二(2-苯并咪唑亚甲基)胺合Zn(Ⅱ)配合物晶体和电子 结构研究及生物活性测定

合成了二(2-苯并咪唑亚甲基)胺合Zn(Ⅱ)高氯酸盐配合物[C16H15N5Zn·(ClO4)2·3H2O和C32H30N10Zn·(ClO4)2·C2H5OH,进行了元素分析、红外和紫外表征。对后者采用X射线方法测定了晶体结构,并采用G94W程序进行了量子化学计算,利用邻苯三酚自氧化法测定了所合成配合物的生物活性。     

Synthesis,crystal structure,spectroscopy, and nuclease activity of copper(II) complexes containing N,N-bis(2-pyridylmethyl)amine ligand

[Cu(bpea)Cl]ClO₄ (1) and a new copper(II) complex [Cu(bpma)(Ph-COO)(H₂O)]ClO₄ (2) [bpea?=?N,N-bis(2-pyridylmethyl)ethylamine; bpma?=?N,N-bis(2-pyridylmethyl)methylamine] have been synthesized. Complex 2 was crystallized in monoclinic space group P2₁/c with unit cell parameters a ?=?16.460(6)?Å, b ?=?11.222(4)?Å, c?=?12.522(5)?Å, and β?=?97.985(6)°. Interactions of the complexes with calf thymus DNA (CT-DNA) have been investigated by UV absorption, fluorescence, and cyclic voltammetry; thus, modes of CT-DNA binding for the complexes have been proposed. Furthermore, DNA cleavage activities by the complexes were performed in the absence of any external agents. The influence of complex concentration or reaction time on the DNA cleavage was studied.     

Amino acid and peptide bioconjugates of copper(II) and zinc(II) complexes with a modified N,N-bis(2-picolyl)amine ligand

Four chelating nitrogen ligands 2-5 derived from N,N-bis(2-picolyl)amine (bpa, 1) were synthesized, namely, (PyCH(2))(2)N-CH(2)-p-C(6)H(4)-CO(2)R (R = Me, 2, and R = H, 3) and (PyCH(2))(2)N-(CH(2))(n)-CO(2)H (n = 2, 4, and n = 5, 5). Amino acid conjugates 6 and 7 were formed by condensation of 3 with H-Phe-OMe and H-betaAla-OMe, respectively. Cu(II) and Zn(II) complexes of 1-7 were prepared and fully characterized. The X-ray structures of 1(Zn), 2(Zn), 4(Cu), and 7(Cu) were determined. The Zn complexes 1(Zn) and 2(Zn) as well as 7(Cu) show a distorted trigonal bipyramidal coordination environment in the solid state. An octahedral complex is observed for 4(Cu) which forms chains along the crystallographic b axis by intermolecular coordination of the carboxylic acid to the metal ion of a neighboring complex. Ligand 3 was used to prepare the peptide bioconjugate 8 (3-Ahx-Pro-Lys-Lys-Lys-Arg-Lys-Phe-NH(2)) with a nuclear localization signal (nls) heptapeptide by solid phase synthesis. Cu(II) and Zn(II) complexes of 8 were synthesized in situ and studied by FAB-MS, ESI-MS, UV/vis, and EPR (for 8(Cu)), and FAB-MS, ESI-MS, and NMR (for 8(Zn)). All spectroscopic results clearly support metal coordination to the bpa ligand in the bioconjugates 8(M), even in the presence of other potential ligands from amino acid side chains of the peptide. We suggest metal-peptide conjugates like 8(M) as artificial metallochaperones because they have the potential to deliver metal ions to specific compartments in the cell as determined by the peptide moieties.     

Synthesis,structure, electrochemical properties,and antioxidant activities of copper(II) and zinc(II) complexes with N,N-bis(N-ethyl-2-ylmethylbenzimidazol)allylamine ligand

N,N-bis(N-methyl-2-ylmethylbenzimidazole)aniline (EtAIDB) and its transition metal complexes, [Cu(EtAIDB)Br₂]·EtOH {dibromo[N,N-bis(N-methyl-2-ylmethylbenzimidazole)aniline] copper(II) ethanol} (1) and [Zn(EtAIDB)Br₂] {dibromo[N,N-bis(N-methyl-2-ylmethylbenzimidazole)aniline] zinc(II)} (2), have been synthesized and characterized by elemental analysis, molar conductivity, UV–visible, and IR spectroscopy. The X-ray crystallographic studies of 1 and 2 have shown two different arrangements: 1 is distorted square-based pyramidal, while 2 can be treated as distorted tetrahedral. The cyclic voltammogram of 1 represents quasi-reversible Cu²⁺/Cu⁺ pairs. In vitro antioxidant tests showed that 1 had significant antioxidant activity against superoxide and hydroxy radicals.     

Synthesis and Structure of Zinc Complex of N, N-bis ( benzimidazol-2-yl-methyl ) amine

Histidine is known to be an important biological ligand present at the active site of superoxide dismutases (SOD)1-2 and other metalloproteins. It appears to play a crucial role in the coordination chemistry of numerous metalloproteins. The ligand of di(2-benzimidazolyl-methyl)amine (L3) was chosen as the model compound of histidine. This paper reports the synthesis and crystal structure of Zn-L3 complex which is as the model compound of SOD.The complex, Zn(L3)2((ClO4)2(C2H5OH(C32H30N1…     

Synthesis,structure, and DNA-binding properties of manganese(II) and nickel(II) complexes with tris(N-ethylbenzimidazol-2-ylmethyl)amine ligand

Tris(N-ethylbenzimidazol-2-ylmethyl)amine (Etntb), [Mn(Etntb)(DMF)(H₂O)](pic)₂ (1), and [Ni(Etntb)(DMF)(H₂O)](pic)₂ (2) (pic?=?picrate) have been synthesized and characterized by elemental analyses, molar conductivities, UV–Visible spectra, and IR spectra. Single-crystal X-ray diffraction revealed that the complexes have the same arrangement with distorted octahedral coordination geometries. DNA-binding properties of the free ligand, 1, and 2 have been investigated by electronic absorption, fluorescence, and viscosity measurements. The results suggest that the ligand and its complexes bind DNA via intercalation, and their binding affinity for DNA follows the order 2?>?1?> ligand.     

Structural comparison of copper(I) and copper(II) complexes with tris(2-pyridylmethyl)amine ligand

Copper(I) complexes with the tris(2-pyridylmethyl)amine (TPMA) ligand were synthesized and characterized to examine the effect of counteranions (Br(-), ClO(4)(-), and BPh(4)(-)), as well as auxiliary ligands (CH(3)CN, 4,4'-dipyridyl, and PPh(3)) on the molecular structures in both solid state and solution. Partial dissociation of one of the pyridyl arms in TPMA was not observed when small auxiliary ligands such as CH(3)CN or Br(-) were coordinated to copper(I), but was found to occur with larger ones such as PPh(3) or 4,4'-dipyridyl. All complexes were found to adopt a distorted tetrahedral geometry, with the exception of [Cu(I)(TPMA)][BPh(4)], which was found to be trigonal pyramidal because of stabilization via a long cuprophilic interaction with a bond length of 2.8323(12) ?. Copper(II) complexes with the general formula [Cu(II)(TPMA)X][Y] (X = Cl(-), Br(-) and Y = ClO(4)(-), BPh(4)(-)) were also synthesized to examine the effect of different counterions on the geometry of [Cu(II)(TPMA)X](+) cation, and were found to be isostructural with previously reported [Cu(II)(TPMA)X][X] (X = Cl(-) or Br(-)) complexes.     

Synthesis,crystal structure and properties of a copper(II) complex with the tripod ligand tris ( N -methylbenzimidazol-2-ylmethyl)amine and 4-hydroxycinnamate

A five-coordinate copper complex with the tripod ligand tris(N-methylbenzimidazol-2-ylmethyl)amine (Mentb) and 4-hydroxycinnamate, with the composition [Cu(Mentb)(4-hydroxycinnamate)](ClO₄)?·?0.5DMF, was synthesized and characterized by means of elemental analyses, electrical conductivities, thermal analyses, IR, and UV. The crystal structure of the copper complex has been determined by single-crystal X-ray diffraction, and shows that the Cu^II atom is bonded to a tris(N-methylbenzimidazol-2-ylmethyl)amine (Mentb) ligand and a 4-hydroxycinnamate through four N atoms and one O atom, giving a distorted trigonal-bipyramidal coordination geometry (τ?=?0.78), with approximate C₃ molecular symmetry. Cyclic voltammograms of the copper complex indicate a quasireversible Cu⁺²/Cu⁺ couple. Electron spin resonance data confirm the trigonal–bipyramidal structure and indicate g _∥?<?g _⊥ with a very small value of A _∥ (57?×?10^?4?cm^?1).     

Synthesis,crystal structure and properties of a novel copper(II) complex with tripod ligand tris(1H-benzimidazol- 2-ylmethyl)amine

A five-coordinate copper complex with the tripod ligand tris(1H-benzimidazol-2-ylmethyl)amine (ntb), of composition [Cu(ntb)(H₂O)] (C1O₄)₂?·?C₅H₄N₂O₃?·?H₂O (C₅H₄N₂O₃?=?4-nitropyridine-N-oxide), was synthesized and characterized by means of elemental analyses, electrical conductivities, thermal analyses, IR, and U.V. The crystal structure of the copper complex has been determined by single-crystal X-ray diffraction, and shows that the Cu^II is bonded to a tris(1H-benzimidazol-2-ylmethyl)amine (ntb) ligand and a water molecule through four N atoms and one O atom, giving a distorted trigonal–bipyramidal coordination geometry with approximate C ₃ molecular symmetry. Cyclic voltammograms of the copper complex indicate a quasi-reversible Cu⁺²/Cu⁺ couple. Electron spin resonance data confirm a trigonal-bipyramidal structure and with g ₂?<?g _ζ and a very small value of A ₂ (20?×?10^?4?cm^?1).     

Crystal structure of copper(II) complex with N,N-bis(2-benzimidazolylmethyl)benzylamine

The copper(II) complex with N,N-bis(2-benzimidazolylmethyl)benzylamine has been synthesized and its crystal structure was determined by X-ray diffraction methods.     

A five-coordinate copper(II) perchlorate complex with tris(N-methylbenzimidazol-2-ylmethyl)amine and salicylate

A five-coordinate copper(II) complex with the tripod ligand tris(N-methylbenzimidazol-2-ylmethyl)amine (Mentb) and salicylate, with the composition [Cu(Mentb) (salicylate)](ClO₄) · 2DMF, was synthesized and characterized by elemental and thermal analyses, electrical conductivity, IR and UV-Vis spectral measurements. The crystal structure of the complex has been determined by single-crystal X-ray diffraction. The Cu(II) is five-coordinate with four N atoms from the Mentb ligand and an O atom of the monodentate salicylate ligand. The N₄O donors are in a distorted trigonal-bipyramid geometry. Cyclic voltammograms indicate a quasireversible Cu²⁺/Cu⁺ couple. The X-band EPR spectrum of the complex confirms the trigonal-bipyramidal structure with g_∥ < g _⊥ and a very small value of A_∥ (41 × 10^?4 cm^?1).     

Synthesis,characterization, and properties of copper and manganese complexes with 5-(benzimidazol-1-ylmethyl)isophthalate

Four new complexes, [Cu(L)] (1), [Cu₂(L)(dpe)_0.5]?·?2.5H₂O (2), [Mn(L)] (3), and [Mn(L)(pybim)] (4) [H₂L?=?5-(benzimidazol-1-ylmethyl)isophthalic acid, dpe?=?1,2-di(pyridin-4-yl)ethylene, pybim?=?2-(pyridin-2-yl)-1H-benzimidazole], have been synthesized under hydrothermal conditions and characterized by single-crystal and powder X-ray diffractions, FT-IR, and elemental analysis. The crystal structural analyses reveal that 1 and 4 are uninodal 3-connected 2-fold interpenetrated 2-D networks with (6³) topology, 2 shows an infinite 1-D double-stranded chain structure, and 3 exhibits a uninodal 4-connected 2-D network with (4⁴?·?6²) topology. The factors influencing the structures of the coordination polymers are discussed. In addition, the thermal stabilities of 1–4, second-order non-linear optical effect of 1, and preliminary magnetic property of 3 have also been investigated.     

Synthesis,structure and antioxidant properties of manganese(II), zinc(II) and cobalt(II) complexes with bis(benzimidazol-2-ylmethyl)allylamine

Three new metal complexes, namely: [Mn(AIDB)Cl₂]·DMF (1), [Zn(AIDB)Br₂]·CH₃OH (2) and [Co(AIDB)Cl₂]·CH₃OH (3) having a ligand bis(benzimidazol-2-ylmethyl)allylamine (AIDB), have been synthesized in high yields and characterized by elemental analyses, molar conductivities, IR, UV–Vis spectra and single-crystal X-ray diffraction. The structural analysis revealed that all the three complexes 1–3 have five-coordinated trigonal bipyramid geometry where the degree of distorting is 1>3>2. In vitro antioxidant activity assay demonstrates that the complexes 1 and 3 display high scavenging activity against hydroxyl (OH·) and superoxide (O₂^−·) radicals.

     

Dinuclear cobalt(II) and copper(II) complexes with a Py2N4S2 macrocyclic ligand

The interaction between Co(II) and Cu(II) ions with a Py(2)N(4)S(2)-coordinating octadentate macrocyclic ligand (L) to afford dinuclear compounds has been investigated. The complexes were characterized by microanalysis, conductivity measurements, IR spectroscopy and liquid secondary ion mass spectrometry. The crystal structure of the compounds [H(4)L](NO(3))(4), [Cu(2)LCl(2)](NO(3))(2) (5), [Cu(2)L(NO(3))(2)](NO(3))(2) (6), and [Cu(2)L(μ-OH)](ClO(4))(3)·H(2)O (7) was also determined by single-crystal X-ray diffraction. The [H(4)L](4+) cation crystal structure presents two different conformations, planar and step, with intermolecular face-to-face π,π-stacking interactions between the pyridinic rings. Complexes 5 and 6 show the metal ions in a slightly distorted square-pyramidal coordination geometry. In the case of complex 7, the crystal structure presents the two metal ions joined by a μ-hydroxo bridge and the Cu(II) centers in a slightly distorted square plane or a tetragonally distorted octahedral geometry, taking into account weak interactions in axial positions. Electron paramagnetic resonance spectroscopy is in accordance with the dinuclear nature of the complexes, with an octahedral environment for the cobalt(II) compounds and square-pyramidal or tetragonally elongated octahedral geometries for the copper(II) compounds. The magnetic behavior is consistent with the existence of antiferromagnetic interactions between the ions for cobalt(II) and copper(II) complexes, while for the Co(II) ones, this behavior could also be explained by spin-orbit coupling.     

Mixed ligand complexes involved in the system pyridoxamine-glycylglycine-imidazole copper(II)

Ternary as well as quaternary complexes involved in the system pyridoxamine-glycylglycine-imidazole-copper(II) have been studied by pH-metric titration at 37°C and I = 0.15 M (NaNO₃). The data were assessed by program MINIQUAD 75. The formation constants were compared with those obtained from the system of pyridoxamine-glycine-imidazole with some bivalent metal ions previously reported. They are ～ 2.5 log units less. In addition, the enhancement of quaternary complex formation has been described in terms of binary and ternary complex formation reactions. It has been also found that deprotonation of the peptidic proton of glycylglycine took place in the presence of more than one different ligand.     

N,N-二(2-苯并咪唑亚甲基)甲胺高氯酸盐的晶体和电子结构

合成了三齿配体N,N-二(2-苯并咪唑亚甲基)甲胺(MN3)的高氯酸盐.对该化合物进行了元素分析、紫外和红外表征;采用X射线衍射方法测定了该化合物的晶体结构,依据晶体结构数据使用G98程序对配体(MN3)进行了量子化学计算.     

Mixed ligand complexes of copper(II) involving amino acids and peptides

Summary The formation and stability of the mixed-ligand complexes of copper(II) with diethylenetriamine (dien) and amino acids or peptides have been investigated by potentiometric and conductometric techniques. The results indicate that the apical coordination of the ionized amide group of the peptide and the ionized alcoholatogroup of the amino acid is not possible.     

DNA binding, prominent DNA cleavage and efficient anticancer activities of tris(diimine)iron(II) complexes

The complexes rac-[Fe(diimine)(3)](ClO(4))(2)1-4, where diimine = 2,2'-bipyridine (bpy) 1, 1,10-phenanthroline (phen) 2, 5,6-dimethyl-1,10-phenanthroline (5,6-dmp) 3 and dipyrido[3,2-d:2',3'-f]quinoxaline (dpq) 4, have been isolated, characterized and their interaction with calf thymus DNA studied by using a host of physical methods. The X-ray crystal structure of rac-[Fe(5,6-dmp)(3)](ClO(4))(2)3 has been determined and the packing diagram shows the presence of two enantiomeric forms of the complex cations in the same unit cell. The structures of 1-4 in solution have also been studied using UV-Visible, Cyclic Voltammetry and ESI-MS data and all data available suggests that they retain their solid state structures even in solution. The absorption spectral titrations of the iron(ii) complexes with CT DNA reveal that the DNA binding affinities of the complexes vary in the order, 4 (K(b): 9.0 × 10(3)) > 2 (6.8 × 10(3)) > 3 (4. 8 × 10(3)) > 1 (2.9 × 10(3) M(-1)). The DNA interaction of dpq complex (4) involves partial insertion of the extended phen ring in between the DNA base pairs, which is deeper than that of phen (2). The 5,6-dmp (3) complex is involved in groove binding in the major groove of DNA. The lower DNA binding affinity of 1 is due to electrostatic interaction of the cationic complexes with exterior phosphates of DNA. The EthBr displacement assay and DNA viscosity study support these DNA binding modes and the above trend in DNA binding affinities. The complexes of 1 and 2 show induced CD (ICD) upon interaction with CT DNA while 3 and 4 bound to DNA exhibit inversion in the positive band with the helicity band showing very small changes, which implies that 3 and 4 bind enantiopreferentially to DNA. The DNA cleavage abilities of 1-4 have been observed at 10 μM concentration of complexes in the presence of 100 μM H(2)O(2) and the DNA cleavage efficiency (> 90%) follows the order 3 > 1 > 2 > 4. The anticancer activity of 1-4 against human breast cancer cell line (MCF-7) has also been studied. The IC(50) values of the complexes at different incubation time intervals of 24 and 48 h follow the order, 3 (0.8, 0.6) < 4 (20.0, 17.0) < 2 (28.0, 22.0) < 1 (32.0, 29.0 μM). Interestingly, 3 exhibits anticancer activity more potent than 1, 2 and 4 and cisplatin for both 24 and 48 h. It induces cell death both through apoptosis and necrosis mechanisms, as revealed by morphological assessment data obtained by using AO/EB and Hoechst 33258 fluorescence staining methods.     

Mixed ligand complexes of copper(II) iminodiacetate with di- and tripeptides in solution

Calorimetric, potentiometric, and spectrophotometric studies on mixed ligand complexes of copper(II) iminodiacetate and simple di- and tripeptides (GlyGly, αAlaαAla, αAlaβAla, βAlaβAla, αAlaAsn, GlyGlyGly, AlaGlyGly) have been carried out in aqueous solution at 298.15 K and ionic strength of I = 0.5 (KNO₃). The thermodynamic parameters of formation of various mixed complexes have been determined. The probable coordination modes of the complex and peptide molecules in the mixed ligand complexes are discussed.     

Mixed ligand ruthenium(II) complexes of bis(pyrid-2-yl)-/bis(benzimidazol-2-yl)-dithioether and diimines: study of non-covalent DNA binding and cytotoxicity

A series of mixed ligand ruthenium(II) complexes [Ru(pdto)(diimine)](ClO4)2/(PF6)2 1-3 and [Ru(bbdo)(diimine)](ClO4), 4-6, where pdto is 1,8-bis(pyrid-2-yl)-3,6-dithiooctane, bbdo is 1,8-bis(benzimidazol-2-yl)-3,6-dithiooctane and diimine is 1,10-phenanthroline (phen), dipyrido-[3,2-d:2',3'-f]-quinoxaline (dpq) and dipyrido[3,2-a:2',3'-c]phenazine (dppz), have been isolated and characterised by analytical and spectral methods. The complexes [Ru(pdto)(phen)](PF6)2 la, [Ru(pdto)(dpq)(Cl](PF6) 2a, [Ru(bbdo)(phen)](PF6)2 4a and [Ru(bbdo)(dpq)](ClO4)2 5 have been structurally characterized and their coordination geometries around ruthenium(II) are described as distorted octahedral. In la, 4a and 5 the two thioether sulfur and two py/bzim nitrogen atoms of the tetradentate pdto/bbdo ligand are folded around Ru(II) to give predominantly a "cis-alpha" configuration. (I)H NMR spectral data of the complexes support this configuration in solution. In [Ru(pdto)(dpq)Cl](PF6) 2a with a distorted octahedral coordination geometry, one of the two py nitrogens of pdto is not coordinated. The DNA binding constants (Kb: 2, 2.00 +/- 0.02 x 10(4) M(-1), s = 1.0; 3, 3.00 +/- 0.01 x 10(6) M(-1), s = 1.3) determined by absorption spectral titrations of the complexes with CT DNA reveal that 3 interacts with DNA more tightly than 2 through partial intercalation of the extended planar ring of coordinated dppz with the DNA base stack. The DNA binding affinities of the complexes increase with increase in the number of planar aromatic rings in the co-ligand, and on replacing both the py moieties in pdto complexes (1-3) by bzim moieties to give bbdo complexes (4-6). Upon interaction with CT DNA the complexes 1, 2, 5 and 6 show a decrease in anodic current in the cyclic voltammograms. On the other hand, interestingly, 3 and 4 show an increase in anodic current suggesting their involvement in electrocatalytic guanine oxidation. Interestingly, of all the complexes, only 6 alters the superhelicity of DNA upon binding with supercoiled pBR322 DNA. The cytotoxicities of the dppz complexes 3 and 6, which avidly bind to DNA, have been examined by screening them against cell lines of different cancer origins. It is noteworthy that 6 exhibits selectivity with higher cytotoxicity against the melanoma cancer cell line (A375) than other cell lines, potency approximately twice that of cisplatin and toxicity to normal cells 3 and 90 times less than cisplatin and adriamycin respectively.