三菲咯啉合铁手性配合物键合DNA的立体选择性

应用光谱法研究了手性金属配合物［Ｆｅ（ｐｈｅｎ）３］＾２＋与小牛胸腺ＤＮＡ的作用，确定了△型异构体对Ｂ型右手螺旋ＤＮＡ有优先键合的立体选择性。     

钌多吡啶配合物的合成及结合DNA的研究

合成了咪唑并［ｆ］邻菲咯啉（ＩＰ）和２－苯基咪唑并［ｆ］邻菲咯啉（ＰＩＰ）两种新的配体及［Ｒｕ·（ｂｐ）２（ＩＰ）］￣（２＋）（简称ｂ２ＩＰ）、［Ｒｕ（ｂｐｙ）２（ＰＩＰ）］￣（２＋）（简称ｂ２ＰＩＰ）、［Ｒｕ（ｐｈｅｎ）２（ＩＰ）］￣（２＋）（简称ｐ２ＩＰ）和［Ｒｕ（ｐｈｅｎ）２（ＰＩＰ）］￣（２＋）（简称ｐ２ＰＩＰ）４种新混配物。用电子吸收、稳态发光、圆二色谱研究了配合物与小牛胸腺ＤＮＡ的结合情况。总的结合强度顺序为：ｂ２ＩＰ＜ｂ２ＰＩＰ≤ｐ２ＩＰ＜ｐ２ＰＩＰ，这与配体的平面大小、π电子扩展程度和疏水性顺序（ｂｐｙ＜＜ｐｈｅｎ＜ＩＰ＜ＰＩＰ）是一致的。证明了配合物与ＤＮＡ存在插入结合。ＣＤ谱表明这种结合有对映体选择性．     

过渡元素Dawson结构的钨钒磷四元杂多配合物的合成与表征

制备了两个系列１２种尚未见文献报道的过渡金属Ｄａｗｓｏｎ结构的钨钒磷四元杂多配合物。经元素分析和热重分析确定配合物通式为Ｋ９，１０［Ｐ２Ｍ（Ｈ２Ｏ）Ｗ１５Ｖ２Ｏ６１］．ｘＨ２Ｏ和Ｋ１０，，１１［Ｐ２Ｍ（Ｈ２Ｏ）Ｗ１４Ｖ３Ｏ６１］．ｘＨ２Ｏ）（Ｍ＝Ｆｅ＾３＾＋，Ｃｏ＾３＾＋，Ｎｉ＾２＾＋，Ｍｎ＾２＾＋，Ｃｕ＾２＾＋，Ｚｎ＾２＾＋＿），采用ＩＲ，ＵＶ，ＮＭＲ，ＥＳＲ和ＸＲＤ等方法进行了结构表征。     

硝酸镧与N,N—双（苯并三唑甲）—[2,2]及N—三唑甲基—[2,2]配合物…

合成了Ｌａ（ＮＯ３）３与Ｎ，Ｎ－双（苯半三唑甲基）－［２，］［Ｌ（Ｉ）］及Ｎ－三唑甲基－［２，２］（Ｌ（Ⅲ）的配合物单晶，测定了结构，并进行了元素分析，红外光谱及热分析表征。Ｌａ＾３＋离子均与［２，２］环中六个杂原子及三个ＮＯ＾３－离子配位，稍偏离环平面，三个ＮＯ＾３－离子分别位于环平面的两侧，初步讨论了［２，２］环所连接支链对配合的结构及其稳定性的影响。     

分光光度法测定［Fe（phen）_3］~（2＋）在酸性介质中离解反应的动力学参

分光光度法测定［Ｆｅ（ｐｈｅｎ）＿３］￣（２＋）在酸性介质中离解反应的动力学参数李金良，卢祥生，王超，梁燕波（徐州师范学院化学系，江苏２２１００９）分光光度法测定过渡金属配合物离解反应的动力学参数，常被选作高等学校物理化学实验内容￣［１，２］。反应体...     

μ—4,4‘—联吡啶桥联三核Cu（Ⅱ）配合物的合成和磁性

合成了３种以４，４’－联吡啶为配体的三核环状Ｃｕ（Ⅱ）配合物［Ｃｕ３（４，４＇－ｂｐｙ）３．（ｐｈｅｎ）３］（ＣｌＯ４）６．２Ｈ２Ｏ（１），［Ｃｕ３（４，４＇－ｂｐｙ），（ｂｐｙ）３］（ＣｌＯ４）６．Ｈ２Ｏ（２）和［Ｃｕ３９４，４＇－ｂｐｙ）３．（ＮＯ２－ｐｈｅｎ）３］（ＣｌＯ４）６．６Ｈ２Ｏ（３）。经元素分析，电导，ＩＲ，电子光谱，ＥＳＲ，磁化率等方法进行了表征，推定该配合物具有以４，４’－联吡     

咪唑并邻菲咯啉类配体的钌配合物的光谱研究

多吡啶钌配合物在光物理、光化学和核酸结构探测等方面都扮演着重要的角色。该文对钌（Ⅱ）与配体（Ｌ）咪唑并［４,５－ｆ］邻菲咯啉,２－（４－取代基）苯基咪唑并［４,５－ｆ］邻菲咯啉形成的同配配合物ＲｕＬ３２＋和混配配合物Ｒｕ（ｂｐｙ）２Ｌ２＋、Ｒｕ（ｐｈｅｎ）２Ｌ２＋（ｂｐｙ和ｐｈｅｎ分别为２,２′－联吡啶和邻菲咯啉）的电子吸收光谱,发光光谱,红外光谱进行了综合研究,测定了发光配合物的发光寿命。     

钪—铬天青S—镍—邻菲罗啉混合多核配合物显色反应的研究

在弱酸介质中，钪与铬天青Ｓ形成的阴离子配合物，可以和镍－邻菲啉配阳离子通过静电引力成缔合型混合多核配合物。本文详细地研究了钪一铬天青Ｓ－镍－邻菲罗啉配合物的形成条件及反应过程。配合物的最大吸收峰位于６３０ｎｍ处，摩尔吸光系数ε５３０＝３．３１×１０＾４Ｌ．ｍｏｌ＾－＾１．ｃｍ＾－＾１，各组分的摩尔比；Ｓｃ＋ＣＡＳ＋Ｎｉ＋Ｐｈｅｎ＝２＋６＋３＋３，相应的分子式为［Ｓｃ（ＣＡＳ）３］２［ＮｉＰｈｅｎ     

［Ln（HCOO）_3·phen·C_2H_5OH］［Ln＝Pr、Gd］的电子

［Ｌｎ（ＨＣＯＯ）＿３·ｐｈｅｎ·Ｃ＿２Ｈ＿５ＯＨ］［Ｌｎ＝Ｐｒ、Ｇｄ］的电子结构和化学键董南，朱龙观，蔡国强，吴念慈（杭州大学化学系杭州３１００２８）关键词：化学键，电子结构，ＩＮＤＯ，配合物［Ｌｎ（ＣＣｌ＿３ＣＯＯ）＿３·ｐｈｅｎ·Ｃ＿２Ｈ＿５Ｏ...     

Cu（phen）^2＋3和Cu（bpy）^2＋3与6—巯基嘌呤,腺嘌呤相互作 …

在ｐＨ为７．０的磷酸盐缓冲溶液中，用荧光光谱，紫外光谱，电化学及紫外光谱电化学等方法研究了铜配合物与６－巯基嘌呤，腺嘌呤的相互作用，结果表明，Ｃｕ（ｐｈｅｎ）＾２＋２和Ｃｕ（ｂｐｙ）＾２＋３与６－巯基嘌呤，腺嘌呤发生了相互作用，但作用程度不同，根据荧光光谱实验数据计算出Ｃｕ（ｐｈｅｎ）２＋３和Ｃｕ（ｂｐｙ）＾２＋３与６－巯基嘌呤，腺嘌呤的配位比均为１：１，它们与６－巯基嘌呤作用的配位常数分别为２．     

新型双核配合物的形成、与DNA的作用机制及荧光性质研究

利用紫外、荧光和粘度等方法研究了含不同配体的钌(II)配合物[Ru(phen)₂CImP]^2＋(CImP＝3,4-二羟基-咪唑并[4,5-i][1,10]邻菲咯啉)和[Ru(phen)₂TPPZ]^2＋(TPPZ＝四吡啶[3,2-a:2',3'-c:3',2'-h:2'',3''-j]吩嗪)与DNA的作用机制, 并研究了配合物与Zn^2＋配合后荧光性质变化. 结果表明[Ru(phen)₂TPPZ]^2＋与DNA以插入模式作用, 而[Ru(phen)₂CImP]^2＋与DNA则以沟面结合模式作用. 向配合物溶液中滴加Zn^2＋后, 配合物[Ru(phen)₂TPPZ]^2＋和[Ru(phen)₂CImP]^2＋均可以与Zn^2＋形成双核配合物[Ru(phen)₂(TPPZ)Zn]^4＋和[Ru(phen)₂(CImP)Zn]^4＋, 配合物的荧光减弱. 与DNA作用后, 配合物仍可以与Zn^2＋配位形成双核配合物, 但[Ru(phen)₂(TPPZ)Zn]^4＋保持插入模式与DNA作用, 配合物的荧光减弱. 而[Ru(phen)₂(CImP)Zn]^4＋与DNA则由沟面结合改为插入结合, 配合物的荧光增强.     

Ruthenium(II) complexes of 6,7-dicyanodipyridoquinoxaline: synthesis, luminescence studies, and DNA interaction

The hexaflurophosphate and chloride salts of a series of ruthenium(II) complexes incorporating a new dipyridophenazine-based ligand, dicnq (6,7-dicyanodipyrido[2,2-d:2',3'-f]quinoxaline), are synthesized in good-to-moderate yields. These mono ([Ru(phen)2(dicnq)]2+; phen = 1,10-phenanthroline), bis ([Ru(phen)(dicnq)2]2+), and tris ([Ru(dicnq)3]2+) complexes are fully characterized by elemental analysis, infrared, FAB-MS, 1H NMR, and cyclic voltammetric methods. Results of absorption titration and thermal denaturation studies reveal that these complexes are moderately strong binders of calf-thymus (CT) DNA, with their binding constants spanning the range (1-3) x 10(4) M-1. On the other hand, under the identical set of experimental conditions of light and drug dose, the DNA (pBR 322)-photocleavage abilities of these ruthenium(II) complexes follow the order [Ru(phen)2(dicnq)]2+ > [Ru(phen)(dicnq)2]2+ > [Ru(dicnq)3]2+, an order which is the same as that observed for their MLCT emission quantum yields. Steady-state emission studies carried out in nonaqueous solvents and in aqueous media with or without DNA reveal that while [Ru(dicnq)3]2+ is totally nonemissive under these solution conditions, both [Ru(phen)2(dicnq)]2+ and [Ru(phen)(dicnq)2]2+ are luminescent and function as "molecular light switches" for DNA. Successive addition of CT DNA to buffered aqueous solutions containing the latter two complexes results in an enhancement of the emission in each case, with the enhancement factors at saturation being approximately 16 and 8 for [Ru(phen)2(dicnq)]2+ and [Ru(phen)(dicnq)2]2+, respectively. These results are discussed in light of the relationship between the structure-specific deactivations of the MLCT excited states of these metallointercalators and the characteristic features of their DNA interactions, and attempts are made to compare and contrast their properties with those of analogous dipyridophenazine-based complexes, including the ones reported in the preceding paper.     

不同配体对钌多吡啶配合物与DNA的作用和荧光性质的影响

Two polypyridyl ligands DCHIP (2-hydro-3，5-dichlorophenyl-imidazo[4，5-f][1，10] phenanthroline)，MDHIP(2，4-dihydrophenyl-imidazo[4，5-f][1，10]phenanthroline) and their ruthenium(Ⅱ) complexes [Ru(phen)₂MDHIP]²⁺ and [Ru(phen)₂DCHIP]²⁺ were prepared. Their DNA-binding properties were studied by spectroscopic methods and viscosity measurements. The results indicated that the complexes both bound to DNA by partial intercalation mode， but [Ru(phen)₂DCHIP]²⁺ exhibited stronger binding affinity for DNA than [Ru(phen)₂MDHIP]²⁺ due to the different planarities and steric effects of ligands. On the other hand， after binding to DNA， the fluorescence intensity of [Ru(phen)₂MDHIP]²⁺ decreased， while the fluorescence intensity of [Ru(phen)₂ DCHIP]²⁺ increased.     

Comparison of the binding stoichiometries of positively charged DNA-binding drugs using positive and negative ion electrospray ionization mass spectrometry

Positive and negative ion electrospray ionization (ESI) mass spectra of complexes of positively charged small molecules (distamycin, Hoechst 33258, [Ru(phen)2dpq]Cl2 and [Ru(phen)2dpqC]Cl2) have been compared. [Ru(phen)2dpq]Cl2 and [Ru(phen)2dpqC]Cl2 bind to DNA by intercalation. Negative ion ESI mass spectra of mixtures of [Ru(phen)2dpq]Cl2 or [Ru(phen)2dpqC]Cl2 with DNA showed ions from DNA-ligand complexes consistent with solution studies. In contrast, only ions from free DNA were present in positive ion ESI mass spectra of mixtures of [Ru(phen)2dpq]Cl2 or [Ru(phen)2dpqC]Cl2 with DNA, highlighting the need for obtaining ESI mass spectra of non-covalent complexes under a range of experimental conditions. Negative ion spectra of mixtures of the minor groove binder Hoechst 33258 with DNA containing a known minor groove binding sequence were dominated by ions from a 1:1 complex. In contrast, in positive ion spectra there were also ions present from a 2:1 (Hoechst 33258: DNA) complex, suggesting an alternative binding mode was possible either in solution or in the gas phase. When Hoechst 33258 was mixed with a DNA sequence lacking a high affinity minor groove binding site, the negative ion ESI mass spectra showed that 1:1 and 2:1 complexes were formed, consistent with existence of binding modes other than minor groove binding. The data presented suggest that comparison of positive and negative ion ESI-MS spectra might provide an insight into various binding modes in both solution and the gas phase.     

Molecular modeling of the binding mode of chiral metal complexes △- and (A)-[Co(phen)2dppz]3+ with B-DNA

Molecular modeling methods have been applied to the structural characterization of the interaction between chiral metal complexes [Co(phen)2dppz]3+ (where phen = 1, 10-phenanthroline, dppz = dipyrido[3,2-a: 2′, 3′-c]phenazine) and the oligonucleotide (B-DNA fragment). The natures of two kinds of the binding modes, which are currently intense controversy, have been explored. Barton proposed that there is enantio-selective DNA binding by the octahedral complexes and intercalative access by these complexes from the major groove; but Norden suggested that both enantiomers bind extremely strongly to DNA from the minor groove without any noticeable enantio-selectivity. Our results support and extend structural models based upon Norden's studies, and conflict with Barton's model.     

Ruthenium(II) complexes of redox-related, modified dipyridophenazine ligands: synthesis, characterization, and DNA interaction

The synthesis, spectral characterization, and electrochemical properties of [Ru(phen)2(qdppz)]2+, which incorporates a quinone-fused dipyridophenazine ligand (naphtho[2,3-a]dipyrido[3,2-h:2',3'-f]phenazine-5,18-dione, qdppz), are described in detail. Chemical or electrochemical reduction of [Ru(phen)2(qdppz)]2+ leads to the generation of [Ru(phen)2(hqdppz)](2+)--a complex containing the hydroquinone form (hqdppz = 5,18-dihydroxynaphtho[2,3-a]-dipyrido[3,2-h:2',3'-f]phenazine) of qdppz. Absorption and viscometric titration, thermal denaturation, topoisomerase assay, and differential-pulse voltammetric studies reveal that [Ru(phen)2(qdppz)]2+ is an avid binder of calf-thymus DNA due to a strong intercalation by the ruthenium-bound qdppz, while [Ru(phen)2(hqdppz)]2+ binds to DNA less strongly than the parent "quinone"-containing complex. DNA-photocleavage efficiencies of these complexes also follow a similar trend in that the MLCT-excited state of [Ru(phen)2(qdppz)]2+ is more effective than that of [Ru(phen)2(hqdppz)]2+ in cleaving the supercoiled plasmid pBR 322 DNA (lambda exc = 440 +/- 5 nm), as revealed by the results of agarose gel electrophoresis experiments. The photochemical behaviors of both the quinone- and hydroquinone-appended ruthenium(II) complexes in the presence of DNA not only provide valuable insights into their modes of binding with the duplex but also lead to detailed investigations of their luminescence properties in nonaqueous, aqueous, and aqueous micellar media. On the basis of the results obtained, (i) a photoinduced electron transfer from the MLCT state to the quinone acceptor in Ru(phen)2(qdppz)]2+ and (ii) quenching of the excited states due to proton transfer from water to the dipyridophenazine ligand in both complexes are invoked to rationalize the apparent lack of emission of these redox-related complexes in the DNA medium.     

Synthesis and spectroscopic DNA binding studies of homoleptic and heteroleptic ruthenium(II) complexes with imidazo[4,5-f] [1,10]phenanthroline or its derivatives

Two series of new complexes, [Ru(phen)2L]2+ and [RuL3]2+, where phen = 1,10-phenanthroline, and L denotes imidazo[4,5-f][1,10]phenanthroline (IP) or 2-(4-R-phenyl)imidazo[4,5-f][1,10]phenanthroline(PIP, R = H; HOP, R = –OH; MOP, R = –OMe; DMNP, R = NMe2; CLP, R = Cl; NOP, R = NO2), were synthesized and characterized. Their binding to calf thymus DNA was investigated using electronic absorption and emission spectroscopy. [Ru(IP)3]2+ and each [Ru(phen)2 L]2+ showed dramatic absorption hypochromism and bathochromicity, as well as steady-state emission intensity and excited-state lifetime enhancements {except nonluminescent [Ru(phen)2NOP]2+} associated with the presence of DNA, inferring that they bind to DNA by intercalation. These phenomena were not observed for [RuL3]2+ type complexes (except L = IP), indicating that they bind to DNA at most through electrostatic interactions.     

Molecular modeling of the binding mode of chiral metal complexes A- and A-[Co(phen)_2dppz]~(3 ) with B-DNA

Molecular modeling methods have been applied to the structural characterization of the interaction between chiral metal complexes [Co(phen)2dppz]3 (where phen = 1, 10-phenanthroline, dppz = dipyrido[3,2-a: 2', 3'-c]phenazine) and the oligonucleotide (B-DNA fragment). The natures of two kinds of the binding modes, which are currently intense controversy, have been explored. Barton proposed that there is enantio-selective DMA binding by the octahedral complexes and intercalative access by these complexes from the major groove; but Norden suggested that both enantiomers bind extremely strongly to DNA from the minor groove without any noticeable enantio-selectivity. Our results support and extend structural models based upon Norden's studies, and conflict with Barton's model.     

Interaction of rac-[Cu(diimine)3]2+ and rac-[Zn(diimine)3]2+ complexes with CT DNA: effect of fluxional Cu(II) geometry on DNA binding, ligand-promoted exciton coupling and prominent DNA cleavage

The complexes [Cu(phen)(3)](ClO(4))(2) 1, [Cu(5,6-dmp)(3)](ClO(4))(2) 2, [Cu(dpq)(3)](ClO(4))(2) 3, [Zn(phen)(3)](ClO(4))(2) 4, [Zn(5,6-dmp)(3)](ClO(4))(2) 5 and [Zn(dpq)(3)](ClO(4))(2) 6, where phen = 1,10-phenanthroline, 5,6-dmp = 5,6-dimethyl-1,10-phenanthroline and dpq = dipyrido[3,2-d:2',3'-f]quinoxaline, have been isolated, characterized and their interaction with calf thymus DNA studied by using a host of physical methods. The X-ray crystal structures of rac-[Cu(5,6-dmp)(3)](ClO(4))(2) and rac-[Zn(5,6-dmp)(3)](ClO(4))(2) have been determined. While 2 possesses a regular elongated octahedral coordination geometry (REO), 5 possesses a distorted octahedral geometry. Absorption spectral titrations of the Cu(II) complexes with CT DNA reveal that the red-shift (12 nm) and DNA binding affinity of 3 (K(b), 7.5 x 10(4) M(-1)) are higher than those of 1 (red-shift, 6 nm; K(b), 9.6 x 10(3) M(-1)) indicating that the partial insertion of the extended phen ring of dpq ligand in between the DNA base pairs is deeper than that of phen ring. Also, 2 with a fluxional Cu(II) geometry interacts with DNA (K(b), 3.8 x 10(4) M(-1)) more strongly than 1 suggesting that the hydrophobic forces of interaction of 5,6 methyl groups on the phen ring is more pronounced than the partial intercalation of phen ring in the latter with a static geometry. The DNA binding affinity of 1 is lower than that of its Zn(ii) analogue 4, and, interestingly, the DNA binding affinity 2 of with a fluxional geometry is higher than that of its Zn(II) analogue 5 with a spherical geometry. It is remarkable that upon binding to DNA 3 shows an increase in viscosity higher than that the intercalator EthBr does, which is consistent with the above DNA binding affinities. The CD spectra show only one induced CD band on the characteristic positive band of CT DNA upon interaction with the phen (1,4) and dpq (3,6) complexes. In contrast, the 5,6-dmp complexes 2 and 5 bound to CT DNA show exciton-coupled biphasic CD signals with 2 showing CD signals more intense than 5. The Delta-enantiomer of rac-[Cu(5,6-dmp)(3)](2+) 2 binds specifically to the right-handed B-form of CT DNA at lower ionic strength (0.05 M NaCl) while the Lambda-enantiomer binds specifically to the left-handed Z-form of CT DNA generated by treating the B-form with 5 M NaCl. The complex 2 is stabilized in the higher oxidation state of Cu(II) more than its phen analogue 1 upon binding to DNA suggesting the involvement of electrostatic forces in DNA interaction of the former. In contrast, 3 bound to DNA is stabilized as Cu(I) rather than the Cu(II) oxidation state due to partial intercalative interaction of the dpq ligand. The efficiencies of the complexes to oxidatively cleave pUC19 DNA vary in the order, 3> 1 > 2 with 3 effecting 100% cleavage even at 10 microM complex concentration. However, interestingly, this order is reversed when the DNA cleavage is performed using H(2)O(2) as an activator and the highest cleavage efficiency of 2 is ascribed to its electrostatic interaction with the exterior phosphates of DNA.