre is four‐coordinated and displays a distorted tetrahedral coordination geometry. The ZnII centres are connected by TATB3? anions to form an angled ladder chain with large windows. Simultaneously, the bib ligands link ZnII centres to give a helical Zn–bib–Zn chain. Furthermore, adjacent ladders are bridged by Zn–bib–Zn chains to form a fascinating three‐dimensional self‐penetrated framework with the short Schläfli symbol 65·7·813·9·10. In addition, the luminescence properties of 1 in the solid state and the fluorescence sensing of metal ions in suspension were studied. Significantly, compound 1 shows potential application as a fluorescent sensor with sensing properties for Zr4+ and Cu2+ ions.  相似文献   

9.
To further explore the coordination possibilities of the flexible tripodal ligand, 4,4′,4′′‐(benzene‐1,3,5‐triyl‐tris(oxy))tribenzoic acid (H3BTTB), two solvent‐controlled three‐dimensional (3D) manganese(II) coordination polymers, [Mn3(BTTB)2(H2O)4](H2O)2 ( 1 ) and [Mn3(BTTB)2(DMF)2](DMF)2 ( 2 ), were synthesized and characterized. Single crystal X‐ray diffraction analysis indicates that in the MnII complexes the BTTB ligands exhibit two coordination modes, which have not been reported previously. Complexes 1 and 2 involve different one‐dimensional (1D) rod‐shaped metal–carboxylate secondary building units (SBUs). The 1D SBUs are further extended to afford two different three‐dimensional (3D) frameworks with similar flu topology via linkage of the BTTB ligands. The results demonstrate that the reaction solvent as well as conformation and coordination mode of BTTB ligands play key roles on the formation of the final framework structures. Additionally, their luminescent properties were investigated.  相似文献   

10.
Based on the tripodal 1,3,5‐tris(imidazol‐1‐yl)benzene (tib) ligand, four transition metal coordination polymers, namely, {[Ni3(tib)2(H2O)12] · (SO4)3}n ( 1 ), {[Co1/6(tib)1/3] · (O)1/3}n ( 2 ), and [M(tib)(hip)]n (M = Mn for 3 , and M = Co for 4 ) (hip = 5‐hydroxyisophthalic acid), were synthesized through solvothermal method. Their structures were defined by single‐crystal X‐ray diffraction analyses and further characterized by elemental analyses (EA), IR spectra, powder X‐ray diffraction (PXRD), and thermogravimetric analyses (TGA). Complex 1 displays a 2D 3‐connected (63) hcb net. Complex 2 is a 2D (3,6)‐connected (43)2(46.66.83) kgm net. Complex 3 and 4 present similar 2D 4‐connected (44.62) sql net. Moreover, the solid state luminescence properties of complexes 1 and 3 were investigated.  相似文献   

11.
Iron‐ and nitrogen‐functionalized graphene (Fe‐N‐G), as well as iron‐ and nitrogen‐functionalized oxidized graphene (Fe‐N‐Gox) catalysts were synthesized as non‐noble metal electrocatalysts for oxygen reduction reaction (ORR). The physical properties of the resultant catalysts were characterized using nitrogen adsorption measurements, X‐ray diffraction, Raman and X‐ray photoelectron spectroscopies and transmission electron microscopy. Subsequently, ORR activities of the catalysts were determined electrochemically using a conventional three‐electrode cell via cyclic voltammetry with a rotating disc electrode, the results of which indicated that the synthesized catalysts had a marked electrocatalytic activity towards ORR in acid media. Among the synthesized catalysts, that functionalized using 2,4,6‐tris(2‐pyridyl)‐1,3,5‐triazine as nitrogen source had the highest electrocatalytic activity with the highest onset potential (0.98 V/SHE) and limiting current density (5.12 mA cm−2). The findings are particularly important to determine a non‐precious metal catalyst for ORR activity in fuel cells.  相似文献   

12.
以4-硝基对苯腈,氨水和铜盐反应于在原位水热条件下合成了二(2,4-二(对硝基苯)-1,3,5-环戊二烯铜配合物,通过单晶X射线衍射,元素分析,红外,核磁光谱和热重分析等手段对其进行了表征。结构分析表明,铜与四个源自原位合成的配体上的氮原子配位形成平面四边形构型。基于密度泛函的理论计算对配合物的热力学稳定性进行了阐释。  相似文献   

13.
A new cadmium (II) coordination polymer, [Cd(TTTMB)2]‐(SO4) · 21H2O, where TTTMB =1,3, 5‐tris (imidazol‐1‐yl‐methyl)‐2,4,6‐trimethylbenzene, was obtained by self‐assembly of tripodal ligand TTTMB with CdSO4·2.7H2O in acetonitrile, and characterized by X‐ray crystallography. The crystal data belongs to monoclinic space group Cc with cell parameters a = 1.16891(4) nm, b=2.06671(6) nm, c = 2.48185(7) nm, β = 97.8560(10)°, R = 0.0487, wR = 0.1211. The results of structure analysis indicate that each TTTMB ligand coordinates three metal atoms and in turn each Cd(II) atom with octahedral coordination geometry connects six nitrogen atoms of imidazole group from six different TTTMB ligands to produce a 2D honeycomb network structure. There are a lot of water molecules linked by hydrogen bonds and occupied the channels formed intra‐ and inter‐sheets.  相似文献   

14.
A structural rationale was adopted to design a series of metallogels from a newly synthesized urea‐functionalized dicarboxylate ligand, namely, 5‐[3‐(pyridin‐3‐yl)ureido]isophthalic acid ( PUIA ), that produces metallogels upon reaction with various metal salts (CuII, ZnII, CoII, CdII, and NiII salts) at room temperature. The gels were characterized by dynamic rheology and transmission electron microscopy (TEM). The existence of a coordination bond in the gel state was probed by FTIR and 1H NMR spectroscopy in a ZnII metallogel (i.e., MG2 ). Single crystals isolated from the reaction mixture of PUIA and CoII or CdII salts characterized by X‐ray diffraction revealed lattice inclusion of solvent molecules, which was in agreement with the hypothesis based on which the metallogels were designed. MG2 displayed anti‐inflammatory response (prostaglandin E2 assay) in the macrophage cell line (RAW 264.7) and anticancer properties (cell migration assay) on a highly aggressive human breast cancer cell line (MDA‐MB‐231). The MG2 metallogel matrix could also be used to load and release (pH responsive) the anticancer drug doxorubicin. Fluorescence imaging of MDA‐MB‐231 cells treated with MG2 revealed that it was successfully internalized.  相似文献   

15.
[Pb(trz)(tfpb)(H2O)] ( 1 ) (trz and tfpb are the abbreviations of 2,4,6‐tris(2‐pyridyl)‐1,3,5‐triazine and 4,4,4‐trifluoro‐1‐phenyl‐1,3‐butandionate, respectively) have been synthesized and characterized by elemental analysis and IR, 1H NMR, spectroscopy. The single‐crystal structure of 1 shows the coordination number of the Pb2+ ions is eight with three N‐donor atoms from a “trz” ligand and four O‐donors from the dionate ligand and one molecule of water. The supramolecular features in this complex are guided by lone pair activity and control of strong hydrogen bonds, weak directional intermolecular interactions and aromatic π‐π stacking interactions.  相似文献   

16.
Two new silver(I) 3D coordination polymers, namely [Ag3(2‐stp)(dpa)]n ( 1 ) and {[Ag2(2‐stp)(H2O)]?Hdpa}n ( 2 ) (2‐NaH2stp=sodium 2,5‐dicarboxysulfonate, dpa=di(pyridine‐2‐yl)amine) were synthesized. The complexes were characterized by elemental analysis, FT‐IR spectra, thermogravimetric analyses (TGA), and single‐crystal X‐ray diffraction. In complex 1 , three neighboring Ag ions are bridged by N‐ and O‐atom, forming a 3D coordination network. The molecular structure of 2 is cation? anion species, forming 3D host? guest supramolecular network with the [Hdpa]+ cations encapsulated in the nanochannels. The photoluminescence properties of the complexes were also investigated in the solid state at room temperature.  相似文献   

17.
Two novel lanthanide coordination polymers, [La(tpaa)3(H2O)2] ( 1 ) and [Eu2(BDC)3(DMF)2(H2O)2] ( 2 ) (Htpaa = terephthalamic acid, H2BDC = 1,4‐benzenedicarboxylic acid, DMF = N,N‐dimethylformamide), were hydro(solvo)thermally synthesized by reactions of the corresponding lanthanide nitrate salts with 1,3,5‐triazine‐2,4,6‐tri(4‐benzenecarboxylate) ( L ), in which a simultaneous hydrolysis of the ligand L occurred. Single‐crystal X‐ray analysis revealed that complex 1 comprises one‐dimensional chains that are further interlinked via hydrogen bonds, resulting in a two‐dimensional network; while complex 2 is a three‐dimensional interpenetrated coordination architecture.  相似文献   

18.
Nanostructures of a new coordination polymer of divalent lead with the ligand 2, 9‐dimethyl‐1, 10‐phenanthroline (dmp) containing the first Pb2‐(μ‐ClO4)2 motif, [Pb2(dmp)2(μ‐N3)2(μ‐ClO4)2]n ( 1 ), was synthesized by a sonochemical method that produces the coordination polymers at nano size. The new nanostructure was characterized by scanning electron microscopy, X‐ray powder diffraction, IR, 1H NMR and 13C NMR spectroscopy, and elemental analysis. Compound 1 was structurally characterized by single‐crystal X‐ray diffraction and the single‐crystal X‐ray data shows that the coordination number of PbII ions is six, (PbN4O2), with two N‐donor atoms from aza‐aromatic base ligands and four O‐donors from two perchlorate anions and two N‐donors from two azide anions. It has a “stereo‐chemically active” electron lone pair, and the coordination sphere is hemidirected. The supramolecular features in these complexes are guided and controlled by weak directional intermolecular interactions. The chains interact with each other through π–π stacking interactions creating a 3D framework. The structure of the title complex was optimized by density functional theory calculations. Calculated structural parameters and IR spectra for the title complex are in agreement with the crystal structure. The PbO nanoparticles were obtained by thermolysis of 1 at 180 °C with oleic acid as a surfactant. The average diameter of the nanoparticles was estimated by the Scherrer equation to be 23 nm. The morphology and size of the prepared PbO samples were further observed using SEM.  相似文献   

19.
The metal complexes [Hg2(tbim)2Br4]·2DMF ( 1 ) and [Hg2(tbim)I4]·1.5DMF ( 2 ) were prepared by reactions of 1,3,5‐tris(benzimidazol‐1‐ylmethyl)‐2,4,6‐trimethylbenzene (tbim) with HgBr2, HgI2, respectively, and [Hg2(tbim)I4]·0.5(FeCp2)·H2O ( 3 ) was obtained by the same method with addition of ferrocene (FeCp2) as additive. Their structures were determined by X‐ray crystallographic analyses. Complex 1 has a macrocyclic binuclear structure with one benzimidazole arm of the ligand free of coordination and the binuclear units are further connected by C‐H···N hydrogen bonds to give an infinite zigzag chain. Complexes 2 and 3 have a 2D network structure in which tbim serves as a tridentate ligand. The results showed that the halides of bromide and iodide have remarkable impact on the structure of the complexes. The FeCp2 molecules are trapped in the voids of framework 3 .  相似文献   

20.
Three tripodal ligands H3L1–3 containing imidazole rings were synthesized by the reaction of 1,10‐phenanthroline‐5,6‐dione with 1,3,5‐tris[(3‐formylphenoxy)methyl]benzene, 1,3,5‐tris[(3‐formylphenoxy)methyl]‐2,4,6‐trimethylbenzene, and 2,2′,2"‐tris[(3‐formylphenoxy)ethyl]amine, respectively. Trinuclear RuII polypyridyl complexes [(bpy)6Ru3H3L1–3](PF6)6 were prepared by the condensation of Ru(bpy)2Cl2 · 2H2O with ligands H3L1–3. The pH effects on the UV/Vis absorption and fluorescence spectra of the three complexes were studied, and ground‐ and excited‐state ionization constants of the three complexes were derived. The three complexes act as “off‐on‐off” fluorescence pH switch through protonation and deprotonation of imidazole ring with a maximum on‐off ratio of 5 in buffer solution at room temperature.  相似文献   

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