新型β-取代阳离子卟啉光敏剂合成及其与DNA相互作用

在5,10,15,20-四苯基卟啉及其金属配合物的β位引入阳离子型修饰基团溴化吡啶鎓盐, 得到β-[2-(6-吡啶溴化盐)己氧基]萘基-5,10,15,20-四苯基卟啉及其Cu(II), Ni(II), Zn(II)配合物. 通过IR, UV, ¹H NMR, MS以及元素分析对新化合物进行了结构表征. 作为光动力治疗光敏剂与pBR322质粒DNA的相互作用研究表明, 它们对DNA具有良好的光敏切割效果和结合能力, 通过与小牛胸腺DNA相互作用初步研究了它们与DNA的作用模式.     

含萘磺酰基大环多胺与Cu(II)和DNA作用的荧光性能研究

以1,4,7,10-四氮杂环十二烷(Cyclen)为原料,合成了含有萘磺酰基的大环多胺,其结构经1H NMR、MS、元素分析等表征。用荧光光谱法测定了大环多胺与Cu(II)在不同pH下的配位情况,研究了大环多胺激发和发射波长,配体浓度与吸光度的线性关系;Cu(II)、小牛胸腺嘧啶DNA对大环多胺荧光性能的影响。     

含四硫富瓦烯Schiff碱配体和配合物二阶非线性光学性质的密度泛函理论研究

采用密度泛函理论(DFT)B3LYP(UB3LYP)/6-31g*方法对含四硫富瓦烯Schiff碱配体和它的Fe(III/II),Co(II),Ni(III/II),Cu(II)配合物的极化率和二阶非线性光学(NLO)性质进行了研究,并对其中闭壳层分子采用含时密度泛函理论(TD-DFT)方法计算了电子光谱.结果表明:含四硫富瓦烯Schiff碱配体本身具有较大的二阶NLO系数,二价金属配合物二阶NLO系数与配体接近,三价金属配合物二阶NLO系数约为配体的30倍.金属配合物不同自旋多重度时其二阶NLO系数相差不大.结合配体和配合物的前线分子轨道分析可知,配体和二价金属配合物的二阶NLO系数主要是配体内的电荷转移(ILCT)的贡献,三价金属配合物既有ILCT又有金属与配体间电荷转移(MLCT),同时前线分子轨道能级差显著减小,因此它们的二阶NLO系数显著增大.     

大环多胺及其金属配合物与DNA的相互作用

本文综述了近年来基于大环多胺及其金属配合物与DNA相互作用的研究进展,着重介绍本课题组在有关单双核、多核以及功能化大环多胺衍生物及其金属配合物与DNA相互作用方面的研究和发现,并对其在化学核酸酶方面的应用进行了讨论。在单双核大环多胺衍生物方面,我们分别合成了以吡啶、苯环、咪唑、三氮唑为侧臂的单核大环多胺金属配合物,同时合成了以刚性桥相连的双核配合物和以柔性链相连的双核配合物。并研究这些单双核大环多胺与DNA的相互作用,发现以刚性链相连的双核大环多胺金属配合物具有很好的切割DNA的性质,可以在低浓度、短时间内切断DNA。在功能化大环多胺方面,我们合成了含有碱基、PNA单体、咪唑鎓盐、冠醚、二茂铁等功能化基团的大环多胺衍生物及金属配合物,并研究了其与DNA的相互作用。在多核大环多胺方面,我们合成了基于大环多胺的寡聚物,研究发现该类物质可与DNA形成复合物,从而有效地保护DNA免于酶解。     

新型水溶性手性Salen配合物的合成及性质研究

合成并表征了新型水溶性手性Salen 配体(R,R)-N,N’-二{4-[2-(三甲胺基)乙氧基]水杨醛}-1,2-环己二胺二高氯酸盐(L)及金属配合物ML [M＝Zn(II), Cu(II), Ni(II), Co(II), Fe(III), Mn(III)]. 讨论了手性配体L及配合物ZnL的电子光谱和圆二色光谱性质, 用UV-Vis光谱滴定和CD光谱滴定法研究了ZnL对手性氨基酸对映异构体的分子识别. 测定了主体ZnL与客体氨基酸轴向配位反应的配位数(n)、缔合常数(K)及热力学函数 测得缔合常数的大小顺序为KPhe＞KVal＞KThr. 研究发现反应是放热、熵减小的过程. 用凝胶电泳的方法初步研究了此类手性金属配合物在H2O2存在下对DNA的裂解作用.     

草酰胺桥联大环二羰四胺铜(Ⅱ)-钴(Ⅱ)异双核配合物的合成、结构、表征和电化学性质

合成了一种具有草酰胺桥联大环二羰四胺结构的Cu(Ⅱ)-Co(Ⅱ)异双核配合物,用红外光谱、电子光谱、摩尔电导、热重分析、室温磁矩、循环伏安等对其进行了表征. 初步推定Cu(Ⅱ)-Co(Ⅱ)异双核配合物具有草酰胺桥联大环二羰四胺结构. 室温磁矩测定表明,通过草酰胺桥联配体金属离子间有一定的反铁磁性自旋偶合作用. 循环伏安法测定了配合物的半波电位,实验表明,此类配合物能够稳定高价态Cu(Ⅲ),外延桥基配位对大环内腔Cu(Ⅱ)离子的氧化还原过程无影响. 单核配合物X射线晶体衍射研究表明,其为单斜晶系,空间群P21/c,a=0.738 61(15) nm,b=2.121 1(4) nm,c=0.952 50(19) nm,β=94.70(3)°,R1=0.051 3,wR2=0.117 7,Z=4. Cu(Ⅱ)处于大环四胺平面正方中心上方0.03 nm,并具有外延草酰胺桥.     

金属-血清白蛋白的结构研究II. Cu(II)-BSA和Ni(II)-BSA的四 方锥-四方平面 结构

本文用紫外光谱研究Cu(II)-BSA和Ni(II)-BSA配合物的结构随BSA浓度的变化,发现当浓度增大并>2×10^-^4～3×10^-^4mol.dm^-^3时,这两种配合物从五配位的四方锥构型转变成四配位的四方平面构型,首次提供了BSA的Asp羧基氧参与同Cu(II)和Ni(II)配位的证据。计算并讨论了Cu(II),Ni(II)和有关配体轨道的光学电负性。     

金属-血清白蛋白的结构研究II. Cu(II)-BSA和Ni(II)-BSA的四 方锥-四方平面 结构

本文用紫外光谱研究Cu(II)-BSA和Ni(II)-BSA配合物的结构随BSA浓度的变化,发现当浓度增大并>2×10^-^4～3×10^-^4mol.dm^-^3时,这两种配合物从五配位的四方锥构型转变成四配位的四方平面构型,首次提供了BSA的Asp羧基氧参与同Cu(II)和Ni(II)配位的证据。计算并讨论了Cu(II),Ni(II)和有关配体轨道的光学电负性。     

大环二羰四胺Ni(Ⅱ)单核和Ni(Ⅱ)-Cu(Ⅱ)双核配合物的合成、表征及电化学性质

合成了一种草酰胺桥联大环二羰四胺Ni(Ⅱ )单核配合物 ,并以此为母体合成了Ni (Ⅱ ) -Cu (Ⅱ )双核配合物 .用元素分析、红外光谱、差热分析、紫外光谱、摩尔电导以及循环伏安等测试手段对配合物进行了表征和电化学性质研究 .经分析 ,标题配合物具有草酰胺桥联结构 ,Ni(Ⅱ )处于平面正方场 ,Cu (Ⅱ )处于八面体场中 .循环伏安测试表明此类配合物能稳定Ni(Ⅲ ) .     

碘阴离子桥联的金属镍大环二聚体[(NiL)_2I](I_3)_3

利用 Ni II- I- Ni II联接单元合成并表征了四氮大环镍 (II)配合物二聚体 [(Ni L) 2 I](I3) 3,这里 L=5 ,7,7,1 2 ,1 4,1 4-六甲基 - 1 ,4,8,1 1 -四氮杂环十四 - 4 ,1 1 -二烯。 X射线晶体结构及光谱数据显示 [(Ni L) 2 I](I3) 3是三明治结构 ,对称中心为碘离子 ,两个大环配合物平面相互平行 ,整个组装体的对称性为 D4d。结构数据还表明使 Ni II- I- Ni II单元起稳定作用的主要是碘离子与金属离子间的静电作用 ,还有较弱的共价相互作用。在这种二聚体中 ,金属离子不仅作为大环配合物的中心原子 ,而且在 Ni II- I- Ni II单元中还作为碘阴离子的受体。 [(Ni L ) 2 I](I3) 3的变温紫外可见吸收光谱表明其分解温度约为 375 K。因为这种四氮大环金属配合物二聚体含碘离子一价及三价碘阴离子 ,故有可能在将太阳能转变为电能的光电化学电池中作为电解质而获得应用。     

聚醚桥连二异羟肟酸单核和双核过渡金属配合物催化PNPP水解

Two polyether bridged dihydroxamic acids and their mono-and binuclear manganese(Ⅱ), zinc(Ⅱ) complexes have been synthesized and employed as models to mimic hydrolase in catalytic hydrolysis of p-nitrophenyl picolinate (PNPP). The reaction kinetics and the mechanism of hydrolysis of PNPP have been investigated. The kinetic mathematical model for PNPP cleaved by the complexes has been proposed. The effects of the different central metal ion, mono-and binuclear metal, the pseudo-macrocyclic polyether constructed by polyethoxy group of the complexes, and reactive temperature on the rate for catalytic hydrolysis of PNPP have been examined. The results showed that the transition metal dthydroxamates exhibited high catalytic activity to the hydrolysis of PNPP, the catalytic activity of binuclear complexes was higher than that of mononuclear ones, and the pseudo-macrocyclic polyether might synergetically activate H20 coordinated to metal ion with central metal ion together and promote the catalytic hydrolysis of PNPP.     

Catalytic hydrolysis of phosphate diester （BNPP） and plasmid DNA by mononuclear macrocyclic polyamine metal complexes

The activities of the catalytic hydrolysis of phosphate diester(BNPP)[bis(p-nitrophenyl)phosphate diester]and plasmid DNA (pUC18)by mononuclear macrocyclic polyamine metal complexes have been investigated in this paper.The results showed that the highest activity in hydrolysis of BNPP was obtained with 1e-Zn(Ⅱ)complex(composed of lipophilic group)as catalyst.The hydrolysis rate enhancement is up to 3.64×10~4 fold.These metal complexes could effectively promote the cleavage of plasmid DNA(pUC18)at physiol...     

Benzo[h]quinoline based Macrocyclic Copper(II), Cobalt(II) Complexes: Synthesis,Characterization and Light induced DNA Cleavage Studies

A new ligand dibenzo[h]quinolineno[1,3,7,9] tetraazacyclododecine-7,15 (14H, 16H)-dibenzene (L) and its Co(II)/Cu(II) metal complexes of type [MLX₂] (Where (M = Co(II) (5), Cu(II) (6) and X = Cl) were synthesized and are well characterized by FT-IR, ¹H-NMR, FAB mass elemental analysis, and electronic spectral data. The role of the cobalt/copper metals in photo-induced DNA cleavage reactions was explored by designing complex molecules having macrocyclic structure. Finally, we have shown that photocleavage of plasmid DNA is more efficiently enhanced when this macrocyclic ligand is irradiated in the presence of copper(II) than that of cobalt metal.     

Spectroscopic, cyclic voltammetric and biological studies of transition metal complexes with mixed nitrogen-sulphur (NS) donor macrocyclic ligand derived from thiosemicarbazide

The complexation of new mixed thia-aza-oxa macrocycle viz., 2,12-dithio-5,9,14,18-tetraoxo-7,16-dithia-1,3,4,10,11,13-hexaazacyclooctadecane containing thiosemicarba-zone unit with a series of transition metals Co(II), Ni(II) and Cu(II) has been investigated, by different spectroscopic techniques. The structural features of the ligand have been studied by EI-mass, (1)H NMR and IR spectral techniques. Elemental analyses, magnetic moment susceptibility, molar conductance, IR, electronic, and EPR spectral studies characterized the complexes. Electronic absorption and IR spectra of the complexes indicate octahedral geometry for chloro, nitrato, thiocyanato or acetato complexes. The dimeric and neutral nature of the sulphato complexes are confirmed from magnetic susceptibility and low conductance values. Electronic spectra suggests square-planar geometry for all sulphato complexes. The redox behaviour was studied by cyclic voltammetry, show metal-centered reduction processes for all complexes. The complexes of copper show both oxidation and reduction process. The redox potentials depend on the conformation of central atom in the macrocyclic complexes. Newly synthesized macrocyclic ligand and its transition metal complexes show markedly growth inhibitory activity against pathogenic bacterias and plant pathogenic fungi under study. Most of the complexes have higher activity than that of the metal free ligand.     

Metal ion-directed synthesis of 16-membered tetraazamacrocyclic complexes and their physico-chemical studies

Complexes of Co(II), Ni(II), Cu(II) and Zn(II) containing macrocyclic tetradentate nitrogen donor (N4) ligand have been synthesized from the template condensation reaction between o-phthalaldehyde and o-phenylenediamine. The newly synthesized ligand and its complexes have been characterized on the basis of results of elemental analysis, molar conductance, magnetic susceptibility measurements, FT-IR, electronic, 1H FT NMR spectral data and Job's method. Their thermal behaviour has been studied by the thermogravimetric analysis. An octahedral geometry has been proposed for all of these complexes except the copper complexes, which show distorted octahedral geometry. The low conductivity data suggest their non-ionic nature. The biological activities of the metal complexes have also been studied against different bacteria.     

Glyphosate and ATP binding by mononuclear Zn(ii) complexes with non-symmetric ditopic polyamine ligands

Binding of Zn(ii) by the ditopic ligands L1py, L2py and L1para, composed of a cyclam unit linked to the linear polyamines 1,4,8,11-tetraazaundecane (L1py and L2para) and 1,4,7-triazaheptane (L2py) via a 2,6-dimethylpyridinyl (L1py and L2py) or a 1,4-dimethylbenzyl spacer (L2para), has been analyzed by means of potentiometric and (1)H and (13)C NMR measurements. All ligands form stable mononuclear Zn(ii) complexes in a wide pH range, featuring the metal ion bound to the macrocyclic unit. The open-chain polyamine unit can easily bind several protons in aqueous solution affording protonated metal complexes at neutral and acidic pH values. These complexes behave as bifunctional receptors for the anionic substrates N-(phosphonomethyl)glycine (glyphosate or PMG) and ATP. Potentiometric, (1)H and (31)P NMR measurements show that the Zn(ii) complex with L1py is the better receptor for both substrates, thanks to the simultaneous presence of a pyridine linker functionalized at its 2,6 positions and of a flexible linear tetraamine chain. In fact, these structural features allow a stronger interaction of PMG and ATP with both the protonated tetraamine moiety and the Zn(ii)-cyclam core.     

Coordination features of ditopic oxa-azamacrocycles toward Ni(II) and Co(II). Dioxygen uptake by their dinuclear Co(II) complexes

The coordination properties of the ditopic oxa-aza macrocycles L1-L3 toward Ni(II) and Co(II) have been investigated by means of potentiometric and UV-vis spectrophotometric measurements. L1-L3 contain two triamine and/or tetraamine chains separated by two dioxa chains and form both mono- and dinuclear complexes in aqueous solution. In the [ML]2+ complexes, the metal ion is coordinated by one of the two polyamine moieties, while the other does not participate in the coordination. In the dinuclear complexes each metal ion is coordinated, almost independently, to a single polyamine moiety. Under aerobic conditions the binuclear Co(II) complexes of the ligands L1-L3 are able to bind molecular oxygen, with a bridging coordination of O2 between the two metals.     

Kinetic and equilibrium studies on the polyazamacrocycle neotetren: metal-complex formation and DNA interaction

The macrocyclic polyamine 2,5,8,11,14-pentaaza[15]-[15](2,9)[1,10]phenanthrolinophane (neotetren) is studied in its ability to coordinate Cu(ii) even at very low pH values and to interact, as a metal complex, with DNA. The kinetics and equilibria for 1 : 1 and 2 : 1 metal-ligand complexes formation are studied by the stopped-flow method and UV spectrophotometry. Differently protonated complexes are formed, with rate constants much lower than that of water exchange at copper(II) and other Cu(II)/amine systems, this behaviour being ascribed to ring effects and intra-molecular hydrogen bonds. Concerning the DNA/copper(II)-neotetren complexes interaction, analysis of data suggests an intercalative mode of binding. The kinetic results for both DNA/CuL and DNA/Cu(2)L systems agree with the sequence D + S <-->D,S <-->DS where the metal complexes (D) react with the DNA sites (S) leading to fast formation of an externally bound form (D,S) which is converted into an intercalated complex (DS). A very slow process is also detected and ascribed to a conformational change in the polynucleotide secondary structure where the metal centre plays a crucial role. Chromatographic experiments demonstrate that both the investigated Cu(II)/L complexes are able to cleave DNA, but only in the presence of hydrogen peroxide.     

Mass, IR, electronic and EPR spectral studies on transition metal complexes with a new tetradentate 12-membered new macrocyclic ligand

Complexes of Cr(III), Co(II), Ni(II) and Cu(II) containing a novel macrocyclic tetradentate nitrogen donor (N4) ligand prepared via reaction of 2,3-hexanedione and ethylenediamine has been prepared and characterized. The newly synthesized ligand (L) and its complexes have been characterized on the basis of elemental analysis, molar conductance, magnetic moment susceptibility, EI-Mass, IR, Electronic and EPR spectral studies. The complexes are of high-spin type and four coordinated tetrahedral, five coordinated square pyramidal and six coordinated octahedral/tetragonal geometries. The ligand (L) and its soluble transition metal complexes have also been screened against different bacteria and plant pathogenic fungi in vitro.