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1.
The reaction of 4-methyl-3,5-di(2-pyridyl)-4H-1,2,4-triazole (medpt) with Zn(ClO4)2·6H2O and NaSCN, NaN3 or NaNO2 in a 2:1:1 molar ratio in MeOH/H2O (9:1) affords the mononuclear complexes [ZnII(medpt)2(NCS)]ClO4, [ZnII(medpt)2(N3)]ClO4 and [ZnII(medpt)2(NO2)]ClO4, respectively. All three complexes have been structurally characterised and found to feature unusual coordination polyhedra for 3,5-di(2-pyridyl)-4H-1,2,4-triazole complexes. In [ZnII(medpt)2(NCS)]ClO4 and [ZnII(medpt)2(N3)]ClO4, the zinc atom resides within a distorted square-pyramidal N5 coordination sphere [τ = 0.22 and 0.04, respectively] with two bidentate medpt ligands bound equatorially and the pseudohalide ion coordinating as a unidentate co-ligand in the apical position. In contrast, the NO2 ion in [ZnII(medpt)2(NO2)]ClO4 acts as a bidentate ligand, which leads to a strongly distorted N4O2 coordination environment about the metal centre.  相似文献   

2.
Four 3d–4f heteronuclear complexes, [(ZnL)2La(OAc)2]·ClO4·2CHCl3 (1), [(ZnL)2La(OAc)2]·CF3SO3·H2O (2), [ZnNd(L)(Py)(NO3)3] (3), and [ZnGd(L)(OAc)(NO3)2] (4) (Py = pyridine; H2L = 6,6′-dimethoxy-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol), have been prepared by one-pot reaction of H2L with zinc(II) acetate, lanthanide(III) ions and Py. Although the heterobinuclear complexes 14 are prepared in the same reaction condition, the Py does not coordinate to Zn(II) of 1, 2, and 4. Instead, the bridging μ-acetato ligand is present. The coordination of the Py in 3 leads to smaller distortion of square pyramidal coordination site of Zn(II), the higher coplanarity between the planes of ZnO(phenoxo)2 and LnO(phenoxo)2, and the longer Zn?Ln distance compared with 4. The luminescence properties of 14 have been discussed. The ligand (L2?) can sensitize NIR luminescence of Nd(III) ions.  相似文献   

3.
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   

4.
Six transition metal coordination compounds with H2mand and different N-donor ligands, [Co(Hmand)2(2,2′-bipy)]·H2O (1), [Ni(Hmand)2(2,2′-bipy)]·H2O (2), [Ni(Hmand)2(bpe)] (3), [Zn(Hmand)2(2,4′-bipy)(H2O)]·2H2O (4), [Zn(Hmand)(bpe)(H2O)]n[(ClO4)]n·nH2O (5), and [Zn(Hmand)(4,4′-bipy)(H2O)]n[(ClO4)]n (6), were synthesized under different conditions (H2mand = (S)-(+)-mandelic acid, bpe = 1,2-di(4-pyridyl)ethane, 4,4′-bipy = 4,4′-bipyridine, 2,4′-bipy = 2,4′-bipyridine, 2,2′-bipy = 2,2′-bipyridine). Their structures were determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, infrared spectra, thermogravimetric analysis, powder X-ray diffraction, and circular dichroism. Compounds 1 and 2 are isostructural (0-D structures), which are extended to supramolecular 1-D chains by hydrogen bonding. Compound 3 exhibits 1-D straight chain structures, which are further linked via hydrogen bond interactions to generate a 3-D supramolecular architecture. Compound 4 displays a discrete molecular unit. Neighboring units are further linked by hydrogen bonds and ππ interactions to form a 3-D supramolecular architecture. Compound 5 displays a 2-D undulated network, further extended into a 3-D supramolecular architecture through hydrogen bond interactions. Compound 6 possesses a 2-D sheet structure. Auxiliary ligands and counteranions play an important role in the formation of final frameworks, and the hydrogen-bonding interactions and ππ stacking interactions contributed to the formation of the diverse supramolecular architectures. Compounds 1, 2, 4, 5, and 6 crystallize in chiral space groups, with the circular dichroism spectra exhibiting positive cotton effects. Furthermore, the luminescent properties of 46 have been examined in the solid state at room temperature, and the different crystal structures influence emission spectra significantly.  相似文献   

5.
A new series of complexes of transition metal (Cu, Zn, Ni) perchlorate with imidazole have been synthesized and characterized by elemental analysis, infrared (IR), UV-Vis spectroscopy, and single-crystal X-ray diffraction. Based on elemental and spectral data, the complexes are M(C3H4N2) x (ClO4)2 (M?=?Cu, Zn, x?=?4; M?=?Ni, x?=?6; C3H4N2?=?imidazole). The crystal structures of Cu(C3H4N2)4(ClO4)2 (1) and Zn(C3H4N2)4(ClO4)2 (2) show metals surrounded by four nitrogens of imidazole, while the nickel complex Ni(C3H4N2)6(ClO4)2 (3) has six nitrogens of imidazole. Intra- and inter-molecular hydrogen bonds exist between hydrogen of imidazole and oxygen of perchlorate. The thermal stabilities of 1, 2, and 3 at different heating rates (β?=?5°C?min?1, 10°C?min?1, and 15°C?min?1) show that all the complexes exhibit two thermal decomposition stages; the sequence of thermal stability is 2?>?1?>?3. 1, 2, 3, and imidazole display DNA binding ability, ascertained by UV-Vis titration.  相似文献   

6.
From 1-D to 3-D zinc coordination polymers based on multifunctional flexible 4-(1,2,4-triazole-methylene)-benzonitrile (tzbt), {[Zn(tzbt)2(bdc)]·2H2O}n (1), [Zn(tzbc)2]n (2), and [Zn(bpdc)(H2O)]n (3) (bdc = 1,4-benzenedicarboxylic acid, tzbc = 4-(1,2,4-triazole-methylene)-benzoic acid, bpdc = 4,4′-biphenyldicarboxylic acid), were synthesized under hydrothermal conditions. The tzbt was synthesized by N-alkylation and hydrolyzed in situ to produce tzbc (in 2). Single-crystal X-ray diffraction analysis reveals that 1 displays 1-D wave-like chains based on [Zn(bdc)]n. 2 is a chiral twofold interpenetrating 2-D architecture constructed with “V”-shaped tzbc. 3 is a 3-D chiral compound constructed from achiral H2bpdc with right-handed helical chains. 1–3 display stable blue-emitting luminescence with emission maxima ranging from 383 to 410 nm, depending on ligand-centered π*→π transitions. The effects of different polarity solvents and temperature on luminescence are discussed. TGA and VT-XPRD reveal that 2 has thermal stability to 360 °C.  相似文献   

7.
In the presence of nickel acetate, a chiral ligand, (S)-Hdphp ((S)-N-[di(2-pyridyl)-hydroxy-methyl]-proline), was synthesized in situ by nucleophilic addition of L-proline to di-2-pyridyl ketone. Based on this ligand, three chiral mononuclear complexes, {Ni[(S)-dphp](DMF)(H2O)}(ClO4) (1), {Ni[(S)-dphp](H2O)2}(ClO4)(H2O)1.5 (2), and {Ni[(S)-dphp](SCN)(H2O)} (3), have been obtained and characterized by single-crystal X-ray diffraction, elemental analyses, and infrared spectra. By virtue of charge-assisted O–H?···?O hydrogen-bonding interactions, all the complexes possess double chain structures. The double chains were connected into 2-D networks via π?···?π stacking and CH?···?π interactions in 1. For 2, O–H?···?O hydrogen-bonding interactions between free water molecules and other oxygens as well as π?···?π stacking and CH?···?π interactions extend the chains into a 3-D network. Complex 3 exhibits 3-D structure via O–H?···?S interactions.  相似文献   

8.
The reaction of ZnSiF6·6H2O with 4,4′-dipyridyldisulfide (4-PDS) in CH3OH afforded the complex [Zn(4-PDS)2(SiF6)·3CH3OH] n , 1, while the reaction of Zn(ClO4)2·6H2O with l,2-bis(4-pyridyl)ethane (bpa) in CH3OH gave the complex [Zn(bpa)2(ClO4)2·CH3OH] n , 2. The 4-DPS ligand in 1 is coordinated to the metal centers through both nitrogen atoms to form a 3-D open channel and the distorted octahedral coordination geometry at each zinc center is completed by a pair of trans-F-bonded hexafluorosilicate molecule. Compound 2, the channel-type 1-D chains are interlinked through C–H···O interaction to form 3-D structure with large cavities that are occupied by the methanol molecules.  相似文献   

9.
Two new zinc complexes, [Zn(Ppd)I]ClO4 (I) and [Zn(Ped)I]ClO4 (II), where Ppd and Ped are the Schiff bases N,N??-bis[(1-(2-pyridyl)ethylidene)propane-1,3-diamine and N,N??-bis[(1-(2-pyridyl)ethylidene)ethane-1,2-diamine, respectively, have been synthesized and characterized by means of elemental analysis, infrared spectroscopic, molar conductivity, and single crystal X-ray diffraction. The crystal of I is tri-clinic: space group $P\bar 1$ a = 8.421(2), b = 9.143(2), c = 13.166(3) ?, ?? = 92.521(5)°, ?? = 94.498(3)°, ?? = 94.232(4)°, V = 1006.6(4) ?3, Z = 2. The crystal of II is triclinic: space group $P\bar 1$ , a = 8.219(1), b = 8.483(1), c = 14.733(2) ?, ?? = 80.058(1)°, ?? = 81.960(1)°, ?? = 89.300(1)°, V = 1001.8(2) ?3, Z = 2. The zinc atom in the complexes assumes a distorted square pyramidal geometry through coordination by two pyridine N atoms and two imine N atoms of the Schiff base at the basal plane, and by a I atom at the apical position.  相似文献   

10.
The crystal structure of a novel dimeric zinc(II) complex, [ZnL(H2O)]2(ClO4)2·4H2O (L?=?N-(bis(2-pyridyl)methyl)-2-pyridinecarboxamide), has been determined by X-ray diffraction. In this complex each planar Npy–Namido–Npy moiety of the ligand coordinates to one zinc ion and the pendant pyridine of one [ZnL] unit completes the coordination sphere of a [ZnL] neighbor. Units of the complex are connected in a two-dimensional network by intermolecular hydrogen bonds. The thermodynamic properties of the ligand with bivalent metal ions Co(II), Ni(II), Cu(II) and Zn(II) were studied by potentiometric titration and the order of the stability constants is in agreement with the Irving–Williams series. The dimeric complex is stabilized through ligand sharing, as confirmed by the crystal structure and thermodynamic properties.  相似文献   

11.
Three copper(II), zinc(II), and vanadium(V) complexes, [CuL(HL)]ClO4 (1), [ZnL2] (2) and [VO2L] (3), where L is the anionic form of 3-methyl-N′-(1-(pyridin-2-yl)ethylidene)benzohydrazide (HL), were prepared and characterized by IR, UV–vis and single-crystal X-ray determination. X-ray analysis indicates that the complexes are mononuclear species, with the Cu and Zn ions in 1 and 2 in octahedral coordination, and with the V ion in 3 in trigonal bipyramidal coordination. The hydrazone compound and the three complexes were evaluated for antibacterial activities. The copper complex has effective activities.  相似文献   

12.
含二茂铁基的锌配合物的结构及其生物活性   总被引:1,自引:0,他引:1  
合成了4个含二茂铁基的锌配合物[Zn(FcCOO)(phen)2]ClO4·FcCOOH (1)(FcCOO=二茂铁甲酸根,phen=1,10-邻菲咯啉),[Zn(FcCOO)(phen)2]·ClO4·H2O (2),[Zn(FcCOO)(FcCOGly)(phen)]·C2H5OH (3)(FcCOGly=二茂铁甲酰化甘氨酸)和[Zn(FcCOGly)2(phen)]·CH3OH (4)。用X-射线单晶衍射测定了配合物的晶体结构。对4个配合物的生物活性进行了初步研究,发现配合物的抗菌活性与配合物的配位键强度及phen含量有一定的关系。  相似文献   

13.
Twelve oxamide-bridged Ln(III)–Cu(II) heteropentanuclear complexes Ln[Cu(PMoxd)]4(ClO4)3 · 5H2O (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, and PMoxd = the N,N′-Bi(α-pyridylmethyl)-oxamide dianion) and 12 oxamide-bridged Ln(III)–Cu(II) heteropentanuclear complexes with the formula of Ln[Cu(PEoxd)]4(ClO4)3 · 5H2O (PEoxd = the N,N′-Bi(α-pyridylethyl)-oxamide dianion) were synthesized and characterized. The magnetic properties of Gd[Cu(PMoxd)]4(ClO4)3 · 5H2O (7) and Gd[Cu(PEoxd)]4(ClO4)3 · 2H2O (19) show that there are ferromagnetic interactions between Gd(III) and Cu(II) in the complexes with J Cu–Gd = 1.38 cm?1 and J Cu–Gd = 1.00 cm?1, respectively. Fluorescent quenching phenomena for Eu[Cu(PMoxd)]4(ClO4)3 · 5H2O (6) and Tb[Cu(PMoxd)]4(ClO4)3 · 5H2O (8) were also observed.  相似文献   

14.
Two new Cu(II)–hydrazone complexes, [Cu(L)(Hbpe)ClO4]·ClO4·[Cu(L)Cl] (1) and [Cu(HL)2]·1.5ClO4·0.5OH (2) (where HL?=?(E)-N′-(1-(pyridine-2-yl)ethylidene)benzohydrazide and bpe = trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene), have been synthesized and characterized by physicochemical methods. The structures of the complexes have been established by single-crystal X-ray diffraction direct methods, which reveal that the metal ions have distorted square-pyramidal and square-planar geometries in 1, and a distorted octahedral geometry in 2. DNA binding of HL, 1, and 2, performed by UV–vis titration in tris-buffer medium, yielded binding constants, which are 9.5 × 103, 1.88 × 104, and 4.66 × 104 M?1, respectively. Viscosity measurements suggest a surface or groove-binding mode of interaction between CT-DNA with HL, 1, and 2.  相似文献   

15.
Reaction of the N-(2-pyridyl)carbonylaniline ligand (L) with Cu(NO3)2, Cu(ClO4)2, Zn(ClO4)2, Ni(NO3)2 and PdCl2 gives complexes with stoichiometry [Cu(L)2(H2O)2](NO3)2, [Cu(L)2(H2O)2](ClO4)2, [Zn(L)2(H2O)2] (ClO4)2, [Ni(L)2(H2O)Cl](NO3) and PdLCl2. The new complexes were characterized by elemental analyses and infrared spectra. The crystal structures of [Cu(L)2(H2O)2](NO3)2, [Cu(L)2(H2O)2](ClO4)2, and [Zn(L)2(H2O)2](ClO4)2 were determined by X-ray crystallography. The cation complexes [M(L)2(H2O)2] contain copper(II) and zinc(II) with distorted octahedral geometry with two N-(2-pyridyl)carbonylaniline (L) ligands occupying the equatorial sites. The hexa-coordinated metal atoms are bonded to two pyridinic nitrogens, two carbonyl oxygens and two water molecules occupying the axial sites. Both the coordinated water molecules and uncoordinated amide NH groups of the N-(2-pyridyl)carbonylaniline (L) ligands are involved in hydrogen bonding, resulting in infinite hydrogen-bonded chains running in one and two-dimensions.  相似文献   

16.
Reaction of N-(4-pyridyl)picolinamide (4-ppa), N-(4-pyridyl)nicotinamide (4-pna), N-(4-pyridyl)isonicotinamide (4-pina), and N-(2-pyridyl)isonicotinamide (2-pina) with divalent metal salts led to the formation of six new coordination complexes. The X-ray structure of [Zn(4-ppa)2Cl2] (1) shows a mononuclear structure with interesting intermolecular hydrogen bonding interactions. [Zn(4-pna)(OAc)2]n (2), Cu(4-pna)(OTf)2(DMF)2]n (3), {[Zn(4-pina)(DMF)4](OTf)2}n (4), {[Fe(4-pina)(DMF)4](OTf)2}n (5), and [Cu(2-pina)(OTf)2(DMF)2]n (6) are one-dimensional coordination polymers with conformational differences caused by the coordination donor disposition, which demonstrates the flexibility of the pyridylamide ligands in polymeric structures. Reflectance UV-visible spectra and thermal properties of the coordination polymers are also reported.  相似文献   

17.
Two pairs of isostructural transition metal coordination polymers, {[Co(L)(H2O)]n} (1) and {[Zn(L)(H2O)]n} (3), {[Co(L)(4,4′-bipy)(H2O)]·H2O}n (2) and {[Zn(L)(4,4′-bipy)(H2O)]·H2O}n (4) (H2L = N-pyrazinesulfonyl-glycine acid and 4,4′-bipy = 4,4′-bipyridine), have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental and thermogravimetric analyses. The structures show that 1 and 3 display 2-D polymeric grid frameworks with a 3-connected (4, 82) topology. 2 and 4 also exhibit a 2-D polymeric grid structure, but are constructed by a 4-connected (4, 4) topology. The adjacent 2-D polymeric grid frameworks for 1–4 are further linked by hydrogen bonding O–H?O interactions to form 3-D supramolecular interweaved orderly networks. The fluorescent properties of 3 and 4 were investigated in the solid state.  相似文献   

18.
Three Zn(II) complexes, [Zn2(bpp)2(FNA)2]·H2O (1), [Zn(bpp)(FNA)]·H2O (2), and Zn2(bpp)2(FNA)2 (3) (bpp = 1,3-bi(4-pyridyl)propane, H2FNA = 4-nitrobenzene-1,2-dicarboxylic acid), were synthesized and characterized by single-crystal and powder X-ray diffraction methods, IR spectroscopy, TG analyses, elemental analyses, and fluorescent analysis. In 1, the Zn(II) ions are linked by FNA anions and bpp into 2-D layers. The Zn(II) ions in 2 are bridged by FNA anions into chiral chains, which are interlinked by bpp into 3-D metal–organic framework with (65·8) CdS topology. Complex 3 features 1-D zigzag chains, which are interconnected by bpp ligands to give a 3-D framework with (6·74·8)(64·7·8) topology. Complexes 2 and 3 exhibit significant ferroelectric behavior (for 2 remnant polarization Pr = 0.050 μC cm?2, coercive field Ec = 1.13 kV cm?1, saturation of the spontaneous polarization Ps = 0.239 μC cm?2; for 3 Pr = 0.192 μC cm?2, Ec = 4.64 kV cm?1, Ps = 0.298 μC cm?2).  相似文献   

19.
New homoleptic zinc(II) complexes, [Zn(L)2], where L = methyl-3-hydroxy-(3-pyridyl)-2-propenedithioate L1 1, and methyl-3-hydroxy-(4-pyridyl)-2-propenedithioate L2 2, have been synthesized and characterized by elemental (C, H, and N) analysis, ESI-MS, and (IR, UV–vis, NMR) spectroscopy; the structure of 1 has been deduced by X-ray crystallography. The DNA binding and cleavage activity of the complexes have been studied. The cleavage potential of pBR322 DNA by 1 and 2 has been checked. Complex 1, which contains nitrogen of the pyridine group in the 3-position enhances DNA cleavage potential in the presence of ascorbic acid; however, the complex is protective against DNA cleavage in the presence of DMSO or H2O2. Also, 1 causes cytotoxicity against the MCF-7 breast cancer cell line. The efficient cytotoxic activity and DNA cleavage ability of 1 in the presence of ascorbic acid shows its potential anticancer properties and the need for further investigations of its potential as an anticancer drug.  相似文献   

20.
New MnII/CuII/ZnII complexes [(L1)MnCl2] (1), [(L2)CuCl2]·0.5H2O (2) and [(L2)ZnCl(H2O)][ClO4] (3), containing (2-pyridyl)alkylamine ligands, N-methyl-N,N-bis(2-pyridylmethyl)amine (L1) and methyl[2-(2-pyridyl)ethyl](2-pyridylmethyl)amine (L2), have been prepared and characterized, including X-ray crystallography. The most striking feature of the structures of these complexes is the formation of molecular ladder and lamellar topology through the crystal packing arrangement, determined by both strong O–H···Cl and weak (however, multiple) C–H···Cl hydrogen-bonding interactions, to maintain the neutral/cationic metal-ligand coordination units linked to each other. In 3, additional secondary interactions are observed involving coordinated solvent and the counter-ion. The results presented here demonstrate that (i) the choice of organic ligands to provide flexibility and inherent potential to participate in hydrogen-bonding interactions, (ii) the coordination geometry preferences of metal ions, (iii) the number of metal-bound chloride ion and (iv) the presence of solvent/counter-anion have a great influence on supramolecular network topology.  相似文献   

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