Study on Triplex DNA by Use of Molecular “Light Switch“ Complex of Ru(phen)2(dppx)^2

A new method for the study of triplex DNA is established according the fluorescence enhancement of molecular “Light Switch“ complex of Ru(phen)2(dppx)^2 when it intercalate into triplex DNA.Because the fluorescence intensity of Ru(phen)2(dppx)^2 bonded to triplex DNA is in ths case higher than that bonded to duplex DNA in certain range of DNA concentration,the method is much more sensitive than other methods reported previously.     

Study on Triplex DNA by Use of Molecular “hight Switch”Complex of Ru(phen)_2(dppx)~(2+)

StudiesonthestructuraldiversityofDNAhavedrawnmuchattentioninrecentyears.Felsenfeldetal.1firstproposedthestructureoftriple-helixRNAandsuccessfullysynthesizedakindoftriplexRNA.Mirkinandcoworkers2discoveredatriplexDNA(H-DNA)inanacidsolutionofplasmid.Inthesameyear,Dervanetal.3attachedaman-madesingle-strandedDNAtorealgeneDNAandlocallyformedakindofinterstrandtriplex.ThiscouldbeusedtoinciseduplexDNAinaprecisemanner,showinghighpotentialforapplicationsasagenecontroller,man-maderestrictionend…     

Ru(bipy)_2(dppz)~(2+)与DNA相互作用的光谱研究

利用荧光和紫外可见吸收光谱研究了 Ru( bipy) 2 ( dppz) 2 +与 DNA之间的插入键合作用。结果表明 ,Ru( bipy) 2 ( dppz) 2 +是通过 dppz配体插入到 DNA的双螺旋结构中。而且 ,一定浓度的 Fe( CN) 4 - 6 和 Na Cl对 Ru( bipy) 2 ( dppz) 2 +- DNA复合物的荧光无猝灭作用 ,这一结果也证实了 Ru( bipy) 2 ( dppz) 2 +和 DNA之间的插入键合作用     

Ru（bipy）2（dppz）^2＋ 与DNA相互作用的光谱研究

利用荧光和紫外可见吸收光谱研究了Ru(bipy)2(dppz)^2 与DNA之间的插入键合作用。结果表明,Ru(bipy)2(dppz)^2 是通过dppz要与体插入到DNA的双螺旋结构中。而且,一定浓度的Fe( CN)^4-6和NaCl对Ru(bipy)2(dppz)^2 －DNA复合物的 荧光无猝灭作用,这一结果也 证实了Ru(bipy)2(dppz)^2 与DNA之间的插入键合作用。     

Application of the Ru(bipy)2(dpp)2+ / C2O4 2− electrochemiluminescence reaction to the determination of phenol

The electrochemiluminescence (ECL) of the ruthenium di(2,2′-bipyridine)- (4,7-diphenyl-1,10-phenanthroline) complex (Ru-bipy-dpp) produced on a glassy carbon electrode was studied by cyclic voltammetry. The anodic oxidation of Ru-bipy-dpp produces ECL in the presence of oxalate in oxygen-free aqueous solutions. Threefold ECL efficiencies were obtained for Ru-bipy-dpp relative to Ru(bipy)₃ as a standard. The ECL of Ru-bipy-dpp is quenched by both oxygen and phenol. The luminescence intensity was proportional to the concentration of phenol in the range of 5–100 μM. At a phenol concentration of 100 μM, the ECL of Ru-bipy-dpp peaking at 597 nm was completely quenched. Correspondence: Dan Xiao, College of Chemistry and Chemical Engineering, Sichuan University, Chengdu 610065, P.R. China     

A Novel Optical Properties of Molecular “Light Switch” and its Analytical Application

Because of the high affinity (Ka≥ 10^6 L mol^-1) between Ru(phen)2(dppz)^2 and DNA, the adding of DNA in the solution of Ru(phen)E(dppz)^2 -SDS makes the dissociation of Ru(phen)E(dppz)^2 -SDS, and results in decrease of the resonance light scattering (RLS) signals andincrease of the absorbance. Based on this, a novel method is proposed for DNA assay.     

Ru(bipy)2+3/Ru(phen)2+3-C2O2-4-CeⅣ化学发光反应动力学模型的研究

根据Ru(bipy)2+3/Ru(phen)2+3-C2O2-4-CeⅣ(bipy=2,2′-联吡啶,phen=1,10-邻菲咯啉)化学发光反应建立了该化学发光反应的动力学模型,根据模型计算出该反应的发光强度-反应时间曲线上升及下降阶段的反应速率常数、发光强度最大值及其出现的时间等.发光强度最大值及发光强度-反应时间曲线下的面积均可用于定量分析.     

Ru(bipy)2+3-Ce(Ⅳ)化学发光体系检测速尿的研究

基于速尿对三(2, 2′-联吡啶)钌(Ⅱ)[Ru(bipy)2+3]-Ce(Ⅳ)化学发光体系发光的增强作用,建立了一种化学发光直接检测速尿的新方法.在优化的实验条件下,该方法的线性范围和检出限分别为5.0×10-3～1.5 mg/L和4.0×10-3 mg/L,对含速尿0.50 mg/L的溶液平行测定11次,相对标准偏差(RSD)为5.0 %.将其应用于呋塞米片剂样品中速尿含量的测定,结果满意.     

Determination of the Absolute Configuration of the (−)-Me(EtO)(HO)P-Mo(CO)5 Coordination Complex by Decomplexation of the Organophosphorus Ligand

Abstract

The resolution of a chiral coordination complex (1) was recently carried out in our laboratory, and some stereochemical transformations of the resolved specie have been reported (L. P. Reiff, L. J. Szafraniec, D. I. Rossman and H. S. Aaron, Inorg. Chem. 1986, 25, 0000). Decomplexation studies of its organophosphorus ligand have now been carried out. Thus, treatment of the (?)-1 complex with two molar equivalents of triphenylphosphine yields (+)-ethyl methylphosphinate (2), considerably racemized, however, due to the 120°C temperature required to achieve decomplexation. To determine its optical purity and its absolute configuration, the latter was converted into the known S-(?)-3 thioic acid and S-(?)-4 methyl ester, respectively. While the method does not appear to be of synthetic utility for the preparation of optically active (decomplexed) organophosphorus species, the absolute configuration of the S-(?)-1 coordination complex is established on the basis of these stereochemical relationships.     

Ru(Ⅱ) Bipyridyl Complex and TiO2 Nanocomposite Based Biomolecule-free Photoelectrochemical Sensor for Highly Selective Determination of Ultra-trace Hg^2+ in Aqueous Systems

A biomolecule-free photoelectrochemical(PEC) probe(denoted as Ru-1) was designed, synthesized and coupled with TiO2 nanoparticles(NPs) for the highly sensitive and selective PEC detection of Hg^2+, a model analyte with hypertoxicity to both human health and ecosystem. The probe Ru-1 was designed with Ru(Ⅱ) bipyridyl complex as the chromophore, thiocyanate ligand as the recognition unit, and carboxylate group as the linkage site to connect Ru-1 to TiO2 nanoparticles. Under irradiation, Ru-1 shows strong affinity to TiO2 and good photophysical properties of strong visible light absorption, slow electron-hole(e-h^+) recombination, and fast photoelectron injection to TiO2 nanoparticles via the bridge of 4-(2,2-bipyridin)-4-yl-thiophene moiety. However, the specific coordination of Hg^2+ with Ru-1 via the thiol moiety in the thiocyanate enlarges the band gap of tlie complex and reduces the photocurrent significantly. The synergistic interaction between TiO2 nanoparticles and the Ru-1 complex led to a selective PEC sensing strategy for Hg^2+ detection. Detectable linear ranges from 10^-12 g/mL to 10^-7 g/mL and from 10^-7g/mL to 10^-3 g/mL were obtained without the interference from possibly co-existed metal ions. The good analytical performances indicate the chemical probe based biomolecule-free PEC platform may offer a new route for the detection of biologically and environmentally important small molecules.     

Asymmetric Transfer Hydrogenation of Ketone Catalyzed by Novel Ru(Ⅱ)-Chiral Sulfonamide Complex

Asymmetriccatalytictransferhydrogenation,duetoitspracticalmethodforthestereoselectivesynthesisofchiralalcohols,attractsmuchattentionandhasbeenextensivelystudied.Themostwellkngwnligandsischirall,2-diaminewithC2symmetry'.Butthetridentatenitrogenligandhavingquinolinegrouphasrelativelybeenneglected.Wehaveinvestigatedsulfonamidederivativesintheuseofenantioselectivetransferhydrogenationofketone2.Inthispaper,wereporttwonewchiralRu(II)sulfonamidecatalystspreparedicsitufromchiralsulfonamideand[RuCI=…     

Studies on the Interaction of Ru(Ⅱ) Polypyridyl Mixed-ligand Complexes and DNA by Viscosity Measurement

The interaction of transition metal polypyridyl coordination compounds with DNA has been extensively studied in the past few years^[1]. Li the case of double stranded DNA, some coordination compounds may bind in the major groove with one ligand inserting between two base pairs DNA. The viscosity studies provide a strong argument for intercalation^[2].     

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。     

Molecular modeling of the binding mode of chiral metal complexes δ- and ∧-[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’ model.     

The Effect of Ni2+ and Cu2+ on the Photocatalytic Degradation of Dyes by the Chitosan–TiO2 Complex

The present research combines biosorption and photocatalysis in a functional TiO(2)-immobilized chitosan adsorbent (CTA). CTA can degrade organic pollutants and adsorb metal ions simultaneously. Target pollutants were dyes of cationic (rhodamine B, Rh.B) and anionic (methyl orange, MO) nature, with Ni(2+) and Cu(2+) selected as heavy metals. The presence of Ni(2+) or Cu(2+) improved the degradation ability of CTA for MO, but inhibited the degradation of Rh.B, with Cu(2+) exhibiting stronger effects than Ni(2+). There was no significant difference in CTA activity when the metal ions were pre-adsorbed or when they coexisted in the solution with the organic dyes. Protons in the reaction system affected the degradation performance in a similar way for Ni(2+) and Cu(2+) leading to a different effect on the degradation for MO and Rh.B. An X-ray photoelectron spectroscopy analysis of the binding energies of the metal ions on the surface in the presence of the cationic or anionic dyes explained the different behaviors. Since anionic and cationic dyes possess chromogenic groups of different charges, they adversely affect the production of OH? radicals when coexisting with Cu(2+) or Ni(2+).     

Synthesis and Molecular Structure of Binuclear Tin(IV) Complex Bridged by Terephthalate Anion

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Off-on-off Luminescent Switching of a Novel Ru(II) Complex

There has been explosive interest in the synthesis and applications of novel Ru(II) polypyridyl complexes with respect to molecular sensors1,2, switches3, and sensitizers of Gr鋞zel solar cells based on nanocrystalline TiO24. Here we report a novel Ru(II) complex, which can serve as pH-induced remarkable off-on-off luminescent switch. Scheme 1 The acid-base equilibria of the complex UV-vis absorption and emission spectroscopic pH titration experiments of the Ru complex wit…     

Asymmetric Michael Reaction of Malononitrile Catalyzed by Chiral Ru(Ⅱ) Complex and Achiral Base

Michael addition reactions represent one of the most important carbon-carbon bond forming reactions in modern synthetic organic chemistry. [1 ～3] We achieved catalytic enantioselective Michael addition reactions of malononitrile with chiral vicinal diamine-Ru(Ⅱ) complex in the presence of achiral base. High yields and moderate ee were observed.     

Indirect Spectrophotometric Determination of Sulphide with the Complex of Cd(Ⅱ)-5-Br-PADAP-CPB

ampornoNTh6SpetemofCd-&Br-PADAPis~SenSitbo(s=l.4Xlotl.mol-l.CIn-'),ltwaSuSUaIly~todet6rInintal-[1],butitedotodboboeofitsWatertheOlUbuny,italSocanbeodtodetermineodboinwater8oforbobytheuseOfnthe8ufor[2J.Intthework,catiOnisuthetantwasedinCd-5Br-PADAPsy8tem,itssensitivityndthenduzn~tionwavelengthhaofthecomplexcanbeincred2O%and2onInreSpeivelybycom-P8tisonwithliteratureL2J.TheapplicaiOnOfdsterwicomplexspstemtosperOPhOtomethedeterminaiOnofsulPhidefromitseboOfdecreaseinabeorPtboonth…     

Multiple pathways for benzyl alcohol oxidation by Ru(V)═O3+ and Ru(IV)═O2+

Significant rate enhancements are found for benzyl alcohol oxidation by the Ru(V)═O(3+) form of the water oxidation catalyst [Ru(Mebimpy)(bpy)(OH(2))](2+) [Mebimpy = 2,6-bis(1-methylbenzimidazol-2-yl)pyridine; bpy = 2,2'-bipyridine] compared to Ru(IV)═O(2+) and for the Ru(IV)═O(2+) form with added bases due to a new pathway, concerted hydride proton transfer (HPT).