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1.
In the current work, two triazine‐based multidentate ligands (H2L1 and H2L2) and their homo‐dinuclear Mn (II), mononuclear Ln (III) and hetero‐dinuclear Mn (II)/Ln (III) (Where Ln: Eu or La) complexes were synthesized and characterized by spectroscopic and analytical methods. Single crystals of a homo‐dinuclear Mn (II) complex {[Mn (HL1)(CH3OH)](ClO4·CH3OH}2 ( 1 ) were obtained and the molecular structure was determined by X‐ray diffraction method. In the structure of the complex, each Mn (II) ion is seven‐coordinate and one of the phenolic oxygen bridges two Mn (II) centre forming a dimeric structure. The UV–Vis. and photoluminescence properties of synthesized ligands and their metal complexes were investigated in DMF solution and the compounds showed emission bands in the UV–Vis. region. The catecholase enzyme‐like activity of the complexes were studied for 3,5‐DTBC → 3,5‐DTBQ conversion in the presence of air oxygen. Homo‐dinuclear Mn (II) complexes ( 1 and 4 ) were found to efficiently catalyse 3,5‐DTBC → 3,5‐DTBQ conversion with the turnover numbers of 37.25 and 35.78 h?1 (kcat), respectively. Mononuclear Eu (III) and La (III) complexes did not show catecholase activity.  相似文献   

2.
Two new metal complexes [Zn( L1 )]n ( 1 ) and [Cd3( L2 )2Cl2(H2O)6]n ( 2 ) (H2 L1 = 1,5‐bis(tetrazol‐5‐yl)‐3‐oxapentane, H2 L2 = bis(tetrazol‐5‐yl)methane) have been synthesized and characterized by elemental analysis, IR spectroscopy and single‐crystal X‐ray diffraction analysis. Complex 1 was a 2‐D sheet constructed by L1 and Zn(II) center, further assembled to form a three‐dimensional (3‐D) supramolecular networks through weak hydrogen‐bonding interactions. In the complex 2 , there were two unequivalent Cd(II) centers, and some of ligands L2 adopted chelate coordination mode, and others adopted bridge coordination mode linking the Cd1 center and simultaneously bridging the Cd2 center, the Cl anions adopted μ2 bridging mode, ligands L2 and the Cl anions linked the Cd(II) centers to form a 3‐D supramolecular networks.  相似文献   

3.
Three novel zinc complexes [Zn(dbsf)(H2O)2] ( 1 ), [Zn(dbsf)(2,2′‐bpy)(H2O)]·(i‐C3H7OH) ( 2 ) and [Zn(dbsf)(DMF)] ( 3 ) (H2dbsf = 4,4′‐dicarboxybiphenyl sulfone, 2,2′‐bpy = 2,2′‐bipyridine, i‐C3H7OH = iso‐propanol, DMF = N,N‐dimethylformamide) were first obtained and characterized by single crystal X‐ray crystallography. Although the results show that all the complexes 1–3 have one‐dimensional chains formed via coordination bonds, unique three‐dimensional supramolecular structures are formed due to different coordination modes and configuration of the dbsf2? ligand, hydrogen bonds and π–π interactions. Iso‐propanol molecules are in open channels of 2 while larger empty channels are formed in 3 . As compared with emission band of the free H2dbsf ligand, emission peaks of the complexes 1–3 are red‐shifted, and they show blue emission, which originates from enlarging conjugation upon coordination. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

4.
The reactions of cobalt acetates with tetrachloroterephthalic acid (H2BDC‐Cl4) in different solvents gave two polymeric and one mononuclear CoII complexes. X‐ray single‐crystal structural determination revealed that the ligand BDC‐Cl4 displays a reliable bridging tecton to construct diverse supramolecular architectures through coordinative bonds or secondary hydrogen‐bonding interactions. The complexes [Co(BDC‐Cl4)(DMF)2(EtOH)2]n ( 1 ) and {[Co(BDC‐Cl4)(DMF)2(MeOH)2] · 2DMF}n ( 2 ) demonstrate a one‐dimensional (1D) coordination motif with infinite CoII‐tetrachloroterephthalate chains, which are tuned by different binding solvent systems of DMF/ethanol (EtOH) and DMF/methanol (MeOH). [Co(DMF)2(H2O)4] · (BDC‐Cl4) ( 3 ) represents a two‐dimensional (2D) metallosupramolecular network by hydrogen‐bonded bridging between the aqua ligand of the mononuclear complex with the uncoordinated BDC‐Cl4 solvates. The spectroscopic, thermal, and fluorescent properties of 1 – 3 were also investigated.  相似文献   

5.
Naphthaldimines containing N2O2 donor centers react with platinum(II) and (IV) chlorides to give two types of complexes depending on the valence of the platinum ion. For [Pt(II)], the ligand is neutral, [(H2L1)PtCl2]·3H2O (1) and [(H2L3)2Pt2Cl4]·5H2O (3), or monobasic [(HL2)2Pt2Cl2]·2H2O (2) and [(HL4)2Pt]·2H2O (4). These complexes are all diamagnetic having square-planar geometry. For [Pt(IV)], the ligand is dibasic, [(L1)Pt2Cl4(OH)2]·2H2O (5), [(L2)Pt3Cl10]·3H2O (6), [(L3)Pt2Cl4(OH)2]·C2H5OH (7) and [(L4)Pt2Cl6]·H2O (8). The Pt(IV) complexes are diamagnetic and exhibit octahedral configuration around the platinum ion. The complexes were characterized by elemental analysis, UV-Vis and IR spectra, electrical conductivity and thermal analyses (DTA and TGA). The molar conductances in DMF solutions indicate that the complexes are non-ionic. The complexes were tested for their catalytic activities towards cathodic reduction of oxygen.  相似文献   

6.
In the present work a new ligand, 2-(2-(phenyl(pyridin-2-yl)methyleneamino)ethylamino)ethanol (L), and its Zn(II) and Cd(II) complexes, [Zn(L)Br2] (1), [Cd(L)Br2] (2) and [Cd(L)I2] (3), have been synthesized and characterized by elemental analysis, FT-IR, Raman and 1H NMR spectroscopies as well as X-ray crystallography. All complexes are isostructural and their metal ions have distorted square pyramidal geometry with an MN3X2 (X: Br, I) environment. During the complexation process, the amine group of the ligand becomes a chiral center. In the solid-state, an R-configuration was observed in all three complexes. Furthermore, the molecules form intermolecular C–H?O, C–H?X and O–H?X (X: Br, I) hydrogen bonds in the solid-state.  相似文献   

7.
A tetradentate N-donor ligand 1,4-bis[2-(2-pyridyl)benzimidazolato]butane (L) was prepared for construction of a coordination framework. Three one-dimensional coordination polymers {[M(II)L(NCS)2](DMF)2} n (M(II) = cadmium(II), 1, zinc(II), 2, manganese(II), 3) were obtained by reaction of metal ions and L in the presence of KSCN in DMF/water. The complexes are isostructural and consist of 1D zigzag [M(II)L(NCS)2] n chains and DMF molecules. Within the chains, the metal atoms are each octahedrally coordinated by four N atoms of L and two N atoms of the SCN? anions. Complexes 1 and 2 in the solid state at room temperature exhibit intense photoluminescence at 453 and 433 nm, respectively.  相似文献   

8.
The reaction of N‐(2‐pyridyl)carbonylaniline (L) with Zn(NO3)2, CdCl2, and Hg(SCN)2 gives the following complexes: [Zn(L)2](NO3)2, [Cd(L)2Cl2], and [Hg(L)(SCN)2]. The new complexes were characterized by elemental analyses and IR‐, 1H‐, 13C‐NMR spectroscopy. The crystal structure of the [Hg(L)(SCN)2] was determined by single crystal X‐ray analysis. The monomeric complex is built up of a Hg(SCN)2 unit with one N‐(2‐pyridyl)carbonylaniline (L) ligand coordinated to the Hg atom via the ring pyridinic nitrogen atom and the carbonyl oxygen atom forming a five‐membered chelate ring. The Hg atom has a distorted tetrahedral environment. There is π‐π stacking interaction between the parallel aromatic rings belonging to adjacent chain as planar species in which the mean molecular planes are close to parallel and separated by a distance of ~ 3.5Å, close to that of the planes in graphite. The coordinated N‐(2‐pyridyl)carbonylaniline (L) molecule is involved in hydrogen bonding acting as hydrogen‐bond donors with S and N atoms from SCN ligand as potential hydrogen‐bond acceptors. There is a shortest intermolecular contacts between the S and N atoms. The hydrogen bonding and shortest intermolecular contacts between the S and N atoms yields infinite chains parallel to the crystallographic vector c. Each molecule is bonded to two neighbors.  相似文献   

9.
Two new usymmetric bidentate Schiff-base ligands (2-pyridyl-2-furylmethyl)imine (L1) and (2-pyridyl-phenylmethyl)imine (L2) were prepared. The crystal structures of two chloro-bridged complexes [Cu2(μ-Cl)2(L1)2Cl2] (1) and [Mn (μ-Cl)2(L2)] (2) derived from the each ligand have been confirmed by single-crystal X-ray diffraction analysis. The complexes were characterized by IR, elemental analysis and spectroscopic methods. In complex 1, the two copper atoms are five-coordinate involving a square-pyramidal geometry having a N2Cl3 donor set with the two chlorine atoms bridging the two copper atoms. In complex 2, the manganese atoms are both six-coordinate. In contrast to 1, all chlorine atoms in 2 are bridging chlorides and link adjacent manganese atoms together forming 1-D infinite chains.  相似文献   

10.
Binuclear and tetranuclear copper(II) complexes are of interest because of their structural, magnetic and photoluminescence properties. Of the several important configurations of tetranuclear copper(II) complexes, there are limited reports on the crystal structures and solid‐state photoluminescence properties of `stepped' tetranuclear copper(II) complexes. A new CuII complex, namely bis{μ3‐3‐[(4‐methoxy‐2‐oxidobenzylidene)amino]propanolato}bis{μ2‐3‐[(4‐methoxy‐2‐oxidobenzylidene)amino]propanolato}tetracopper(II), [Cu4(C11H13NO3)4], has been synthesized and characterized using elemental analysis, FT–IR, solid‐state UV–Vis spectroscopy and single‐crystal X‐ray diffraction. The crystal structure determination shows that the complex is a stepped tetranuclear structure consisting of two dinuclear [Cu2(L )2] units {L is 3‐[(4‐methoxy‐2‐oxidobenzylidene)amino]propanolate}. The two terminal CuII atoms are four‐coordinated in square‐planar environments, while the two central CuII atoms are five‐coordinated in square‐pyramidal environments. The solid‐state photoluminescence properties of both the complex and 3‐[(2‐hydroxy‐4‐methoxybenzylidene)amino]propanol (H2L ) have been investigated at room temperature in the visible region. When the complex and H2L are excited under UV light at 349 nm, the complex displays a strong blue emission at 469 nm and H2L displays a green emission at 515 nm.  相似文献   

11.
The reactions of pyrimidine‐phosphine ligand N‐[(diphenylphosphino)methyl]‐2‐pyrimidinamine ( L ) with various metal salts of PtII, PdII and CuI provide three new halide metal complexes, Pt2Cl4(μ‐L)2·2CH2Cl2 ( 1 ), Pd2Cl4(μ‐L)2 ( 2 ), and [Cu2(μ‐I)2L2]n ( 3 ). Single crystal X‐ray diffraction studies show that complexes 1 and 2 display a similar bimetallic twelve‐membered ring structure, while complex 3 consists of one‐dimensional polymeric chains, which are further connected into a 2‐D supramolecular framework through hydrogen bonds. In the binuclear complexes 1 and 2 , the ligand L serves as a bridge with the N and P as coordination atoms, but in the polymeric complex 3 , both bridging and chelating modes are adopted by the ligand. The spectroscopic properties of complexes 1 ‐ 3 as well as L have been investigated, in which complex 3 exhibits intense photoluminescence originating from intraligand charge transfer (ILCT) π→π* and metal‐to‐ligand charge‐transfer (MLCT) excited states both in acetonitrile solution and solid state, respectively.  相似文献   

12.
In order to screen effective fungicides, three Zn (II) complexes, [Zn L 1 4 (NO3)2]·2H2O·2EtOH ( 1 ), [Zn L 2 4 (NO3)2] ( 2 ), and [Zn L 3 4 (DMF)2](NO3)2 ( 3 ), ( L 1  = paclobutrazol, L 2  = diniconazole, and L 3  = hexaconazole), were synthesized and characterized by elemental analysis, FT‐IR spectroscopy, and single‐crystal XRD. The antifungal activities of these complexes were then evaluated against four selected fungi using the mycelial growth rate method. The resulting data indicate that all the complexes show the enhanced antifungal activities than the corresponding ligand and mixtures. And, the interactions between the metal salt and ligands in the three complexes seem to be synergistic. According to the study of the influence of the structures on the activity, complex 2 with C=C linkage and 2,4‐dichlorophenyl moieties enhances the bioactivity significantly, especially against Wheat gibberellic ( II ). Density functional theory (DFT) calculations were carried out to help explain the enhanced bioactivity of the Zn (II) complexes. Meanwhile, all complexes are excellent grow‐regulators, especially complex 3 . The resulting data show that the complexes based on triazole fungicides have the potential applications in agriculture.  相似文献   

13.
Based on the a ligand BDPPZ [(9a,13a‐dihydro‐4,5,9,14‐tetraaza‐benzo[b]triphenylene‐11‐yl)‐phenyl‐methanone] (1) and its polypyridyl hetero‐ and homoleptic Ru(II) metal complexes, [Ru(bpy)2L](PF6)2 (2), [Ru(phen)2L](PF6)2 (3), [Ru(dafo)2L](PF6)2 (4), [Ru(dcbpy)2L](PF6)2 (5) and [RuL3](PF6)2 (6) (where, L = ligand, bpy = 2,2′‐bipyridine, phen = 1,10‐phenantroline, dafo = 4,5‐diazafluoren‐9‐one and dcbpy = 3,3′‐dicarboxy‐2,2′‐bipyridine), have been synthesized and characterized by elemental analysis, UV–vis, FT‐IR, 1H and 13C‐NMR spectra (for ligand), molar conductivity measurements and X‐ray powder techniques. The electrochemical parameters of the substituted ligand and its polypyridyl hetero‐ and homoleptic Ru(II) metal complexes are reported by cyclic voltammetry. UV–vis spectroscopy is used to compare the differences between the conjugated π systems in this ligand and its Ru(II) metal complexes. The polypyridyl hetero‐ and homoleptic Ru(II) metal complexes also tested as catalysts for the formation of cyclic organic carbonates from carbon dioxide and liquid epoxides which served as both reactant and solvent. The results showed that the [Ru(L)3](PF6)2 (6) complex is more efficient than the other Ru(II) complexes for the formation of cyclic organic carbonates from carbon dioxide. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

14.
The novel mixed ligand complexes [M(bpy)(phen-dione)](PF6)2 (M?=?Zn(II), Cd(II) and Hg(II), bpy?=?2,2-bipyridine and phen-dione?=?1,10-phenanthroline-5,6-dione) have been synthesized and characterized by elemental analysis, IR, 1H NMR and electronic absorption spectroscopies. The ν(C=O) of coordinated phen-dione in these complexes are very similar to the free phen-dione ligand showing that phen-dione is not coordinated to metal ion from its C=O sites. Absorption spectra of the complexes show two absorption bands for intraligand transitions. These absorption bands show dependence to the dielectric constant of solvent. These complexes exhibit an intensive fluorescence band around 535?nm in DMF when the excitation wavelength is 260?nm at room temperature. The fluorescence intensity of these complexes is larger than that of the free ligand.  相似文献   

15.
Five coordination compounds Zn(mbmpbi)2Cl2 (1), Zn(mbmpbi)2Br2 (2), Cd(mbmpbi)2Cl2 (3), Hg(mbmpbi)2Cl2 (4) and Hg(mbmpbi)2Br2 (5) were synthesized by the reaction of 1-(p-methoxybenzyl)-2-(p-methoxyphenyl)benzimidazole (mbmpbi) with the corresponding metal halides. The complexes have been characterized by elemental analysis, conductance measurements, FT-IR, 1H NMR and photoluminescence spectral studies. The ligand mbmpbi exhibits the N-benzimidazole coordination. The structures of 3-5 have been determined by single crystal X-ray diffraction. These three complexes are isostructural, crystallizing in the monoclinic system, P2/n space group with a distorted tetrahedral geometry around the metal ion. Zn(II) and Cd(II) complexes show strong blue emission in solid state at room temperature.  相似文献   

16.
Varying coordination modes of the Schiff base ligand H2L [5-methyl-1-H-pyrazole-3-carboxylic acid (1-pyridin-2-yl-ethylidene)-hydrazide] towards different metal centers are reported with the syntheses and characterization of four mononuclear Mn(II), Co(II), Cd(II) and Zn(II) complexes, [Mn(H2L)(H2O)2](ClO4)2(MeOH) (1), [Co(H2L)(NCS)2] (2), [Cd(H2L)(H2O)2](ClO4)2 (3) and [Zn(H2L)(H2O)2](ClO4)2 (4), and a binuclear Cu(II) complex, [Cu2(L)2](ClO4)2 (5). In the complexes 1-4 the neutral ligand serves as a 3N,2O donor where the pyridine ring N, two azomethine N and two carbohydrazine oxygen atoms are coordinatively active, leaving the pyrazole-N atoms inactive. In the case of complex 5, each ligand molecule behaves as a 4N,O donor utilizing the pyridine N, one azomethine N, the nitrogen atom proximal to the azomethine of the remaining pendant arm and one pyrazole-N atom to one metal center and the carbohydrazide oxygen atom to the second metal center. The complexes 1-4 are pentagonal bipyramidal in geometry. In each case, the ligand molecule spans the equatorial plane while the apical positions are occupied by water molecules in 1, 3 and 4 and two N bonded thiocyanate ions in 2. In complex 5, the two Cu(II) centers have almost square pyramidal geometry (τ = 0.05 for Cu1 and 0.013 for Cu2). Four N atoms from a ligand molecule form the basal plane and the carbohydrazide oxygen atom of a second ligand molecule sits in the apex of the square pyramid. All the complexes have been X-ray crystallographically characterized. The Zn(II) and Cd(II) complexes show considerable fluorescence emission while the remaining complexes and the ligand molecule are fluorescent silent.  相似文献   

17.
An asymmetric bidentate Schiff-base ligand (2-hydroxybenzyl-2-furylmethyl)imine (L–OH) was prepared. Three complexes derived from L–OH were synthesized by treating an ethanolic solution of the appropriate ligand with an equimolar amount of metallic salt. Three complexes, Cu2(L–O?)2Cl2 (1), Ni(L–O?)2 (2) and Co(L–O?)3 (3), have been structurally characterized through elemental analysis, IR, UV spectra and thermogravimetric analysis. Single crystal X-ray diffraction shows metal ions and ligands reacted with different proportions 1?:?1, 1?:?2 and 1?:?3, respectively, so copper(II), nickel(II), and cobalt(III) have different geometries.  相似文献   

18.
New palladium(II) complexes, [Pd(PPh3)L] ( 2 ) and [Pd(AsPh3)L] ( 3 ), were synthesized using 4‐hydroxybenzoic acid (3‐ethoxy‐2‐hydroxybenzylidene)hydrazide ( 1 ) ligand (H2L), and characterized using various physicochemical techniques. The molecular structures of 2 and 3 were determined using single‐crystal X‐ray diffraction, which reveals a square planar geometry around the palladium(II) metal ion. In vitro DNA binding studies were conducted using UV–visible absorption spectroscopy, emission spectroscopy, cyclic voltammetry and viscosity measurements, which suggest that the metal complexes act as efficient DNA binders. The interaction of ligand H2L and complexes 2 and 3 with bovine serum albumin (BSA) was investigated using UV–visible and fluorescence spectroscopies. Absorption and emission spectral studies indicate that complexes 2 and 3 interact with BSA protein more strongly than the parent ligand. The free radical scavenging potential of all the synthesised compounds ( 1 – 3 ) was also investigated under in vitro conditions. In addition, the in vitro cytotoxicity of the complexes to tumour cells lines (HeLa and MCF‐7) was examined using the MTT assay method.  相似文献   

19.
A two‐dimensional MnII coordination polymer (CP), poly[bis[μ2‐2,6‐bis(imidazol‐1‐yl)pyridine‐κ2N3:N3′]bis(thiocyanato‐κN)manganese] [Mn(NCS)2(C11H9N5)2]n, (I), has been obtained by the self‐assembly reaction of Mn(ClO4)2·6H2O, NH4SCN and bent 2,6‐bis(imidazol‐1‐yl)pyridine (2,6‐bip). CP (I) was characterized by FT–IR spectroscopy, elemental analysis and single‐crystal X‐ray diffraction. The crystal structure features a unique two‐dimensional (4,4) network with one‐dimensional channels. The luminescence and nitrobenzene‐sensing properties were explored in a DMF suspension, revealing that CP (I) shows a strong luminescence emission and is highly sensitive for nitrobenzene detection.  相似文献   

20.
Copper(II)–Schiff base complexes have attracted extensive interest due to their structural, electronic, magnetic and luminescence properties. The title novel monomeric CuII complex, [Cu(C10H11N2O4)2], has been synthesized by the reaction of 3‐{[(3‐hydroxypropyl)imino]methyl}‐4‐nitrophenol (H2L ) and copper(II) acetate monohydrate in methanol, and was characterized by elemental analysis, UV and IR spectroscopies, single‐crystal X‐ray diffraction analysis and a photoluminescence study. The CuII atom is located on a centre of inversion and is coordinated by two imine N atoms, two phenoxy O atoms in a mutual trans disposition and two hydroxy O atoms in axial positions, forming an elongated octahedral geometry. In the crystal, intermolecular O—H…O hydrogen bonds link the molecules to form a one‐dimensional chain structure and π–π contacts also connect the molecules to form a three‐dimensional structure. The solid‐state photoluminescence properties of the complex and free H2L have been investigated at room temperature in the visible region. When the complex and H2L are excited under UV light at 349 nm, the complex displays a strong green emission at 520 nm and H2L displays a blue emission at 480 nm.  相似文献   

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