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981.
《Journal of Coordination Chemistry》2012,65(5):819-827
A series of anionic five-coordinate binary oxorhenium(V) complexes with dithiolato ligands, Bu4N[ReO(L1)2] (1a), Bu4N[ReO(L2)2] (1b), and Bu4N[ReO(L3)2] (1c), and a series of neutral octahedral ternary oxorhenium(V) complexes of mixed dithiolato and bipyridine ligands, [ReO(L1)(bpy)Cl] (2a), [ReO(L2)(bpy)Cl] (2b), and [ReO(L3)(bpy)Cl] (2c) (where L1H2 = ethane-1,2-dithiol, L2H2 = propane-1,3-dithiol, L3H2 = toluene-3,4-dithiol, and bpy = 2,2′-bipyridine), were isolated and characterized by physicochemical and spectroscopic methods. The solid state structure of 1c was established by X-ray crystallography. All the mononuclear oxorhenium(V) complexes are diamagnetic. The redox behavior of all the complexes has been studied voltammetrically. 相似文献
982.
《Journal of Coordination Chemistry》2012,65(12):1345-1353
A binuclear complex {[Mn(bpy)2(CuL)(H2O)2](ClO4)2} (2) and its CuL (1) precursor (H2L?=?2,3-dioxo-5,6?:?14,15-dichlorobenzo-7,13-diphenyl-1,4,8,12-tetraazacyclo-pentadeca-7,12-diene; bpy?=?2,2′-dipyridyl) have been synthesized and characterized structurally. Complex 1 consists of the neutral [CuL] fragments and methanol molecules. In complex 2, [Mn(bpy)2(CuL)]2+ cation, two water molecules and two perchloric anions make up of the crystal. Mn(II) is coordinated by four nitrogen atoms from two 2,2′-dipyridyl and two oxygen atoms from the Cu(II) precursor. Magnetic characterization of 2 exhibits an antiferromagnetic interaction between Cu(II) and Mn(II) ions, with J?=??74.1?cm?1. 相似文献
983.
《Journal of Coordination Chemistry》2012,65(19):3080-3091
Reaction of copper powder, manganese(II) nitrates and multidentate Schiff-base ligands in hot methanol solution led to the isolation of two new MnIII–CuII heterometallic aggregates, [Mn2 IIICu2 II(H2L)4] · (NO3)2 · 2CH3OH (1) (H4L=2-[(2-hydroxy-benzylidene)-amino]-2-hydroxymethyl-proane-1,3-diol) and [MnIIICuII 3(sae)4(MeOH)(H2O)3] · NO3 · MeOH (2) (H2sae = salicylidene-2-ethanolamine). Both compounds were characterized by elemental analysis, IR, XPS, EPR, XRPD and single crystal X-ray diffraction. Compound 1 crystallizes in the triclinic space group P 1 with a = 11.1268(4) Å, b = 11.6153(4) Å, c = 11.8129(5) Å, α = 88.435(10)°, β = 80.203(10)°, γ = 77.572(10)°, V = 1469.13(10) Å3, Z = 1, R1(wR2) =0.0300(0.0771). Compound 2 crystallizes in the monoclinic space group P21/n with a = 18.1715(7), b = 12.9931(5), c = 19.5903(8) Å, β = 97.1980(10)°, V = 4588.9(3) Å3, Z = 4, R1(wR2) = 0.0667 (0.1998). The magnetic susceptibilities of 1 and 2 display the antiferromagnetic interactions in both compounds. 相似文献
984.
《Journal of Coordination Chemistry》2012,65(19):3110-3121
Synthesis, spectral, thermal and coordination aspects of pentadentate Schiff-base complexes of the type [Mn(L)(X)] · H2O [where H2L = N,N′–diethylamine bis(1-phenyl-3-methyl-4-acetylimino-2-pyrazoline-5-ol) and X=NCS, NO3, ClO4, CN or N3] are reported. The Schiff-base ligand (H2L) and metal complexes have been characterized by elemental analysis, FT-IR, 1H-NMR, magnetic measurements, molar conductivity measurements, electronic spectra, cyclic voltammetric and thermal studies. Magnetic moment values are close to 4.9 B.M. indicating high spin complexes lacking exchange interaction. Infrared spectral data suggest coordination of the secondary amino group making the ligand pentadentate. All complexes are electrochemically inactive, indicating high stability. Thermal decomposition of the Schiff-base complexes indicates loss of water of hydration and decomposition of the ligand. Kinetic parameters such as order of reaction (n) and the energy of activation (E a) are reported using the Horowitz–Metzger method, indicating first order kinetics and giving the activation entropy (ΔS*), the activation enthalpy (ΔH*) and the free energy of activation (ΔG*). 相似文献
985.
《Journal of Coordination Chemistry》2012,65(20):3541-3550
To further explore the coordination possibilities of naphthalene-based carboxylic acids, a ZnII coordination polymer, [Zn3(L)6(bipy)2] n (1), with bulky 2-naphthol-5-carboxylate (L) and bridging 4,4′-bipyridine (bipy), was synthesized and characterized. Structural analysis reveals that 1 is a 1-D polymeric chain with trinuclear units as nodes, which are further extended via interchain secondary interactions, such as O–H ··· O hydrogen-bonding and aromatic π ··· π stacking interactions, to form an overall 3-D framework. Complex 1 exhibits strong solid-state luminescence emission at room temperature, mainly originating from intraligand π→π* transition of L. 相似文献
986.
《Journal of Coordination Chemistry》2012,65(20):3676-3687
DNA-binding properties of a number of ruthenium complexes with different polypyridine ligands are reported. The new polypyridine ligand BFIP (=2-benzo[b] furan-2-yl-1H-imidazo[4,5-f][1,10]phenanthroline) and its ruthenium complexes [Ru(bpy)2BFIP]2+ (bpy = 2,2′-bipyridine), [Ru(dmb)2BFIP]2+ (dmb = 4,4′-dimethyl-2,2′-bipyridine), and [Ru(phen)2BFIP]2+ (phen = 1,10-phenanthroline) have been synthesized and characterized by elemental analysis, mass spectra, IR, UV-Vis, 1H- and 13C-NMR, and cyclic voltammetry. The DNA binding of these complexes to calf-thymus DNA (CT-DNA) was investigated by spectrophotometric, fluorescence, and viscosity measurements. The results suggest that ruthenium(II) complexes bind to CT-DNA through intercalation. Photocleavage of pBR 322 DNA by these complexes was also studied, and [Ru(phen)2BFIP]2+ was found to be a much better photocleavage agent than the other two complexes. 相似文献
987.
《Journal of Coordination Chemistry》2012,65(22):4017-4029
Density functional theory (B3LYP/6-31G(d)) has been applied for optimization and calculation of the vibrational spectra of the compartmental hexadentate Schiff base derived from 3-formylsalicylic acid and 4,5-dichloro-1,2-phenylenediamine and 12 of its mononuclear complexes with Co(II), Ni(II), and Cu(II). Six of these complexes have the metal ion occupying the inner, N2O2, or the outer, O2O2, coordination sites in square planar geometry. The other six complexes possess octahedral geometry, occupying the inner or the outer coordination sites coordinating, additionally, to two waters. Significant changes in the ligand geometry have been observed in all complexes to permit efficient complexation with the metal. Assignments of the infrared bands are proposed based on calculations. Vibrational frequencies that are important for assignment and confirmation of the coordination sites are reported. Comparison of the total energies of the complexes reveals that inner complexes are more stable than corresponding outer complexes. Selectivity of metal ions to the coordination sites is also discussed. 相似文献
988.
《Journal of Coordination Chemistry》2012,65(1):66-76
Two copper(II) complexes, [Cu(bipy)(5-Br-2-hap)(ClO4)]2 (1) and [Cu(bipy)(2-hap)(ClO4)] (2) (where bipy?=?2,2′-bipyridine, 5-Br-2-hap?=?5-bromo-2-hydroxyacetophenone, 2-hap?=?2-hydroxyacetophenone), were synthesized and characterized. The crystal structure of 1 was determined by single crystal X-ray diffraction while 2 was reported earlier. Structural characterization reveals that the presence of bromine in 5-Br-2-hap plays a structure-determining role in dimeric 1 in comparison with the mononuclear 2 where 2-hap was used. Studies of the catalytic potential toward styrene epoxidation in homogeneous system using H2O2 as oxidant reveal that 1 is more efficient than 2 with respect to epoxide selectivity. 相似文献
989.
《Journal of Coordination Chemistry》2012,65(20):3637-3651
The potentially tridentate N,N′,O-donor N-trans-(2′-hydroxycyclohexyl)-2-aminomethylpyridine (1) forms ML2 complexes with M(II)?=?Cu, Ni, and Zn. X-ray crystal structures of the isostructural Ni(II) and Zn(II) complexes confirm bis-tridentate coordination in significantly distorted octahedral geometries as the all-cis facial isomer. Structural comparisons with the previously reported all-trans facial Cu(II) and cis,cis,trans(Npy) facial Co(III) complexes are presented. Protonation constants for 1 and stability constants with Cu(II), Ni(II), and Zn(II) are reported, with both ML and ML2 species defined. The trend for ML (log K 1 values for Cu, Ni, and Zn of 8.3, 6.9, and 5.3, respectively) is conventional. Protonation and stability constants with Cu(II) for N,N-bis(2-pyridylmethyl)amine (2) were also defined. The log K 1 value measured for 2 of 7.4 is very similar to that found for 1 of 8.3, despite the marked difference in the third donor group; it appears that the third donor of the tridentate ligand generally binds only poorly to Jahn–Teller elongated Cu(II) in solution. 相似文献
990.