Syntheses,crystal structures and characterization of divalent transition metal sulfonate complexes with O-phenanthroline

Two new complexes, [Zn(phen)₂(H₂O)₂]2L·H₂O (1) and [Cu(phen)(L)(H₂O)₂]L·3H₂O (2), where HL?= 4-aminobenzenesulfonic acid and phen = o-phenanthroline, have been synthesized and their crystal structures determined by X-ray diffraction. In the complexes the Cu(II) and Zn(II) atoms revealed two different coordination environments. Complex 1 consists of a cation [Zn(phen)₂(H₂O)₂]²⁺, in which Zn(II) is six-coordinated by four nitrogen atoms from two o-phenanthroline molecules and by two water molecules. Complex 2 has two crystallographically unique Cu(II) ions, where Cu(II) ion is five-coordinate with two nitrogen atoms of o-phenanthroline, two water molecules and one sulfonate oxygen atom. The electrochemical behavior and FT-IR of the two compounds have also been studied in detail.     

Phosphoester binding,DNA binding,DNA cleavage and in vitro cytotoxicity studies of simple heteroleptic copper(II) complexes with bidentate ligands

Abstract

Two mononuclear heteroleptic copper complexes, [Cu(±trans-dach)(bpy)](ClO₄)₂ 1a and [Cu(±trans-dach)(phen)](ClO₄)₂ 2a [dach?=?1,2-diaminocyclohexane, bpy?=?2,2′-bipyridine and phen?=?1,10-phenanthroline], were synthesized and analyzed by CHN analysis, electronic absorption, FT-IR spectroscopy, EPR, and SXRD. The molecular structures of 1a and 2a showed octahedral geometry around Cu(II). Both complexes interacted with phosphoesters and DNA. Their binding affinities with diphenylphosphate, di n-butylphosphate, trimethylphosphate, and triphenylphosphate were studied by UV–vis spectroscopy. For understanding the stereochemical role of dach ligand toward DNA interaction, enantiopure DACH complexes [Cu(R,R-trans-dach(bpy)](ClO₄)₂ 1b, [Cu(S,S-trans-dach)(bpy)](ClO₄)₂ 1c, [Cu(cis-dach)(bpy)](ClO₄)₂ 1d, [Cu(R,R-trans-dach)(phen)](ClO₄)₂ 2b, [Cu(S,S-trans-dach)(phen)](ClO₄)₂ 2c, and [Cu(cis-dach)(phen)](ClO₄)₂ 2d were synthesized and analyzed. All complexes interacted with calf thymus-DNA (CT-DNA) as studied by UV–vis spectroscopy. The nature of binding to CT-DNA was groove/electrostatic as supported by circular dichroism, cyclic voltammetry, and docking studies. Complexes were able to cleave plasmid DNA at 12.5 µM (1a–d) and 6 µM (2a–d), where 2d showed 64% Form II and 36% Form III. The in vitro cytotoxic studies of two different cancer cell lines showed inhibition with low IC₅₀ value in comparison to reference control (cisplatin). These complexes are efficient in inducing apoptosis in cancer cells, making them viable for potent anticancer activity.     

Mapping the DNA Damaging Effects of Polypyridyl Copper Complexes with DNA Electrochemical Biosensors

Several classes of copper complexes are known to induce oxidative DNA damage that mediates cell death. These compounds are potentially useful anticancer agents and detailed investigation can reveal the mode of DNA interaction, binding strength, and type of oxidative lesion formed. We recently reported the development of a DNA electrochemical biosensor employed to quantify the DNA cleavage activity of the well-studied [Cu(phen)₂]²⁺ chemical nuclease. However, to validate the broader compatibility of this sensor for use with more diverse—and biologically compatible—copper complexes, and to probe its use from a drug discovery perspective, analysis involving new compound libraries is required. Here, we report on the DNA binding and quantitative cleavage activity of the [Cu(TPMA)(N,N)]²⁺ class (where TPMA = tris-2-pyridylmethylamine) using a DNA electrochemical biosensor. TPMA is a tripodal copper caging ligand, while N,N represents a bidentate planar phenanthrene ligand capable of enhancing DNA interactions through intercalation. All complexes exhibited electroactivity and interact with DNA through partial (or semi-) intercalation but predominantly through electrostatic attraction. Although TPMA provides excellent solution stability, the bulky ligand enforces a non-planar geometry on the complex, which sterically impedes full interaction. [Cu(TPMA)(phen)]²⁺ and [Cu(TPMA)(DPQ)]²⁺ cleaved 39% and 48% of the DNA strands from the biosensor surface, respectively, while complexes [Cu(TPMA)(bipy)]²⁺ and [Cu(TPMA)(PD)]²⁺ exhibit comparatively moderate nuclease efficacy (ca. 26%). Comparing the nuclease activities of [Cu(TPMA)(phen)] ²⁺ and [Cu(phen)₂]²⁺ (ca. 23%) confirms the presence of TPMA significantly enhances chemical nuclease activity. Therefore, the use of this DNA electrochemical biosensor is compatible with copper(II) polypyridyl complexes and reveals TPMA complexes as a promising class of DNA damaging agent with tuneable activity due to coordinated ancillary phenanthrene ligands.     

A NOVEL BINUCLEAR COPPER(II) COMPLEX: BIS[1,10-PHENANTHROLINE-N,N′-MALEATO- O,O′-COPPER(II)] DIMETHANOL TETRAHYDRATE

Abstract

A novel binuclear Cu(II) complex, [Cu₂(mal)₂(phen)₂]. 4H₂O. 2MeOH (phen= 1,10-phenanthroline, mal = maleato dianion), has been synthesized and characterized by elemental analysis, IR spectroscopy, solid-state ESR analysis and X-ray single crystal study. The complex consists of [Cu(mal)(phen)] subunits with two water and one methanol solvate molecules. The subunits show a distorted planar arrangement, existing in centrosymmetrically related pairs in the crystal packing. They have a distorted four-coordinate square-planar arrangement of N and O atoms about the central Cu atom; pairs of these [Cu(mal)(phen)] subunits form dimers by interaction of the fifth position on each Cu center with an O atom of a maleato ligand of the associated subunit with a Cu-Cu distance of 3.3425(9) å. The coordination around each Cu atom is best described as distorted square-pyramidal. The lattice water and methanol molecules are also confirmed by the TG study and IR spectra. The X-band solid-state ESR spectrum at room temperature exhibits an anisotropic feature with g′ = 2.24, g′ = 2.06.     

对乙酰氨基苯甲酸和含氮配体构筑铜、锌配合物的合成、结构及性质研究

利用对乙酰氨基苯甲酸（HPABA）和邻菲咯啉（phen）、硝酸铜在DMF/CH₃OH/H₂O溶液中合成了单核铜配合物[Cu（PABA）（phen）（H₂O）₂]·（NO₃）·H₂O（1）,然后又和4,4’-联吡啶（4,4’-bpy）、硝酸锌在DMF/CH₃OH/H₂O溶液中获得配位聚合物{[Zn（PABA）₂（4,4’-bpy）]·4H₂O}_n（2）。根据X射线衍射分析结果,配合物1中每个铜离子周围有2个氮原子和3个氧原子与之配位形成畸变的四方锥配位构型,然而在配合物2中,六配位八面体构型的锌离子通过配体4,4’-联吡啶扩展为一维Zigzag型链。分别对这两个配合物的热稳定性和电化学性质进行了研究。     

Two oxovanadium complexes incorporating thiosemicarbazones: synthesis,characterization, and DNA-binding studies

An oxovanadium complex [VO(satsc)(phen)] (1) (satsc?=?salicylaldehyde thiosemicarbazone, phen?=?phenanthroline) and its derivative [VO(3,5-dibrsatsc)(phen)] (2) (3,5-dibrsatsc?=?3,5-dibromosalicylaldehyde thiosemicarbazone) have been synthesized and characterized by elemental analysis, infrared, electrospray-mass spectra, ¹H NMR, and magnetic susceptibility measurements. The DNA-binding behaviors of these complexes with calf-thymus DNA (CT-DNA) were investigated by UV-Vis absorption titration, fluorescence spectra, viscosity measurements, thermal denaturation, and circular dichroism. Both 1 and 2 bind to CT-DNA by intercalation and 1 exhibits much stronger binding affinity to CT-DNA than 2.     

DNA-interaction studies of a copper(II) complex containing ceftobiprole drug using molecular modeling and multispectroscopic methods

Abstract

The interaction of the [Cu(cef)(phen)Cl₂] complex with calf-thymus DNA (ct-DNA) at physiological pH was investigated by UV-visible spectrophotometry, fluorescence measurement, dynamic viscosity measurements, circular dichroism spectroscopy, and molecular modeling. UV-vis spectra showed 5?nm bathochromic shift of the absorption band at 270?nm along with significant hypochromicity for the absorption band of the complex. The binding constant obtained of UV-vis (1?×?10⁵ M^?1) is more in keeping with intercalators and suggests this binding mode. Moreover, thermodynamic parameters indicated that hydrogen bond and van der Waals interactions play main roles in the binding of [Cu(cef)(phen)Cl₂] to ct-DNA. In addition, [Cu(cef)(phen)Cl₂]-DNA docked model is in approximate correlation with the experimental results.     

对乙酰氨基苯甲酸和含氮配体构筑铜、锌配合物的合成、结构及性质研究(英文)

利用对乙酰氨基苯甲酸(HPABA)和邻菲咯啉(phen)、硝酸铜在DMF/CH3OH/H2O溶液中合成了单核铜配合物[Cu(PABA)(phen)(H2O)2]·(NO3)·H2O(1),然后又和4,4′-联吡啶(4,4′-bpy)、硝酸锌在DMF/CH3OH/H2O溶液中获得配位聚合物{[Zn(PABA)2(4,4′-bpy)]·4H2O}n(2)。根据X射线衍射分析结果,配合物1中每个铜离子周围有2个氮原子和3个氧原子与之配位形成畸变的四方锥配位构型,然而在配合物2中,六配位八面体构型的锌离子通过配体4,4′-联吡啶扩展为一维Zigzag型链。分别对这两个配合物的热稳定性和电化学性质进行了研究。     

Synthesis,Crystal Structure and Magnetic Properties of Diaqua(1,10-Phenanthroline-N,N')-Hydrogenmaleatocopper(Ii) Hydrogenmaleate Monohydrate

Reaction of freshly-prepared CuCO₃, phenanthroline monohydrate and maleic acid in CH₃OH/H₂O(1 : 1 v/v) at pH=2.13 yielded diaqua(1,10-phenanthroline-N,N')hydrogenmaleatocopper(II) hydrogenmaleate monohydrate, [Cu(phen)(H₂O)₂(C₄H₃O₄)](C₄H₃O₄)(H₂O), which consists of [Cu(phen)(H₂O)₂(C₄H₃O₄)]⁺ complex cations, hydrogenmaleate anions and lattice H₂O molecules. Within the complex cations, the Cu atoms are each square-pyramidally coordinated by two N atoms of one chelating phen ligand and three O atoms of two H₂O molecules and one hydrogenmaleato ligand with one H₂O molecule at the apical position (d(Cu-N) = 2.001, 2.009 Å, equatorial d(Cu-O) = 1.966 Å and axial d(Cu-O) = 2.235 Å). Through hydrogen bonding, the complex cations, hydrogenmaleate anions and lattice H₂O molecules are assembled into 1D chains, which are held together by weak Cu···O interactions (3.139 Å) to form corrugated 2D layers. Significant π-π stacking interactions between neighboring phen ligands leads to supramolecular assembly of the 2D layers. Over the temperature range 5-300 K, the complex obeys the Currie-Weiss law with an effective magnetic moment of 1.78 BM at room temperature.     

Synthesis,structure and in vitro antiproliferative activities of oxamido‐bridged dicopper(II) complexes: A comparative study of experimental evidence and molecular docking of DNA/protein binding

Two μ‐oxamido‐bridged dicopper(II) complexes, namely [Cu₂(hmpoxd)(H₂O)(phen)](ClO₄) ( 1 ) and [Cu₂(papo)(H₂O)(phen)](ClO₄)·2H₂O ( 2 ), where H₃hmpoxd and H₃papo represent N‐(2‐hydroxy‐5‐methylphenyl)‐N′‐[3‐(dimethylamino)propyl]oxamide and N‐(2‐hydroxylphenyl)‐N′‐(3‐aminopropyl)oxamide, respectively, and phen represents 1,10‐phenanthroline, were synthesized. Single‐crystal X‐ray crystallography and other methods revealed that the two copper(II) ions in complex 1 are bridged by the cis‐hmpoxd^3? with Cu···Cu separation of 5.1896(7) Å, in which the inner (Cu1) and outer (Cu2) copper(II) atoms are located in square‐planar and square‐pyramidal geometries, respectively. To evaluate the effects of bridging ligand hydrophobicity on DNA/protein binding and potential anticancer activities, comparative studies of the reactivity towards herring sperm DNA and protein bovine serum albumin (BSA) as well as cytotoxicity of complex 1 with our previously reported complex 2 were conducted theoretically and experimentally. The results indicate that the two complexes can interact interactively with DNA, and bind to BSA via the binding sites Trp213 for 1 and Trp134 for 2 . Interestingly, the in vitro anticancer activities and DNA/protein binding affinities consistently follow the order of 1 > 2 .     

Supramolecular Assemblies via Hydrogen Bonding and π-π Stacking Interactions: Crystal Structures of [Co(phen)(H2O)4]L·0.5H2O and [CO2(phen)2(H2O)2L2] with H2L = Adipic Acid

Reaction of freshly-prepared CoCO₃, phenanthroline monohydrate and adipic acid (H₂L) in CH₃OH/H₂O produced a mixture of [Co(phen)(H₂O)₄]L·0.5H₂O (1) and [CO₂(phen)₂(H₂O)₂L₂] (2). Complex 1 crystallizes in the orthorhombic space group Pbcn with cell dimensions a = 23.380(2), b = 12.347(1), c = 12.821(1) Å, and D _calc = 1.390 g/cm³ for Z = 8, and complex 2 in the triclinic space group P1; with cell dimensions a = 8.203(1), b = 9.809(1), c = 11.827(1) Å, α = 70.34(1), β = 74.81(1), γ = 71.54(1)° and D _calc = 1.592 g/cm³ for Z = 1. Complex 1 consists of [Co(phen)(H₂O)₄]²⁺ complex cations, adipate anions and crystal H₂O molecules. The Co atoms are each octahedrally coordinated by one chelating phen ligand and four water molecules with d(Co-O) = 2.041-2.097 Å and d(Co-N) = 2.144, 2.160 Å. Through hydrogen bonds, the [Co(phen)(H₂O)₄]²⁺ complex cations and adipate anions are interconnected into 2D layers, whose assembly could be ascribed to weak π-π stacking interactions between interdigitating phen ligands. Complex 2 is composed of centrosymmetric dinuclear [Co₂(phen)₂(H₂O)₂L₂) molecules, in which the Co atoms are each coordinated by two N atoms of one chelating phen ligand and four O atoms of one H₂O molecule and two adipato ligands to form distorted octahedra with d(Co-O) = 2.027-2.248 Å and d(Co-N) = 2.112, 2.162 Å. The centrosymmetric molecules are assembled via intermolecular hydrogen bonds and π-π interactions into 2D layers.     

Nuclease activity of redox/non-redox active binuclear transition metal mixed-polypyridine complexes: [M2(1,4-tpbd)(diimine)2(H2O)2]4+, M = Zn,Co, Ni,Cd, diimine = phen,bpy, dafo

Seven new transition metal complexes formulated as [M₂(1,4-tpbd)(diimine)₂(H₂O)₂]⁴⁺ [M = Zn, Co, Ni, Cd; 1,4-tpbd = N,N,N′,N′-tetrakis(2-pyridylmethyl)benzene-1,4-diamine; diimine is a N,N-donor heterocyclic base like 1,10-phenanthroline (phen), 2,2′-bipyridine (bpy), 4,5-diazafluoren-9-one (dafo)] have been synthesized and structurally characterized by X-ray crystallography: [Zn₂(1,4-tpbd)(phen)₂(H₂O)₂]⁴⁺ (1), [Zn₂(1,4-tpbd)(bpy)₂(H₂O)₂]⁴⁺ (2), [Co₂(1,4-tpbd)(phen)₂(H₂O)₂]⁴⁺ (3), [Ni₂(1,4-tpbd)(phen)₂(H₂O)₂]⁴⁺ (4), [Ni₂(1,4-tpbd)(bpy)₂(H₂O)₂]⁴⁺ (5), [Ni₂(1,4-tpbd)(dafo)₂(H₂O)₂]⁴⁺ (6) and [Cd₂(1,4-tpbd)(phen)₂(H₂O)₂]⁴⁺ (7). Single crystal diffraction reveals that the metals in the complexes are all in a distorted octahedral geometry. The interactions of the seven complexes with calf thymus DNA (CT-DNA) have been investigated by UV absorption, fluorescence, circular dichroism spectroscopy and viscosity measurements. The apparent binding constants (K_app) are calculated to be 5.2?×?10⁵ M^?1 for 1, 1.05?×?10⁵ M^?1 for 2, 5.76?×?10⁵ M^?1 for 3, 4.57?×?10⁵ M^?1 for 4, 1.29?×?10⁵ M^?1 for 5, 1.7?×?10⁵ M^?1 for 6, 2.53?×?10⁵ M^?1 for 7, the binding propensity to the calf thymus DNA in the order: 3 (Co-phen) > 1 (Zn-phen) > 4 (Ni-phen) > 7 (Cd-phen) > 6 (Ni-dafo) > 5 (Ni-bpy) > 2 (Zn-bpy). Furthermore, these complexes display efficient oxidative cleavage of supercoiled DNA; the Zn(II)/H₂O₂ and Cd(II)/H₂O₂ systems efficiently cleave DNA attributed to the peroxide ion coordinated to the Zn(II) and Cd(II), which enhanced their nucleophilicity, this is rare.     

Methyl substituent effect on one‐dimensional copper(II) coordination polymers containing biologically active ligands: Synthesis,characterization, DNA interactions and cytotoxicities

Three novel water‐soluble copper(II) complexes – {[Cu(phen)(trp)]ClO₄·3H₂O}_n ( 1 ), {[Cu(4‐mphen)(trp)]ClO₄·3H₂O}_n ( 2 ) and [[Cu(dmphen)(trp)(MeOH)][Cu(dmphen)(trp)(NO₃)]]NO₃ ( 3 ) (phen: 1,10‐phenanthroline; 4‐mphen: 4‐methyl‐1,10‐phenanthroline; dmphen: 4,7‐dimethyl‐1,10‐phenanthroline; trp: l ‐tryptophan) – have been synthesized and characterized using various techniques. Complexes 1 and 2 are isostructural, and exist as one‐dimensional coordination polymers. Complex 3 consists of two discrete copper(II) complexes containing [Cu(trp)(dmphen)(MeOH)]⁺, [Cu(trp)(dmphen)(NO₃)] and one nitrate anion. The binding interaction of the complexes with calf thymus DNA (CT‐DNA) was investigated using thermal denaturation, electronic absorption and emission spectroscopic methods, revealing that the complexes could interact with CT‐DNA via a moderate intercalation mode. The binding activity of the complexes to CT‐DNA follows the order: 3  >  2 > 1 . The pUC19 DNA cleavage activity of the complexes was investigated in the absence and presence of external agents using the agarose gel electrophoresis method. Especially, in the presence of H₂O₂ as an activator, the pUC19 DNA cleavage abilities of the complexes are clearly enhanced at low concentration. Addition of hydroxyl radical scavenger dimethylsulfoxide shows a marked inhibition of the pUC19 DNA cleavage activity of the complexes. In vitro cytotoxic effect of the complexes was examined on human tumor cell lines (Caco‐2, A549 and MCF‐7) and healthy cells (BEAS‐2B). The potent cytotoxic effect of complex 3 , with IC₅₀ values of 1.04, 1.16 and 1.72 μM, respectively, is greater relative to clinically used cisplatin (IC₅₀ = 22.70, 31.1 and 22.2 μM) against the Caco‐2, A549 and MCF‐7 cell lines.     

Synthesis,Characterization and Crystal Structure of a Ternary Cu(II) Complex with 1,10-Phenanthroline and l-Leucinate

The complex [Cu(l-Leu)(phen)(H₂O)]NO₃ has been synthesized and characterized by elemental analysis, molar conductivity, spectroscopic and X-ray diffraction methods, where phen = 1,10-phenanthroline and l-Leu = l-leucinate. The complex crystallizes in the triclinic space group Pī with two molecules in a unit cell of dimensions a = 7.288(4) Å, b = 11.588(7) Å, c = 12.349(3) Å, α = 86.388(10)^o, β = 76.175(11)°, γ = 72.132(3)°, V = 963.8(10) ų, Z = 2, D _c = 1.564 g/cm³, μ = 1.177 mm^?1, F(000) = 470, R ₁ = 0.0611, and wR ₂ = 0.0711. The copper(II) is ligated in a distorted square-pyramidal geometry by the two nitrogen atoms of phen and the amino nitrogen atom and one carboxylate oxygen atom from each independent l-Leu moiety in the basal plane, and one water oxygen at the apical position. A supramolecular configuration is formed from strong phen-phen stacking interactions between neighboring [Cu(l-leu)(phen)(H₂O)]⁺cations in the crystal.     

单核Zn(Ⅱ)/Ni(Ⅱ)含氮配体配合物的合成、晶体结构及性质

合成了2个新的配合物[Zn(BPP)2(H2O)4](2,6-NDS)·0.5H2O(1)和[Ni(phen)2(H2O)2](A-2,5-DSA)·3H2O(2)(2,6-NDS=2,6-萘二磺酸根,A-2,5-DSA=苯氨-2,5-二磺酸根,BPP=1,3-二(4-吡啶基)丙烷,phen=1,10-邻菲咯啉),用X-射线单晶衍射结构分析方法测定了配合物的晶体结构。配合物1是单核分子,Zn2+离子与2个1,3-二(4-吡啶基)丙烷的2个N原子及4个水分子配位,形成单核配位阳离子。相邻配位阳离子通过配位水分子与氮原子的氢键作用联接成一维双螺旋阳离子链。双螺旋阳离子链与未配位的2,6-萘二磺酸根阴离子通过氢键作用形成二维超分子网。配合物2是单核分子,Ni2+离子与2个1,10-邻菲咯啉分子中的4个N原子及2个水分子配位,形成单核配位阳离子。配位阳离子与游离的水分子及苯氨-2,5-二磺酸根阴离子通过氢键作用构筑成二维超分子网。     

Synthesis,X-ray crystal structure and electrochemical properties of (dithiolato)(diimine)copper(II) complexes: [Cu(mnt)(phen)] n and [Cu(dmit)(phen)] 2

Copper (II) complexes [Cu(dmit)(phen)]₂ (1) and [Cu(mnt)(phen)] _n (2) (mnt^2??=?maleonitriledithiolate, dmit^2??=?1,3-dithiole-2-thione-4,5-dithiolate, phen?=?1,10-phenanthroline) have been prepared by ligand-exchange between phen and [N(Bu)₄]₂[Cu(dmit)₂] or [N(Bu)₄]₂[Cu(mnt)₂]. Both complexes have been characterized by spectroscopic, electrochemical, and single-crystal X-ray analysis. In complex 1, dimers are extended into a two-dimensional array by weak S5–Cu contacts. In complex 2, monomers are extended into chains in a head-to-tail arrangement by weak Cu–S coordination bonds and π–π stacking interactions.     

Rhenium(II) nitrosyl complexes: synthesis,characterization, DFT calculations and DNA nuclease activity

The rhenium(II) dinitrosyl and mononitrosyl complexes, i.e. [Re(NO)₂(CN)₄]·(Phen)₂·2H₂O (1) and PhenH[Re(NO)(CN)₄(H₂O)]·(Phen)·3H₂O (2) have been isolated and characterized. The X-ray crystal structure of 2 reveals that Re(II) is octahedrally coordinated with one nitrosyl, four cyanides, and one water, with one phenanthroline protonated to compensate the charge of the Re(II) center. The crystal structure shows chemically significant non-covalent interactions like hydrogen bonding involving the uncoordinated water and π–π interactions between phenanthrolinium and phen. The structures of both complexes have been optimized by DFT. Absorption and emission spectral studies and viscosity measurements indicate that both 1 and 2 interact with calf thymus DNA through partial intercalation of DNA bases. The intrinsic-binding constants, obtained from UV–vis spectroscopic studies, are 1.2?×?10⁴ and 7.2?×?10⁴?M^?1 for 1 and 2, respectively. Both 1 and 2 are capable of inducing cleavage of plasmid DNA in the presence of H₂O₂ to form the supercoiled form to nicked circular form. The spectroscopic results of DNA binding are supported by molecular docking studies.     

对羟基苯乙酸铜(Ⅱ)、锌(Ⅱ)配位聚合物的合成、晶体结构及与DNA作用

合成了两种过渡金属配合物[M(HPAA)(phen)2]HPAA.7H2O(M=Zn,1;Cu,2;HPAA-=对羟基苯乙酸根;phen=1,10-邻菲啰啉),并通过元素分析、红外光谱、热重分析对其进行表征,用单晶X-射线衍射方法测定了配合物的晶体结构。结构分析显示,两种配合物属于异质同晶型,不对称单元都是由1个金属离子,2个对羟基苯乙酸根离子,2个邻菲啰啉分子和7个游离的水分子组成的,其中有1个对羟基苯乙酸根离子未参与配位。每个金属离子的配位数为6,处于扭曲的八面体配位环境中。另外,用荧光光谱法研究了两种配合物与DNA之间的相互作用。     

Nucleic Acid Biosensor for Detection of Human Immunodeficiency Virus Using Aquabis(1,10‐phenanthroline)copper(II) Perchlorate as Electrochemical Indicator

The electrochemical behavior of aquabis(1,10‐phenanthroline)copper(II) perchlorate [Cu(H₂O)(phen)₂]·2ClO₄, where phen=1,10‐phenanthroline, on binding to DNA at a glassy carbon electrode (GCE) and in solution, was described. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) results showed that [Cu(H₂O)(phen)₂]²⁺ had excellent electrochemical activity on the GCE with a couple of quasi‐reversible redox peaks. The interaction mode between [Cu(H₂O)(phen)₂]²⁺ and double‐strand DNA (dsDNA) was identified to be intercalative binding. An electrochemical DNA biosensor was developed with covalent immobilization of human immunodeficiency virus (HIV) probe for single‐strand DNA (ssDNA) on the modified GCE. Numerous factors affecting the probe immobilization, target hybridization, and indicator binding reactions were optimized to maximize the sensitivity and speed of the assay. With this approach, a sequence of the HIV could be quantified over the range from 7.8×10^?9 to 3.1×10^?7 mol·L^?1 with a linear correlation of γ=0.9987 and a detection limit of 1.3×10^?9 mol·L^?1.     

Synthesis, Characterization, DNA-binding Properties and DNA Cleavage of a New Ternary Copper(Ⅱ) Complex with Mixed-ligands of Tridentate Schiff Base and 1,10-Phenanthroline

A new copper(II) complex, [Cu(naph‐leu)phen]CH₃OH·0.5H₂O, in which naph‐leu is the tridentate Schiff base ligand derived from the condensation of 2‐hydroxy‐1‐naphthaldehyde and L‐leucine, phen is phenanthroline, has been synthesized and characterized by elemental analyses, IR spectra and single crystal X‐ray diffraction. The DNA‐binding properties of this complex have been investigated by absorption spectra, fluorescence spectra and circular dichroism (CD) spectra, as well as viscosity measurement. Results show that this copper(II) complex binds to calf thymus DNA (CT‐DNA) in an intercalative mode and its intrinsic binding constant K_b is 4.87×10³ L·mol^?1. Furthermore, the DNA cleavage activity of this copper(II) complex has also been investigated by submarine gel electrophoresis. Interestingly, it was found that this complex can cleave the supercoiled plasmid pBR322 DNA to both nicked and linear forms.