[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⁺).     

一种新型Zn2＋近红外荧光探针的研究

Zn^2＋是多种酶和转录因子的必要成分, 在生物体内起着重要的作用, 检测Zn²⁺具有十分重要的生物学意义. 我们合成了一种新型近红外荧光探针TAEA-IR-780, 该探针通过配位作用与Zn^2＋结合后, 荧光显著增强. 通过质谱和氢谱对该探针进行了表征, 并探讨了pH值、其它金属离子对Zn^2＋检测的影响. 该探针的激发波长为683 nm, 发射波长为750 nm, 可避免对生物活体的损伤, 同时生物体内常见的金属离子对其干扰较小. 该探针对Zn^2＋的检测下限达1.0× 10^－9 mol•L^－1, 具有较高的检测灵敏度.     

一种同时分辨识别Zn2+和F-离子的双功能探针

由8-甲酰基-7-羟基香豆素与碳酰肼经一步缩合反应可制得探针1。研究发现,探针1对Zn²⁺和F^-离子均呈现荧光增强和比率比色的高灵敏和高选择性响应,检出限低至10^-8 mol·L^-1。通过光谱、ITC、¹H NMR滴定及质谱分析,详细地研究了探针与离子形成的配合物性质。在不同的介质中,探针不仅同时表现出对金属阳离子Zn²⁺和对阴离子F^-的识别,而且吸收和发射波长均有显著的差异：1-Zn²⁺配合物的最大吸收波长为360 nm,而1-F^-配合物为400 nm;1-Zn²⁺配合物的荧光激发和发射波长分别为360和454 nm,而1-F^-配合物分别为400和475 nm。此外,探针1还能应用于活体PC3细胞中Zn²⁺的荧光成像。     

2,5-噻吩二甲酸与菲咯啉构筑的稀土配合物:晶体结构，荧光性质和对Cu2+离子的荧光传感

稀土硝酸盐和2,5-噻吩二甲酸与菲咯啉在水热反应条件下合成了3个新的配合物,[Ln（2,5-tdc）_1.5（phen）（H₂O）]_n（Ln=Gd（1）,Tb（2）,Dy（3）;2,5-tdc=2,5-噻吩二甲酸根,phen=菲咯啉）。通过X射线单晶衍射确定了它们的晶体结构。配合物1~3为同构的2D网络结构。配合物1在340 nm激发下出现最大发射中心位于366和387 nm的宽峰,可归属于配体的π^*-π跃迁发射。配合物2在365 nm紫外灯照射下发绿光,其荧光发射光谱中出现了4个尖峰,位于491、545、588和620 nm处,对应于Tb³⁺的⁵D₄→⁷F_J（J=6~3）跃迁。配合物2的荧光寿命显示为单指数衰减,其值为（0.123±0.005）ms。配合物3的发射光谱中出现了2个尖峰,位于482和575 nm处,分别对应于Dy³⁺的⁴F_5/2→⁶H_15/2和⁴F_5/2→⁶H_13/2跃迁。另外,研究了配合物2的荧光传感能力,该配合物可作为荧光探针检测水溶液中的Cu²⁺离子。     

一个特殊的多吡啶钴(Ⅲ)配合物

本文介绍一五胺配合物［Ｃｏ（ｔｅｒｐｙ）（ｂｐｙ）Ｃｌ］~（２＋）,三元胺是２,２′：６′,２″三联吡啶,二元胺是２,２′－联吡啶,此配合物结构特殊在于分子中没有任何酸性氢。利用其考察非碱催化水解过程中发现,该配合物的水解速率出人意料地快。这个取代反应可能是一氧化还原过程。     

新型双核配合物的形成及荧光性质研究

利用光谱学方法研究了[Ru(bpy)2TPPHZ]2+(TPPHZ=四吡啶[3,2-a: 2',3'-c: 3",2"-h: 2'",3'"-j]吩嗪)和[Ru(bpy)2ODHIP]2+(ODHIP=3,4-二羟基-咪唑并[4,5-f][1,10]邻菲咯啉)与Ni2+的配位情况及配位后的荧光性质变化, 探讨了配合物与Ni2+配位形成双核配合物后与DNA的作用机制变化. 结果表明, [Ru(bpy)2TPPHZ]2+和[Ru(bpy)2ODHIP]2+均可与Ni2+配位, 形成双核配合物[Ru(bpy)2(TPPHZ)Ni]4+和[Ru(bpy)2(ODHIP)Ni]4+, 配合物的荧光强度随着Ni2+浓度的增加而减弱. 与DNA作用后, 配合物仍可与Ni2+配位形成双核配合物, [Ru(bpy)2(TPPHZ)Ni]4+的荧光几乎完全消失, 同时配合物与DNA保持插入模式作用, 而配合物[Ru(bpy)2(ODHIP)Ni]4+与DNA的作用则由沟面结合改为插入结合, 同时配合物的荧光减弱.     

Zn2+对土壤微生物碳、呼吸强度的影响

Zn是典型的人类活动源元素之一，工业化进程加剧了Zn对农田生态系统污染的威胁犤１犦。最初，重金属是否污染判断标准采用X＋２S（X为该元素背景值，S为标准偏差）犤２犦，国际通用土壤质量标准界定之后，将生物量下降６０％作为重金属元素的临界浓度犤３犦。一些研究表明，Cu、Pb、Cd、Hg等进入土壤之后，微生物群落多样性发生改变犤４犦，导致微生物生物量和呼吸速率降低或显著增加犤５犦，酶的活性受严重损害犤６犦，微生物生态参数Cmic／Corg降低，代谢熵qCO２则明显升高犤７犦。对Zn２＋的研究侧重于生物毒理作用犤８犦，Zn２＋…     

钴(Ⅲ)多吡啶配合物与DNA对接性质的理论研究

采用密度泛函理论,在真空和溶液中对两个钴多吡啶配合物的几何结构进行了优化,结果表明在溶液中优化的几何结构和实验结果吻合较好.以在溶液中优化的几何结构为基础,运用对接软件Dock 6.0,把这两个钴(Ⅲ)多吡啶配合物对接到DNA碱基对中,从总体模型上,研究钴(Ⅲ)多吡啶配合物与DNA碱基对作用的部位,并详细解释了配合物1与DNA键合常数大于配合物2的原因.     

外源Cu2+与烟草CuZnSODⅢ的相互作用

In this paper， we have studied the interaction of CuZnSODⅢ and Outer-Copper， enzyme activity experiments expressed that 0.1mmol·L^-1 Cu²⁺ addition reduced the enzyme activity sharply， but this reduced action had not been found for the additions of 0.1mmol·L^-1 1∶1 Cu²⁺ and Zn²⁺， and 0.1mmol·L^-1 Zn²⁺， respectively. This was due to the Cu²⁺ exchanged the Zn²⁺ in CuZnSODⅢ，and it was proved by the experiment of determination of metal content. Meanwhile， the static fluorescence quenching mechanism revealed the exist of molecular complex of CuZnSOD with Cu²⁺. The binding constant was obtained from lineweaver-burk and double-lg plot. The distance of active site to Trp is about 2.83nm， was calculated according to F?rster theory.     

用于痕量监测Zr4+、Cr2O72-、Fe3+、HPO42-和指纹识别的功能化Eu3+/Tb3+配位聚合物荧光探针的构筑

采用芳香族π共轭及含氮原子有机连接剂,合成同构铽、铕发光配位聚合物(CPs){[Eu(PLIA)_1.5(H₂O)₂]·H₂O}_n (1)和{[Tb(PLIA)_1.5(H₂O)₂]·H₂O}_n (2),其中H₂PLIA=5-((吡啶-4-基甲基)氧基)苯-1,3-二甲酸。对合成的配合物进行了结构测定、表征和荧光痕量识别实验研究。2个同构配合物具有理想的三维框架结构,π…π堆积及氢键等弱相互作用增强了其化学稳定性;表征显示配位聚合物1和2具有良好的荧光性质、结晶性、热力学稳定性及结构完整性,可作为荧光传感的材料。1和2对水溶液中的Zr⁴⁺、Cr₂O₇^2-和Fe³⁺、HPO₄^2-具有选择性好、灵敏度高的荧光识别能力,其检出限分别为0.139 μmol·L^-1(1,Zr⁴⁺)、0.626 μmol·L^-1(1,Cr₂O₇^2-)、0.430 μmol·L^-1(2,Fe³⁺)、1.36 μmol·L^-1(2,HPO₄^2-)。探究了1和2作为探针的荧光猝灭机理。更有趣的是,1和2具有指纹识别性能,其荧光指纹纹路清晰连贯,细节明显,可被清晰观察。     

钌(II)多吡啶配合物的合成、荧光性质及与脱氧核糖核酸DNA的 作用机制研究

设计合成含多个配位中心的多吡啶配体ODCIP (3,4-二氯基苯并咪唑并[4,5-f][1,10]邻菲咯啉)及其钌(II)多吡啶配合物[Ru(bpy)2ODCIP]2＋. 运用元素分析、红外光谱、核磁谱和质谱对配体及配合物进行结构表征. 利用紫外吸收光谱、荧光光谱和粘度法研究了[Ru(bpy)2ODCIP]2＋与DNA(脱氧核糖核酸)的作用机制、与Co2＋配位后与DNA的作用机制及其荧光变化情况. 结果表明[Ru(bpy)2ODCIP]2＋与DNA通过部分插入模式作用, [Ru(bpy)2ODCIP]2＋与Co2＋配位形成的双核配合物[Ru(bpy)2(ODCIP)Co]4＋也能与DNA插入结合. 进一步利用稳态荧光发射光谱、荧光淬灭实验等方法研究了单核配合物[Ru(bpy)2ODCIP]2＋和双核配合物[Ru(bpy)2(ODCIP)Co]4＋的荧光性质.     

Graphene quantum dots with Zn2+ and Ni2+ conjugates can cleave supercoiled DNA

Graphene quantum dots (GQDs), inheriting the superb property of graphene oxide, possess smaller lateral size and high biocompatibility, thus having potential in biomedical applications. We previously discovered that GQDs, combining with Cu²⁺ ions, could cleave DNA primarily through an oxidative pathway; yet, oxidative DNA cleavage is not practically preferred in biology. In this work, we explore the DNA cleavage ability of GQDs with Zn²⁺ and Ni²⁺. Zn²⁺ and Ni²⁺ alone are incapable of cleaving supercoiled DNA, but when combining with the GQDs, Zn²⁺ and Ni²⁺ exhibit DNA cleavage activity. However, the activity of these two systems is much lower than that of GQDs/Cu²⁺, and GQDs/Ni²⁺ is less active than GQDs/Zn²⁺. The functional mechanism of GQDs/Ni²⁺ and GQDs/Zn²⁺ is different from that of GQDs/Cu²⁺. The GQDs play a key role in the two systems; the redox inactive Zn²⁺ and Ni²⁺ ions assist to generate the oxidative species that eventually lead to the DNA cleavage. The current results together with our previous result indicate that GQDs together with metal ions can cleave supercoiled DNA, and their cleavage activities depend on the properties of metal ions: for redox active metal ions, metal ions play key roles, for redox inactive metal ions, GQDs are dominant.     

A New Luminescent Ruthenium(II) Polypyridine‐derived Dipicolylamine Complex as a Sensor for Cu2+ Ions

A chemo‐sensor [Ru(bpy)₂(bpy‐DPF)](PF₆)₂ ( 1 ) (bpy=2,2′‐bipyridine, bpy‐DPF=2,2′‐bipyridyl‐4,4′‐bis(N,N‐di(2‐picolyl))formylamide) for Cu²⁺ using di(2‐picolyl)amine (DPA) as the recognition group and a ruthenium(II) complex as the reporting group was synthesized and characterized successfully. It demonstrates a high selectivity and efficient signaling behavior only for Cu²⁺ with obvious red‐shifted MLCT (metal‐to‐ligand charge transfer transitions) absorptions and dramatic fluorescence quenching compared with Zn²⁺ and other metal ions.     

[Ru(bpy)_2tpphz]~(2+)与Zn~(2+)形成的双核配合物的荧光性质研究

近年来,钌多吡啶配合物与DNA的作用得到了比较广泛的研究,并且发展了一系列具有特定功能的钌配合物犤1犦。如传统的DNA分子光开关犤Ru(bpy)2dppz犦2+和犤Ru(phen)2dppz犦2+犤2,3犦(bpy=2,2'-联吡啶,phen=1,10-菲咯啉,dppz=二吡啶犤3,2-a:2',3'-c犦吩嗪)。这些配合物与DNA具有较强的结合力,在水溶液中几乎不发光,但在DNA存在下则有强烈荧光发出。这是由于配合物插入DNA的碱基对之后,保护了dppz的吡嗪环上的N原子,使其免受水分子的进攻从而导致配合物荧光的恢复。但是对于大多数的多吡啶钌配合物来讲,由于其自身较强的背景荧光或与DN…     

A highly selective visual and fluorescent sensor for Pb2+ and Zn2+ and crystal structure of Cu2+ complex based-on a novel single-armed Salamo-type bisoxime

A novel single-armed Salamo-type bisoximes (H₄L) has been designed and synthesised. An obvious colour change from yellow (H₄L) to pale pink (HL-Pb²⁺) which can be visually observed by the naked eye in visible light. H₄L can act as a fluorescent sensor for ratiometric recognition of Zn²⁺ with high selectivity and sensitivity. Crystallographic data of the [Cu(HL)(μ-OAc)Cu] reveals that the two Cu²⁺ ions are both penta-coordinated with square pyramidal geometries, and forms a 2D supramolecular plane structure by hydrogen bonding interactions.     

Comparison of Partial Least Squares Regression and H-Point Standard Addition Method for Simultaneous Spectrophotometric Determination of Zinc, Cobalt and Nickel by 1-(2-Pyridylazo)2-Naphthol in Micellar Media

Simultaneous spectrophotometric methods are described for the determination of Zn²⁺, Co²⁺ and Ni²⁺ by 1-(2-pyridylazo)2-naphthol (PAN) in micellar media, using absorbance correction-H-point standard addition method (HPSAM) and partial least squares (PLS) regression. The ligand and its metal complexes, i.e. Zn²⁺-PAN, Co²⁺-PAN and Ni²⁺-PAN, were made water-soluble by the neutral surfactant Triton X-100, and therefore extraction with organic solvents was no longer required. Formation of all of these complexes was complete within 10min at pH 9.2. The linear range was 0.1–1.5mgL^–1 for Zn²⁺, 0.1–2.0mgL^–1 for Co²⁺ and 0.1–2.0mgL^–1 for Ni²⁺. The relative standard deviation (RSD) for the simultaneous determination of 0.50mgL^–1 each of Zn²⁺, Ni²⁺ and Co²⁺ by applying the H-point standard addition method was 2.55%, 2.04% and 3.70%, respectively. The total relative standard error for applying the PLS method to 9 synthetic samples in the linear ranges of these metals was 1.8%. Interference effects of common anions and cations were studied, and both methods were applied to the simultaneous determination of Zn²⁺, Co²⁺ and Ni²⁺ in alloy samples.     

三齿多吡啶钴(II)配合物的合成、表征及其与DNA的相互作用研究

合成了两种三齿多吡啶钴(II)配合物 (A)和[Co(H₂Bzimpy)₂]Cl₂ (B), 用元素分析、IR对配合物的组成和结构进行了表征, 测定了配合物A的晶体结构. 用电子吸收光谱、荧光光谱、循环伏安法及凝胶电泳实验等方法研究了配合物与DNA的相互作用. 结果表明配合物A和B与小牛胸腺(CTDNA)的作用属部分插入和静电结合, 凝胶电泳实验表明配合物A在310 nm光辐射15 min, 可使超螺旋pBR322DNA断裂为开环缺口型和线型DNA.     

EPR studies of Cu2+ in tetraaqua-di(nicotinamide) Zn(II)-saccharinate single crystals

Electron paramagnetic resonance (EPR) studies of copper ions, Cu(II), as paramagnetic impurity in tetraaqua-di(nicotinamide) Zn(II)-saccharinates single crystals [Zn(nic)2(H2O)4](sac)2, have been investigated at ambient temperature. The detailed EPR analysis shows the only one site and the copper ion entered the lattice substitutionally in place of Zn(II). The spin-Hamiltonian parameters were obtained from the single crystal EPR analysis. By using the EPR data, molecular bonding coefficient and the Fermi contact interaction terms have been evaluated. Superhyperfine splittings were observed.