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1.
The reaction between 1,3,5-tris(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene (titmb) and [Ag(NH3)2][Hsal] (H2sal=salicylic acid) produces novel complex [Ag2(titmb)2][Hsal]2 · 3H2O (1). There are two unique silver centers in complex 1 with one serving as a trigonal node and the other one as a linear node. Interestingly, there are two sorts of titmb ligands in complex 1, one acting as a three-connecting ligand and the other one as a two-connecting (bridging) ligand. The silver centers are linked by titmb ligand to form 2D puckered layers containing M5(titmb)5 macrocyclic motifs, which is large enough to allow the bridging titmb ligands from the neighboring layers to be completely enclosed in. Namely, two neighboring independent layers interpenetrated each other in a parallel fashion without the occurrence of catenation to give a 3D structure.  相似文献   

2.
Three new supramolecular complexes based on a 2-(pyrazin-2-yl)-1H-benzimidazole (Hpbi) and a series of Cd(II) salts have been solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction analysis. Reaction of CdCl2·2.5H2O with Hpbi afforded a one-dimensional chain [Cd(Hpbi)Cl2] (1), which exhibits a three-dimensional (3-D) supramolecular architecture through intermolecular X-H···Cl (X = N and C) hydrogen bonds and π-π stacking interactions. When using CdBr2·4H2O instead of CdCl2·2.5H2O under similar reaction conditions, a bisnuclear complex [Cd(Hpbi)2Br2] (2) is obtained, which obviously exhibits intermolecular X-H···Br (X = N and C) hydrogen bonds and π-π stacking interactions. When CdI2 take place of CdCl2·2.5H2O, a mononuclear complex, [Cd(Hpbi)2I2] (3), is isolated, which shows a 3D supramolecule framework formed by intermolecule hydrogen bonds and π-π packing interactions. Interestingly, the Hpbi ligand exhibits the same coordination modes in complexes 1-3. It is noteworthy that the radius of anions plays an important role in affecting the structures and luminescent intensity of the final products. The TGA for 1-3 have been investigated and discussed in detail.  相似文献   

3.
The potentially tritopic bridging ligand 4-(pyrid-4-yl)-1,2,4-triazole (pytz) reacts with cadmium(II) nitrate tetrahydrate, Cd(NO3)2·4H2O and sodium dicyanamide (Na-dca) to form the molecular complex [Cd(dca)2Npy-pytz)2(H2O)2] (1). The cadmium atom lies on a center of inversion and is coordinated in a slightly distorted octahedral geometry by the trans-oriented pytz ligands, dicyanamide anions and aqua ligands. The pytz ligand coordinates through the Npyridin atom to the metal atom. The molecular complexes are connected to a 3D supramolecular network by O-H···Ndca and O-H···Ntriazole hydrogen bonds. From zinc(II) bromide and pytz the compound 1D-[ZnBr2(μ-κNpy,Ntz-pytz)] (2) is obtained where the pytz-ligand bridges between the tetracoordinated zinc(II) atoms through coordination of its Npyridine- and Ntriazole-atoms. Adjacent chains are connected through C-H···Br and C-H···N hydrogen bonds to form a 3D supramolecular structure. Single crystals of 2 crystallize homochiral in the non-centrosymmetric space group P212121. The origin of the homochirality is the formation of hydrogen-bonded helices around the 21 screw axes with the same sense of rotation (left-handed or M in the investigated crystal). Cd(NO3)2·4H2O, pytz and sodium thiocyanate (NaSCN) give the framework 3D-[Cd(μ-SCN)2(μ-κNpy,Ntz-pytz)] (3). Parallel layers of 2D-{Cd(μ-SCN)2}-nets with distorted (6,3)-net topology are assembled by the bridging pytz-ligands into a 3D-structure. The pytz-ligand bridges between two cadmium atoms by Npyridine- and Ntriazole-coordination.  相似文献   

4.
Single-crystal X-ray structures and high-resolution solution NMR studies of Λ-β1-[Co(R,R-picchxn)(R-phe)](ClO4)2 · H2O and Λ-β1-[Co(R,R-picchxn)(R-tyr)](ClO4)2 · 2H2O (pheH=phenylalanine, tyrH=tyrosine) are reported. In the former, the aromatic side group of the phenylalanine ligand is extended, as is found in related halide salts. In the tyrosine analogue, the aromatic ring adopts a conformation such that a weak intramolecular NH-π interaction with a NH group of the tetradentate ligand is stabilized. The interaction is rather weak and is not particularly favoured in solution, as revealed by 1H NMR. The β1 complex of phenylalanine is not the thermodynamically stable diastereoisomer. Equilibration experiments give a mixture of Λ-β1, Λ-β2 and Δ-α diastereoisomers in D2O solution, the α diastereoisomer being more stable than either of the β complexes by about 1 kJ mol−1 at 298.2 K. Intramolecular π-π and NH-π interactions are responsible for the stabilization of the α complex, demonstrating the significance of the cooperative effects of such interactions. The ternary cobalt complexes described in this study could act as simple model systems for investigating the discriminatory effects of analogous weak interactions that occur in a complex biological setting.  相似文献   

5.
The reaction of the new bidirectional ligand 3-phenyl-5-(2-pyridyl)-4-(4-pyridyl)-4H-1,2,4-triazole (pyppt) with Cu(ClO4)2 · 6H2O in a 2:1 molar ratio in EtOH affords the complex [CuII(pyppt)2(ClO4)2] · H2O (1) as a microcrystalline turquoise solid. Recrystallisation of complex 1 from MeCN by vapour diffusion of Et2O gives blue crystals of the monomeric octahedral complex [CuII(pyppt)2(ClO4)2] · MeCN (2). In contrast, addition of EtOH to a solution of complex 1 in MeCN followed by slow evaporation yields blue crystals of the five-coordinate polymeric complex {[CuII(pyppt)2](ClO4)2 · EtOH} (3). The structures of both complexes have been determined by single crystal X-ray diffraction.  相似文献   

6.
The preparation and characterization of manganese(III) complexes containing the quadridenate ligand, N,N′-bis(aminobenzylidene)-1,2-ethanediamine (H2amben), and its previously unreported analogue, N,N′-bis(2-amino-5-nitro-benzylidene)-1,2-ethanediamine (H2nitroamben), are described. The new manganese(III) halide/pseudohalide complexes, Mn(amben)X · nH2O and Mn(nitroamben)X · nH2O (X = Cl, Br, I, NCS; n =  0.5 or 1), were isolated as red-brown, microcrystalline solids, which were characterized fully.  相似文献   

7.
Two new manganese(II) complexes, [Mn(L1)(L1H)(ClO4)(H2O)][ClO4]2·0.5CH3CN·H2O (1) [L1 = trans-(±)2-(2,5-di(pyridin-2-yl)-4,5-dihydro-1H-imidazol-4-yl)pyridine)] and [Mn2(μ-L2)2(H2O)3(CH3CN)3][ClO4]4·2CH3CN (2) [L2 = cis-(±)2-(2,5-di(pyridin-2-yl)-4,5-dihydro-1H-imidazol-4-yl)pyridine)], have been prepared and examined by single-crystal X-ray diffraction analysis, showing that complex 1 is a mononuclear compound, whereas complex 2 is a dinuclear species. The cis/trans isomers L1 and L2 have similar coordination properties, but behave as bidentate and tridentate chelating ligands, respectively, giving distorted octahedral metal coordination geometries. X-ray diffraction studies revealed that the molecular and crystal structures are stabilized by a series of intra- and intermolecular interactions. In both cases extended supramolecular networks are generated, in compound 1 through O-H···O, O-H···N, N-H···O, N-H···N, C-H···O, C-H···N, C-H···π and π···π interactions, and in compound 2 through O-H···O, O-H···N, C-H···O and π···π interactions. The observed structural differences between the two metal complexes might be a consequence of these stabilizing effects.  相似文献   

8.
Two 1D organic-inorganic coordination polymers, [Cd(3-pmpmd)(CH3CN)2(H2O)2]n · 2n(ClO4)2 (1) and [Zn(3-pmpmd)1.5(H2O)2]n · 2n(ClO4)2 · nCH3CN (2), were obtained from M(ClO4)2 (M = Cd, Zn) and the semi-flexible 3,3′-N-donor bis-pyridyl ligand 3-pmpmd: 1 has an 1D zigzag framework with 3-pmpmd in the ZT-mode (anti, trans-) conformation, while 2 has an 1D rod and loop network with 3-pmpmd in both ZT- and ZC-mode (anti, cis-) conformations. Results showed that the metal ions could influence the coordination mode of a semi-flexible bis-pyridyl ligand.  相似文献   

9.
Using bis(3,5-dimethylpyrazol-1-yl)methane as an N-N donor ligand, a trans-[RuIII(N-N)2Cl2]+ core has been isolated from the direct reaction of the ligand with RuCl3 · xH2O and characterized structurally for the first time. The core displays a rhombic EPR spectrum and a quasireversible Ru(II/III) couple with an E1/2 of −0.34 V versus NHE.  相似文献   

10.
When the complexes [Cu(L1)(H2O)](ClO4)21, where L1 = 4-methyl-1-(pyrid-2-ylmethyl)-1,4-diazacycloheptane, and [Cu(L2)Cl2] 2, where L2 = 4-methyl-1-(quinol-2-ylmethyl)-1,4-diazacycloheptane are interacted with one/two equivalents of bis(p-nitrophenylphosphate, (p-NO2Ph)2PO2, BNP), no hydrolysis of BNP is observed. From the solution the adducts of copper(II) complexes [Cu2(L1)2((p-NO2Ph)2PO2)2]-(ClO4)23 and [Cu(L2)((p-NO2Ph)2PO2)2]·H2O 4 have been isolated and structurally characterised. The X-ray crystal structure of 3 contains two Cu(L1) units bridged by two BNP molecules. The Cu···Cu distance (5.1 Å) reveals no Cu-Cu interaction. On the other hand, the complex 4 is mononuclear with Cu(II) coordinated to the 3N ligand as well as BNP molecules through phosphate oxygen. The trigonality index (τ, 0.37) observed for 4 is high suggesting the presence of significant trigonal distortion in the coordination geometry around copper(II). The complexes are further characterized by spectral and electrochemical studies.  相似文献   

11.
The reactions of methyl 2-pyridyl ketone oxime, (py)C(Me)NOH, with MSO4 · xH2O (M = Zn, x = 7; M = Cd, x = 8/3), in the absence of an external base, have been investigated. The synthetic study has led to the two new complexes [Zn(SO4){(py)C(Me)NOH}(H2O)3] · H2O (1 · H2O) and [Zn2(SO4)2{(py)C(Me)NOH}4] · (py)C(Me)NOH [2 · (py)C(Me)NOH], and the coordination polymer [Cd(SO4){(py)C(Me)NOH}(H2O)]n · [Cd(SO4){(py)C(Me)NOH}(H2O)2]n (3). In the three complexes the organic ligand chelates through its nitrogen atoms. The sulfate anion in 1 · H2O is monodentate; the complex molecule is the mer isomer considering the positions of the aqua ligands. The ZnII centers in 2 · (py)C(Me)NOH are bridged by two syn, anti η112 ligands; each metal ion has the cis-cis-trans disposition of the coordinated sulfate oxygen, pyridyl nitrogen and oxime nitrogens, respectively. The molecular structure of 3 is unique consisting of two different linear and ladder - type chains. π-π stacking interactions and/or hydrogen bonds lead to the formation of interesting supramolecular architectures in the three complexes. The thermal decomposition of complex 3 has been studied. Characteristic vibrational (IR, Raman) bands are discussed in terms of the nature of bonding and the structures of the three complexes.  相似文献   

12.
New ternary transition metal complexes of formulations [Ni(bpa)(p-AB)Cl]n · 3nH2O (bpa = 2,2′-bipyridylamine, p-AB = aminobenzenecarboxylic acid) (1), [Cu(bpa)(p-AB)Cl] · H2O (2), [Zn(bpa)(p-AB)2] · H2O (3) are prepared, their structural features are characterized by crystal structural studies, and their DNA binding propensity has been evaluated by fluorescence and viscosity method. In complex 2 and 3, both bpa and p-AB act as the bidentate N and O-donor ligand, respectively. While in complex 1, p-AB acts as a rare tridentate ligand. In the packing pattern of each complex, π-π interaction in their solid state is also described. The complexes show the competitive inhibition of ethidium binding to DNA, and the DNA binding propensity can be reflected as the relative order: 1 > 2 > 3.  相似文献   

13.
The protonation constants of 1,3,5-trideoxy-1,3,5-tris(2-hydroxyl-benzyl)amino-cis-inositol (thci) in I = 1 M (NaClO4) were determined to be: pKa1 5.96 ± 0.03, pKa2 7.21 ± 0.01, pKa3 8.32 ± 0.07, pKa4 8.95 ± 0.06. The solvent extraction studies were consistent with the formation of the Ln(thci)3+ and complexes. The log of the stability constants (log β1 and log β2) at 25 °C in 1 M (NaClO4) at pH 4 for formation of these complexes are reported. Laser luminescence measurements of the 7F0-5D0 transition of Eu(III) complexed by thci indicated two species. The shifts in the peaks relative to that of Eu(aq)3+ were comparable to the values reported for other complexes of Eu(III) with organic ligands, but the intensities were greater. Luminescence lifetime measurements of the fluorescence spectra indicated that the complex has 5 inner sphere water molecules bound to the Eu(III) cation at pH 6.71-8.52. This was consistent with bidentate chelation of Eu(III) with each thci molecule. gaussian view energy calculations indicated bonding for M(III) to the amino and hydroxyl groups of the cyclohexanetriol and (2-hydroxybenzyl)amino moieties in the Ln(thci)3+ complex.  相似文献   

14.
Knoevenagel condensation of 4-(dimethylamino)benzaldehyde with 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) gives the donor-acceptor ligand 2-(4-dimethylaminobenzylidene)-4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (dbpcd). The reaction of dbpcd with PtCl2(cod) affords the platinum(II) complex PtCl2(dbpcd) in high yield. The free dbpcd ligand and PtCl2(dbpcd) have been isolated and fully characterized in solution by IR and NMR spectroscopies, and the solid-state structure of PtCl2(dbpcd) determined by X-ray diffraction analysis. PtCl2(dbpcd), as the 1.5CH2Cl2 solvate, crystallizes in the triclinic space group , a = 11.7412(7) Å, b = 12.0486(7) Å, c = 14.4781(9) Å, α = 82.866(1), β = 75.049(1), γ = 83.905(1), V = 1957.6(2) Å3, Z = 2, and Dcalc = 1.678 mg/m3, R = 0.0291 and wR2 = 0.0723 for 8315 reflections with I > 2σ(I). The molecular structure of PtCl2(dbpcd)·1.5CH2Cl2 consists of a square-planar platinum architecture containing two chlorines and the ancillary dbpcd diphosphine ligand. The redox properties of the dbpcd ligand and PtCl2(dbpcd) have been explored by cyclic voltammetry, and these data are discussed with respect to extended Hückel MO calculations.  相似文献   

15.
The synthesis and X-ray crystal structure of the complex {[CuII(Ph2PBPT)(bpy)](ClO4)2 · 2DMF} where Ph2PBPT=4,4-(1,4-phenylene)bis[3-phenyl-5-(2-pyridyl)-4H-1,2,4-triazole], bpy=2,2-bipyridine and DMF=N,N-dimethylformamide are reported. In this one-dimensional coordination polymer the Cu2+ ions are in a distorted octahedral N6 coordination environment made up of two Ph2PBPT molecules, each chelating via one pyridine and one triazole nitrogen, and one bpy co-ligand. Within the zig-zag chain thus formed the shortest distance between two metal centres across the Ph2PBPT ligand is 13.305(3) Å while it is 10.009(3) Å between two chains. This complex represents the first structurally characterised example of a coordination compound incorporating a chelating 4,4-bis(4H-1,2,4-triazole) as a ligand.  相似文献   

16.
Two ruthenium nitrosyl bis-pyridyl/biscarboxamido compounds, [Ru(NO)(bpp)Cl · 2H2O] [bpp = N,N′-bis(2-pyridinecarboxamide)-1,3-propane dianion] and [Ru(NO)(bpe)Cl · 2H2O] [bpe = N,N′-(bis-2-pyridinecarboxamide)-1,2-ethane dianion] have been characterized by 1H NMR, 13C{1H} NMR, and IR spectroscopies, electrospray ionizaton mass spectrometry, and X-ray crystallography.  相似文献   

17.
Seven new organic-inorganic hybrid compounds containing inorganic polyoxometalates and trigonal organic ligand 2,4,6-tris-(3/4-pyridyl)-1,3,5-triazine (3/4-tpt), namely [Mo8O26M(Htpt)2(H2O)2]n (M = Zn (1), Co (2), Ni (3)), [Mo8O26Cu(Htpt)2(H2O)2]n·2nH2O (4), [Mo8O26(H2tpt)2]·6H2O (5), [Mn(Mo4O13)(4-tpt)2]n (6) and [Fe3(Mo4O15)(3-tpt)]n·nH2O (7), were synthesized hydrothermally and characterized by EA, IR, TG, and PXRD techniques. Single crystal X-ray structural analysis revealed that compounds 1-4 are 1-D coordination polymers constructed from [Mo8O26]4− cluster and [M(Htpt)2(H2O)2]4+ fragments. Compound 5 is an isolated cluster composed of [Mo8O26]4− anion and monodentate H2tpt2+ cation. 3-Tpt ligands in 1-5 are partially protonated and act as monodentate ligands. Octamolybdates adopt β- and γ-[Mo8O26]4− structural mode in compounds 1-4 and 5, respectively. In compound 6, each [Mo4O13]2− tetramer links four Mn(II) ions to form a 2-D wave-like polymeric layer. The 2-D [MnMo4O13] bimetallic layers are pillared by neutral 4-tpt bidentately to generate a 3-D metal-organic framework. Compound 7 is a 3-D coordination polymer constructed from 2-D [Fe3(Mo4O15)] bimetallic polymeric layer and pillared by neutral tridentate 3-tpt. These compounds are thermal stable under 250 °C. The compounds 1 and 5 display luminescence with emission maximum at 481 and 442 nm, respectively.  相似文献   

18.
Reaction of NH4VO3 with 2,6-pyridinedimethanol in water at 85 °C followed by the room temperature addition of HCl (aq) yields [HVO2(pydim)]x (pydim = 2,6-pyridinedimethanolato dianion), as a sparingly soluble off-white solid. This acid may be deprotonated by titration with NaOH (aq), yielding Na[VO2(pydim)] · 4H2O, which has been structurally characterized by single-crystal X-ray diffraction. Treating Na[VO2(pydim)] · 4H2O with HCl (aq) regenerates [HVO2(pydim)]x, but reaction with additional NaOH (aq) displaces the pyridinedimethanolato ligand from the vanadium center. Similarly, treating [HVO2(pydim)]x with excess HCl (aq) strips the pyridinedimethanolato ligand from the vanadium center and yields the adduct [H3(pydim)]+Cl as one component in a mixture of products. This adduct has been structurally characterized by single-crystal X-ray diffraction. The optimum pH range for stable dioxovanadium(V) complexes stabilized by the 2,6-pyridinedimethanolato ligand is at least 1.5-9.4.  相似文献   

19.
Three new complexes [Cu2(mip)2(bbi)]n (1), {[Cu2(tbip)2(bbi)2(H2O)]·2H2O}n (2) and {[Co2(tbip)2(bbi)2]·2H2O}n (3), were prepared through hydrothermal reactions of Cu(II) and Co(II) acetate with H2mip or H2tbip (H2mip = 5-methyl isophthalic acid and H2tbip = 5-tert-butyl isophthalic acid) and the flexible ligand bbi (bbi = 1,1′-(1,4-butanediyl)bis(imidazole)). All these complexes were structurally characterized by elemental analysis, IR spectroscopy and X-ray single-crystal diffraction. Complex 1 exhibits a 3D network, which are constructed from 2D carboxylate layer and bbi pillar. Complex 2 possesses a 2D layer structure, and exists extensive hydrogen-bonding interactions, while complex 3 is constructed from 2D layers which consists of alternating left- and right-handed helical chains, and further assembled to form a 3D framework by hydrogen-bonding interactions. The thermal stabilities of the corresponding complexes have been briefly investigated. In addition, dominant antiferromagnetic coupling was observed in complex 1.  相似文献   

20.
A new distorted square planar (two CuN2 planes making an angle of ∼43°) copper(II) complex [Cu(L4)] · 0.5EtOH · 0.5MeOH (1) of a deprotonated tetradentate pyridine amide ligand [H2L4 = N,N′-bis(2-pyridinecarboxamide)-2,2′-biphenyl] has been synthesized and structurally characterized. Absorption and EPR spectroscopic properties have also been studied. The E1/2 values (CuII/CuI redox process) of the title complex along with a selected group of structurally characterized CuN4 pyridine amide complexes with systematically varied structural, electronic/steric, and chelate-ring size effects, imposed by the coordinating ligands, have been determined and the observed trend has been rationalized.  相似文献   

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