一种含芴基的钌(II)配合物的合成及DNA键合性质

合成了一种新的钌(II)配合物[Ru(bpy)2(Hfip)](ClO4)2, 其中bpy代表2,2′-联吡啶, Hfip代表2-(9H-芴-2-基)-1H-咪唑-[4,5-f]-[1,10]-邻菲啰啉. 通过紫外可见光谱、荧光光谱、稳态荧光淬灭、与溴化乙锭的竞争实验、粘度测量和DNA热变性研究了该配合物与小牛胸腺DNA的键合性质. 结果表明, 该配合物能嵌入键合DNA, 键合常数Kb=8.6×105 L·mol-1 (50 mmol·L-1 NaCl).     

[Fe(phen)_3]·2ClO_4·2CH_2OH和[Cd(phen)_2(NO_3)_2]的合成及其晶体结构

以4-氨基苯甲酸和1,10-菲啰啉(phen)与高氯酸铁或硝酸镉反应,得到了两个邻菲啰啉的配合物:[Fe(phen)3]·2Cl O4·2CH2OH(1)和[Cd(phen)2(NO3)2](2)。并利用元素分析、红外光谱和X射线单晶衍射分析进行了表征。晶体结构分析表明,配合物(1)和(2)晶体属单斜晶系,C2/c空间群,其晶胞参数分别为:(1)a=35.708(3),b=15.903(2),c=12.204(1),β=102.504(6),V=6766(1)3,Z=8。(2)a=11.6887(6),b=15.2569(8),c=13.4630(10),β=105.9650(10),V=2310.5(2)3,Z=4。配合物(1)中phen上的氢原子与来自高氯酸根和乙二醇的氧原子形成氢键,并且相邻phen的吡啶环之间形成π~π堆积,从而使整个晶体扩展为三维网状超分子结构;配合物(2)中phen上氢原子与硝酸根的氧原子之间通过氢键使整个晶体扩展为三维网状超分子结构。     

稀土配合物Sm2(CH3COO)4(NO3)2(phen)2 的合成、 结构及非等温热分解动力学研究

在水-乙醇混合体系中, 将浓硝酸硝化的Sm2O3与1,10-邻菲啰啉反应, 用冰醋酸调节pH≈4, 形成醋酸根桥联的双核钐配合物［Sm2(CH3COO)4(NO3)2(phen)2］(phen=1,10-邻菲啰啉), 用元素分析、红外光谱和核磁共振谱等进行了表征, 并用X射线衍射测定了配合物的晶体结构, 此外, 对配合物进行了非等温热分解动力学研究. 该晶体属于三斜晶系, P1空间 群, 晶胞参数a=0.979 6(3) nm, b=0.981 3(4) nm, c=1.127 3(4) nm, α=106.666(5)°, β=113.034(5)°, γ=102.656(5)°, V=0.885 4(5) nm3, Z=1, μ=3.361 mm-1, Dc=1.915 g/cm3, F(000)=498, R1=0.059 6, wR2=0.144 8. 该配合物是双核分子, 2个Sm(Ⅲ)离子通过4个醋酸根的羧基桥联, 每个中心离子分别与周围5个来自羧基的桥氧原子、 一个硝酸根的两个氧原子和一个邻菲啰啉分子中的两个氮原子配位, 形成九配位扭曲多面体. 非等温热分解动力学研究结果表明， 配合物第一步热分解反应可能为二级反应, 其动力学方程为dα/dT=A/［βe-E/RT(1-α)2］, 分解反应的表观活化能为344.84 kJ/mol, 指前因子lnA=66.52.     

[Ru(bpy)2tpphz]2+与Zn2+形成的双核配合物的荧光性质研究

The formation of heterobimetallic ruthenium(Ⅱ) complex was investigated by absorption and emission spectra. As an intercalator of DNA， the luminescent monometallic ruthenium(Ⅱ) complex [Ru(bpy)₂tpphz]²⁺ could coor-dinate with Zn²⁺ to form the nonluminescent heterobimetallic complex [Ru(bpy)₂(tpphz)Zn]⁴⁺. The emission in-tensity of complex decreased as increasing the amounts of Zn²⁺ and the luminescence was almost lost at the ratio of [Zn]/[Ru] of 1. After binding to DNA， the peripheral coordination site on the tpphz ligand remained accessible for Zn²⁺， the coordination occurred from the oppsite side of helix with respect to intercalated [Ru(bpy)₂tpphz]²⁺ and the nonluminescent heterobimetallic complex was formed. On the other hand， the [Ru(bpy)₂(tpphz)Zn]⁴⁺ also bound to DNA by intercalation and situated the region of the intercalated [Ru(bpy)₂tpphz]²⁺ between the base pairs of DNA. The complex looked like a molecular nut (the Zn²⁺) and bolt (the [Ru(bpy)₂tpphz]²⁺).     

[Ru(bpy)2(phen)]^2+主配体上双取代效应DFT法研究

对钌联吡啶菲咯啉配合物[Ru(bpy)2(phen)]^2+及其主配体(phen)上5,6-双取代衍生物,用密度泛函(DFT)法在B3LYP/LanL2DZ水平上进行理论计算研究。探讨供电子基团(OH)和拉电子基团(F)在主配体上的取代对配合物的电子结构及相关性质,如配合物前沿分子轨道的能量、组成、光谱性质、原子的净电荷布居及配位键长键角等的影响规律。计算结果表明,取代基对该系列取代衍生物的电子结构,特别是第一激发态的电子云分布影响较大,拉电子基团(F)能活化主配体,钝化辅助配体;而代电子基团(OH)则相反。无认是供电子基团(OH),还是拉电子基团(F)都导致取代衍生物的电子基谱带红移。此外,用基于极性交替规律及极性叠加概念的多系列箭头的图示方法对主配体上的原子净电荷布居的特征作了讨论。计算结果能较好地解释有关的实验现象与规律。     

配合物Cu(phen)2 (dca)2的合成及晶体结构

合成了配合物Cu(phen)2 (dca)2(phen=C12H8N2为1,10-邻菲啰啉,dca-为二氰基氨基阴离子),用IR对其结构进行了初步表征,并测定了配合物的晶体结构.该晶体属单斜晶系,空间群为P21/c;晶胞参数a=0.8869(2)nm,b=1.4691(2)nm,c=1.9298(2)nm,β=100.90(1)°;V=2.4691(8)nm3,Z=4,F(000)=1132.00,Dc=1.496g/cm3,R=0.051,RW=0.068.中心铜(Ⅱ)离子分别与两个phen中的四个N原子和两个dca-的两个N原子配位,形成六配位的变形八面体结构.     

配合物[La(pic)3(phen)2]·CH3CN的合成及晶体结构

The Lanthanum picrate complex with 1,10-phenanthroline was synthesized, whose chemical formula can be written in [La(pic)₃(phen)₂]·CH₃CN. The crystal Xray diffraction analysis shows that crystal belongs to monoclinic with space group P2₁/a and unit cell parameters:a=17.072(4),b=16.083(4),c=17.789(4),β=106.34(2)°,V=4687(4)³, Z=4,Dc=1.735g·cm³, μ=10.106cm¹,F(000)=2448,R=0.0589,Rw=0.0589. The coordination number of La³⁺ is nine. Acetonitrile, a solvent molecule is not coordinated. Between three Pic ligands, that possesses 2 bidentate forms six member ring with La. The other is unidentate ligand. As usually, phen is bidentate ligand.     

配合物[Dy(p-MBA)3phen]2的合成，表征和非等温动力学

采用水溶液合成法,合成了新型配合物[Dy(p-MBA)3phen]2(p-MBA=对甲基苯甲酸;phen=1,10-邻菲啰啉)。 通过元素分析、红外光谱、摩尔电导和热分析(TG-DTG)等测试技术对配合物进行了表征。 研究了Dy(Ⅲ)配合物在静态空气气氛下的第一步热分解反应的非等温动力学。 通过用Popescu法和非线性等转化率积分法(NL-INT)的处理和计算,得到此步热分解反应的动力学方程为：dα/dT=(15.55×1012)/β·exp(-19825.60/T)3(1-α)2/3,平均活化能为164.83 kJ/mol,指前因子为15.55×1012 min-1。     

含二维水网的三维超分子[Ni(phen)2(H2O)2][Ni(PDC)2]•7H2O

在水溶液中合成了离子型配合物[Ni(phen)₂(H₂O)₂][Ni(PDC)₂]•7H₂O (H₂PDC＝吡啶-2,6-二甲酸, phen＝1,10-菲啰啉). 通过元素分析、红外光谱、单晶X射线衍射以及热重分析对配合物进行了表征. 晶体数据解析表明, 化合物属于三斜晶系, 空间群为P1, a＝1.0092(4) nm, b＝1.4599(6) nm, c＝1.4933(5) nm, α＝73.982(2)°, β＝78.652(2)°, γ＝75.184(3)°, V＝2.0256(13) nm³, Z＝2, F(000)＝1004, μ＝1.014 mm^－1, R₁＝0.0538, wR₂＝0.1493. 配合物中的结晶水分子形成一个(H₂O)₁₂水簇, (H₂O)₁₂水簇通过氢键连接为二维水网, 最终构成三维超分子网络.     

含二维水网的三维超分子[Ni(phen)2(H2O)2][Ni(PDC)2]•7H2O

在水溶液中合成了离子型配合物[Ni(phen)₂(H₂O)₂][Ni(PDC)₂]•7H₂O (H₂PDC＝吡啶-2,6-二甲酸, phen＝1,10-菲啰啉). 通过元素分析、红外光谱、单晶X射线衍射以及热重分析对配合物进行了表征. 晶体数据解析表明, 化合物属于三斜晶系, 空间群为P1, a＝1.0092(4) nm, b＝1.4599(6) nm, c＝1.4933(5) nm, α＝73.982(2)°, β＝78.652(2)°, γ＝75.184(3)°, V＝2.0256(13) nm³, Z＝2, F(000)＝1004, μ＝1.014 mm^－1, R₁＝0.0538, wR₂＝0.1493. 配合物中的结晶水分子形成一个(H₂O)₁₂水簇, (H₂O)₁₂水簇通过氢键连接为二维水网, 最终构成三维超分子网络.     

Enantioselective luminescence quenching of DNA light-switch [Ru(phen)2dppz]2+ by electron transfer to structural homologue [Ru(phendione)2dppz]2+

The quenching of the luminescence of [Ru(phen)(2)dppz](2+) by structural homologue [Ru(phendione)(2)dppz](2+), when both complexes are bound to DNA, has been studied for all four combinations of Delta and Lambda enantiomers. Flow linear dichroism spectroscopy (LD) indicates similar binding geometries for all the four compounds, with the dppz ligand fully intercalated between the DNA base pairs. A difference in the LD spectrum observed for the lowest-energy MLCT transition suggests that a transition, potentially related to the final localization of the excited electron to the dppz ligand in [Ru(phen)(2)dppz](2+), is overlaid by an orthogonally polarized transition in [Ru(phendione)(2)dppz](2+). This would be consistent with a low-lying LUMO of the phendione moiety of [Ru(phendione)(2)dppz](2+) that can accept the excited electron from [Ru(phen)(2)dppz](2+), thereby quenching the emission of the latter. The lifetime of excited Delta-[Ru(phen)(2)dppz](2+) is decreased moderately, from 664 to 427 ns, when bound simultaneously with the phendione complex to DNA. The 108 ns lifetime of opposite enantiomer, Lambda-[Ru(phen)(2)dppz](2+), is only shortened to 94 ns. These results are consistent with an average rate constant for electron transfer of approximately 1.10(6) s(-1) between the phenanthroline- and phendione-ruthenium complexes. At binding ratios close to saturation of DNA, the total emission of the two enantiomers is lowered equally much, but for the Lambda enantiomer, this is not paralleled by a decrease in luminescence lifetime. A binding isotherm simulation based on a generalized McGhee-von Hippel approach shows that the Delta enantiomer binds approximately 3 times stronger to DNA both for [Ru(phendione)(2)dppz](2+) and [Ru(phen)(2)dppz](2+). This explains the similar decrease in total emission, without the parallel decrease in lifetime for the Lambda enantiomer. The simulation also does not indicate any significant binding cooperativity, in contrast to the case when Delta-[Rh(phi)(2)bipy](3+) is used as quencher. The very slow electron transfer from [Ru(phen)(2)dppz](2+) to [Ru(phendione)(2)dppz](2+), compared to the case when [Rh(phi)(2)phen](3+) is the acceptor, can be explained by a much smaller driving free-energy difference.     

Effect of the ancillary ligands on the binding of ruthenium(II) complexes [Ru(dmp)2(MCMIP)]2+ and [Ru(dmb)2(MCMIP)]2+ with DNA

Two polypyridine ruthenium(II) complexes, [Ru(dmp)₂(MCMIP)]²⁺ (1) (MCMIP = 2-(6-methyl-3-chromonyl)imidazo[4,5-f][1,10]-phenanthroline, dmp = 2,9-dimethyl-1,10-phenanthroline) and [Ru(dmb)₂(MCMIP)]²⁺ (2) (dmb = 4,4′-dimethyl-2,2′-bipyridine), have been synthesized and characterized by elemental analysis, ES-MS and ¹H NMR. The DNA-binding behaviors of these complexes were investigated by electronic absorption titration, fluorescence spectroscopy, viscosity measurements and thermal denaturation. The results show that 1 and 2 effectively bind to CT-DNA; the DNA-binding affinities are closely related to the ancillary ligand.     

钌卟啉[Ru(bpy)2(MPyTPP)Cl]+与DNA作用的研究

钌卟啉(ruthenated porphyrin)是通过卟啉环上的配位基团与多吡啶钌配位而得到的一类具有丰富的光谱和化学活性的大分子配合物[1～5]. 目前, 对钌卟啉的研究大都集中在其氧化还原、电化学以及催化氧化反应活性和超分子自组装等方面, 而对钌卟啉生物功能方面的研究则鲜为报道[6].     

Synthesis,DNA‐Binding and Photocleavage Studies of the Ruthenium(II) Complexes [Ru(phen)2(ppd)]2+ and [Ru(phen)(ppd)2]2+ (ppd=Pteridino[6,7‐f] [1,10]phenanthroline‐11,13(10H,12H)‐dione,phen=1,10‐Phenanthroline)

Two new complexes, [Ru(phen)₂(ppd)]²⁺ ( 1 ) and [Ru(phen)(ppd)₂]²⁺ ( 2 ) (ppd=pteridino[6,7‐f] [1,10]phenanthroline‐11,13(10H,12H)‐dione, phen=1,10‐phenanthroline) were synthesized and characterized by ES‐MS, ¹H‐NMR spectroscopy, and elemental analysis. The intercalative DNA‐binding properties of 1 and 2 were investigated by absorption‐spectroscopy titration, luminescence‐spectroscopy studies, thermal denaturation, and viscosity measurements. The theoretical aspects were further discussed by comparative studies of 1 and 2 by means of DFT calculations and molecular‐orbital theory. Photoactivated cleavage of pBR322 DNA by the two complexes were also studied, and 2 was found to be a much better photocleavage reagent than 1 . The mechanism studies revealed that singlet oxygen and the excited‐states redox potentials of the complex may play an important role in the DNA photocleavage.     

Turning the [Ru(bpy)2dppz]2+ light-switch on and off with temperature

We report temperature-dependent excited-state lifetime measurements on [Ru(bpy)(2)dppz](2+) in both protic and aprotic solvents. These experiments yield a unifying picture of the excited-state photophysics that accounts for observations in both types of solvent. Our measurements support the notion of bpy-like and phz-like states associated with the dppz ligand and show that the ligand orbital associated with the bright state is similar in size to the corresponding orbital in the (3)MLCT state of [Ru(bpy)(3)](2+). In contrast to the current thinking, the experiments presented here indicate that the light-switch effect is not driven by a state reversal. Rather, they suggest that the dark state is always lowest in energy, even in aprotic solvents, and that the light-switch behavior is the result of a competition between energetic factors that favor the dark state and entropic factors that favor the bright (bpy) state.     

Λ-及Δ-[Ru(phen)2dppz]n+对错配DNA的识别作用的分子模拟

本文通过在ESFF(Extensible Systematic Force Field)力场下对其作用中的体系势能进行分子力学计算，分析了手性金属配合物Λ－及Δ-[Ru(phen)2dppz]^n 对错配DNA d(CCGAATGAGG)2的识别机理，并在分子水平上对其做了详细解释。     

DNA Sequence and Ancillary Ligand Modulate the Biexponential Emission Decay of Intercalated [Ru(L)2dppz]2+ Enantiomers

The bi‐exponential emission decay of [Ru(L)₂dppz]²⁺ (L=N,N′‐diimine ligand) bound to DNA has been studied as a function of polynucleotide sequence, enantiomer, and nature of L (phenanthroline vs. bipyridine). The lifetimes (τ_i) and pre‐exponential factors (α_i) depend on all three parameters. With [poly(dA‐dT)]₂, the variation of α_i with [Nu]/[Ru] has little dependence on L for Λ‐[Ru(L)₂dppz]²⁺ but a substantial dependence for Δ‐[Ru(L)₂dppz]²⁺. With [poly(dG‐dC)]₂, by contrast, the Λ‐enantiomer α_i values depend strongly on the nature of L, whereas those of the Δ‐enantiomer are relatively unaffected. DNA‐bound linked dimers show similar photophysical behaviour. The lifetimes are identified with two geometries of minor‐groove intercalated [Ru(L)₂dppz]²⁺, resulting in differential water access to the phenazine nitrogen atoms. Interplay of cooperative and anti‐cooperative binding resulting from complex–complex and complex–DNA interactions is responsible for the observed variations of α_i with binding ratio. [Ru(phen)₂dppz]²⁺ emission is quenched by guanosine in DMF, which may further rationalise the shorter lifetimes observed with guanine‐rich DNA.     

Characterization of Binding Properties of Cr(Phen)33+ and Ru(Phen)32+ Complexes with Human Lactoferrin

This work presents research about [Cr(phen)₃]³⁺ and [Ru(phen)₃]²⁺ interaction with human lactoferrin (HLf), a key carrier protein of ferric cations. The photochemical and photophysical properties of [Cr(phen)₃]³⁺ and [Ru(phen)₃]²⁺ have been widely studied in the last decades due to their potential use as photosensitizers in photodynamic therapy (PDT). The behavior between the complexes and the protein was studied employing UV–visible absorption, fluorescence emission and circular dichroism spectroscopic techniques. It was found that both complexes bind to HLf with a large binding constant (K_b): 9.46 × 10⁴ for the chromium complex and 4.16 × 10⁴ for the ruthenium one at 299 K. Thermodynamic parameters were obtained from the Van't Hoff equation. Analyses of entropy (ΔS), enthalpy (ΔH) and free energy changes (ΔG) indicate that these complexes bind to HLf because of entropy-driven processes and electrostatic interactions. According to circular dichroism experiments, no conformational changes have been observed in the secondary and tertiary structure of the protein in the presence of any of the studied complexes. These experimental results suggest that [Cr(phen)₃]³⁺ and [Ru(phen)₃]²⁺ bind to HLf, indicating that this protein could act as a carrier of these complexes in further applications.     

Caught in the Loop: Binding of the [Ru(phen)2(dppz)]2+ Light-Switch Compound to Quadruplex DNA in Solution Informed by Time-Resolved Infrared Spectroscopy

Ultrafast time-resolved infrared (TRIR) is used to report on the binding site of the [Ru(phen)₂(dppz)]²⁺ “light-switch” complex with both bimolecular (Oxytricha nova telomere) and intramolecular (human telomere) guanine-quadruplex structures in both K⁺ and Na⁺ containing solutions. TRIR permits the simultaneous monitoring both of the “dark” and “bright” states of the complex and of the quadruplex nucleobase bases, the latter via a Stark effect induced by the excited state of the complex. These data are used to establish the contribution of guanine base stacking and loop interactions to the binding site of this biologically relevant DNA structure in solution. A particularly striking observation is the strong thymine signal observed for the Na⁺ form of the human telomere sequence, which is expected to be in the anti-parallel conformation.