【作者】 王璟琳；

【导师】 杨斌盛；

【作者基本信息】 山西大学 ， 无机化学， 2011， 博士

【摘要】 取代腙配体及配合物具有独特的结构特征和功能特性,在对映异构体选择性合成、不对称催化、多孔材料、磁性材料、非线性光学材料、探针技术以及DNA识别等领域有着潜在应用前景。因此,含取代腙的金属-有机配位化合物的设计与合成、结构及功能特性的研究与开发已经成为配位化学、生物无机化学、晶体工程学和材料科学发展的前沿领域之一。本论文合成了一系列取代腙化合物,包括毗啶酰腙、酚酰腙、半卡巴腙、硫酰腙、磺酰腙、双腙以及相应的配合物,其合成方法、表征手段、晶体分析等内容贯穿于全文,但各章关注的重点有所不同。第二章侧重于配体和配合物的发光性质研究；第三章探索了配合物与DNA的相互作用以及切割DNA的活性；第四章注重于配体识别锌离子的光谱分析以及铜配合物的量化计算分析；第五章主要考查了磺酰腙配合物的结构特性、分析了镍配合物的量化计算结果；第六章关注的焦点则是主体分子识别氟离子的比色分析研究。总之,本文基于化合物的合成与表征、晶体结构分析、量化计算及物质性质等四个方面展开研究工作。0.1化合物的合成与表征本文主要采用常规的溶液合成方法。以酰腙配体为例,选择肼为原料并和三氯乙酰基化合物发生取代反应生成酰肼,其中的胺基(-NH2)再和醛或酮反应形成非中心对称的取代腙配体。在一定的实验条件下,通过选择适当的端基和／或桥基取代腙配体以及金属盐,成功地合成出一系列单核、双核和多核配合物并对其进行了元素分析、核磁、红外、紫外可见、荧光及单晶X-射线衍射实验等表征。0.2晶体结构分析本文合成的36个取代腙化合物中,其中30个单晶为首次报道,晶体的共同特征是结构的多样性和稳定性。取代腙配体的主要特点是：(i)包含了可以自由旋转的N-N和C-C单键,可以采取顺式或反式构型同中心离子配位,对于不同的中心离子,取代腙既可以作为多齿端基配体,也可作为桥基配体。(ii)当酰腙基两端连接芳基后常常形成共平面的共轭体系,有利于π堆积；若取代基中含有强的吸电子基或氮杂原子,使芳环平面的电子密度降低,更利于π堆积。取代腙金属配合物的特点如下：(i)新颖的结构和成键方式。如四配位的平面四边形钴配合物、二维多聚的钾配合物等具有新颖的结构。而独特的成键方式体现在磺酰基氧原子同中心金属Ni2+形成了强的配位键,以及镉的三唑类一维多聚配合物中形成的,u3-Cl桥键。(ⅱ)非典型M-Cl…H-D氢键。在多个金属配合物中,形成了M-Cl…H-D(D=C,N,O)氢键,表明M-Cl是良好的氢键接受体。(ⅲ)新型的π堆积模式。本文合成的化合物普遍存在π堆积作用,源于配体中包含有苯环或氮杂环,其中比较新颖的是P4AE-OFF+OFF作用链、P4AE-EF作用链及其形成的面、分子间的p…π弱相互作用等。(ⅳ)形成二聚配合物的倾向。由于配体的非对称性,导致配合物具有手性且手性中心位于金属原子上(Chiral-at-Metal)。但常常形成对映异构体来提高其对称性从而增强稳定性。对映异构体是通过分子间的弱相互作用来进行识别的,弱相互作用的类型大多有π堆积作用和氢键以及不多见的d…π相互作用,其中d…π相互作用主要存在于铜的配合物中,这些作用是对映异构体识别的主要驱动力。但是,汞配合物(4)则不然,其弱相互作用类型为Hg…Hg、Hg…Cl和Cl…Cl。0.3基于量化计算的理论分析利用B3LYP/60-31++G**方法,对镍配合物(23)的二聚体结构单元进行单点能计算,结果表明,P4AE堆积中存在着OFF和EF的协同效应,除配位键外,形成晶体的主要驱动力应归于这种P4AE堆积作用。与芳基非共面的氮原子可能参与形成共轭体系,从几何学和对称性角度分析了氮原子参与的可能性。在铜配合物(19)(C=0基氧原子配位)和(21)(C=S基硫原子配位)体系中,dxy轨道的能量差异较大,可能的原因是配合物(21)中S原子不但提供电子对和Cu2+配位,也提供dxy空轨道接受Cu2+反馈的d电子而形成d-d反馈π键。0.4化合物性质研究化合物的性质研究主要包括以下四方面：(i)固态荧光性质研究。对化合物1-5固态荧光光谱研究表明,激发波长400 nm,对应的发射峰分别在490、505、555、550、535 nm。荧光强度次序为2>3>4>5≈H1,荧光增强效应是由于配体和金属离子结合后有效地增强了配合物的刚性,以及减少了无辐射衰减过程中的能量损失。在配合物3、4中,由于重原子效应明显地导致其荧光猝灭。和溶液荧光相比,固态荧光发射峰位发生显著红移,可能是由于固态中存在着强的π…π相互作用能有效地降低HOMO与LUMO之间的能隙。对几个萘取代腙化合物的固态荧光光谱研究表明,固定激发波长450 nm,化合物H229、H31、H235的发射波长分别在545、547、556nm,体现出良好的发光性能。而H13则没有荧光,可能是由于该化合物中有强的吸电子基团(-NO2)导致其荧光猝灭。(ⅱ)双核锰配合物(9)的磁性研究。在外加磁场为1KOe,温度测量范围为2～300K,磁化率(χM)和有效磁矩(μeff)随温度的变化曲线表明,在Mn3+中心之间存在反铁磁相互作用。(ⅲ)配合物与DNA作用研究。化合物6-10、12与CT-DNA及pBR322 DNA作用研究表明,配合物7(铜配合物)有较高的反应活性。可能的原因是该配合物为四配位的平面构型,有利于和DNA作用。配合物7与CT-DNA作用表现为准一级反应,表观速率常数为3.62±0.17 h-1。用凝胶电泳法研究了系列化合物对pBR322 DNA的切割作用,实验表明,在近生理条件下配合物7切割pBR322 DNA的表观速率常数为1.41±0.06 h-1,在配合物7-pBR322DNA体系引入自由基清除剂和氧化还原剂的电泳实验揭示其机理为水解切割。(ⅳ)离子识别研究。主体分子H216对锌离子有较好识别作用。在近生理条件下的条件稳定常数为1gK=12.89±0.76。Zn2+-H216体系紫外差光谱研究表明,△A353nm-△A311nn值与锌离子的量有着明显的响应关系,可以通过该值的变化来识别或检测锌离子。主体分子H230在DMSO/H2O(4:1)体系中能有效地识别氟离子,用“裸眼”可直接观察其颜色变化。氟离子在8.5×10-7～4.4x10-5M(R2=0.9946)范围内有较好的线性关系,检出限为5.8×10-7M。更多还原

【Abstract】 The substituted hydrazones and their metal complexes have developed rapidly in recent years because of their fascinating structural and potential applications in the fields of enantioselective synthesis, asymmetric catalysis, porous materials, nonlinear optical materials, magnetic materials, probe technique, DNA recognition and so on. Therefore, the rational design, synthesis, and characterization of novel substituted hydrazones and their metal complexes are of fundamental importance for the further developments of supramolecular chemistry and coordination chemistry.In this thesis, a series of new substituted hydrazones and their metal complexes were synthesized. One of the important substituted hydrazones is the acyl-/aroyl-hydrazone compound. These compounds not only display interesting structures, which are assembled by such as coordination bonding, hydrogen bonding, aromaticπ…πstacking and so on, but also exhibit different coordination modes of different aromatic hydrazone ligands. In this paper, we reported the crystal structures, various spectroscopic studies, magnetism, anion or cation recognition, and DNA binding and cleavage activities of the new substituted hydrazone complexes.0.1 Synthesis and characterization of substituted hydrazone compounds.Compared with different synthetic approaches of the compounds, the general solution approach was chosen. The acyl-/aroyl-hydrazone can be seen as the result of the reaction of an aldehyde or a ketone with an acyl-/aroyl-hydrazine that has a free -NH2 group. In suitable experimental conditions using appropriate bridging ligands, we have been successful in synthesizing a series of mono-, di- and polynuclear transition metal complexes with substituted hydrazone ligands. These complexes were characterized by X-ray crystallography, IR, UV-Vis,1H-NMR spectroscopy, and elemental analyses. 0.2 Crystal and molecular structure.As a terminal or bridged-ligand, the hydrazones ligands have the following features:(ⅰ) Flexibility. It contains N-N and C-C single bonds, which can freely rotate according to the demand of coordination, making the hydrazone ligand as a potential bidentate, tridentate or polydentate chelating ligand. (ⅱ) The aryl group and acyl-hydrazone (R2C=N-N-CO-R) form a co-planar delocalized molecule. It may construct new structures viaπstacking interactions. It contains aromatic nitrogen heterocycles, in principle, should be well suited forπ…πinteractions because of lowπ-electron density resulting from nitrogen heteroatoms, which serve as electron acceptors within the ring.The hydrazone complexes have the following features:(ⅰ) Novel structures and bonding modes. The structural studies indicate that tridentate acyl-hydrazone ligand has commonly been coordinated to metals at a 1:1 metal/ligand ratio, which allows the formation of molecular polygons, chains or layer and exhibits a rich degree of superstructural diversity. However, the substituted hydrazone ligand also occasionally exhibits as bi-dentated or penta-dentated ligand, for example in complex 3 and 5. (ⅱ) Non-classical M-Cl…H-D hydrogen bonding. The results indicated that M-Cl moieties were good anisotropic hydrogen-bond acceptors; (ⅲ) Novelπstacking modes. In this paper we surveyed and analyzed multiple edge-to-face (EF) and offset-face-to-face (OFF) interactions forms in crystal packing. The parallel fourfold aryl embrace (P4AE, comprised of one OFF and two EF) occurs for compounds 20,23,25,27,29; (iv) Trend to form dimers. Among the complexes, the dimers were formed by theπ…π, d…π, M…M, M…Cl, Cl…Cl weak interactions and hydrogen bonding. The complexes contain the asymmetrical N-heterocyclic ligands with a tendency to form chiral complexes (enantiomeric forms), in which the only asymmetric center is the metal itself (chiral-at-metal). The enantiomorph was formed by these weak interactions. 0.3 The theoretical analysis based on calculating results of quantum chemistry.The geometries of the 19,23 were definited by crystal information files. The geometries of the 21 were optimized using the B3LYP/6-31++G** basis set. These geometries were used to perform single point calculations using the Gaussian03 program package. The calculating results show that complexes 23 exist synergistic effects of EF-OFF interactions, and the non-coplanar N atom with aromatic ring possibly participate in delocalizingπsystem. In the complexes 19,21, the eigenvalue of the dxy orbit has large difference, it is reasonable to conclude that not only the S atom of ligand coordinate to Cu2+, but also the unoccupied d orbit of the S atom can accept the d electron from Cu2+, to form freeback d-dπbonding in complex 21.0.4 Studies on the properties of the compounds.(ⅰ) Solid-state fluorescence spectral properties. Compared with the solution fluorescence spectra, the most drastic red-shift is observed in the solid-state spectra, which may be assigned to intra-ligand (π→π*) fluorescent emission stemming fromπ…πstacking and hydrogen bonding interactions. These interactions play an important role in decreasing the HOMO-LUMO gaps. (ⅱ) The experimental data of the variable-temperature (2～300 K) magnetic susceptibilities display an antiferromagnetic exchange between the bridged Mn3+ ion in complex 9. (ⅲ) Interactions of DNA and complexes. Interactions of DNA and the complexes 6-10,12 indicated that complex 7 has higher activity. The UV-Vis titrations of 7 with CT-DNA were done in Tris-HCl buffer medium, and showed significant hypochromism. The gel electrophoresis shows that complex 7 is able to perform an efficient cleavage of pBR322 DNA. When pBR322 DNA was incubated with the 7 in the presence of hydroxyl radical scavengers or reductant-oxidant, inhibition of the DNA cleavage was not observed. These observations suggested that 7-mediated cleavage reaction occurs via a hydrolytic path. (ⅳ) Studies of the ions recognization. UV-Vis spectral studies show that the host molecule H216 provides strong binding of Zn2+ in a 1:1 ratio in solution. The conditional binding constant of the complex is 1gKZn-16=12.89±0.76 in 0.05 M Tris-HCl buffer at pH 7.4. The change in theΔA353 nm-ΔA311 nm of H216 is more pronounced in the presence of Zn2+ than other metal ions. Therefore, the analysis ofΔA353 nm-ΔA311 nm, with respect to difference spectral changes at 353 and 311 nm, is possible to determine Zn2+. The H216 exhibits an enhanced fluorescence effect by the addition of Zn2+, and affords an excellent selectivity for Zn2+ under physiological conditions. In DMSO/H2O (4:1) system, the adding of F- to the solution of the host molecule H230 caused dramatic changes in color which were clearly visible to the naked eye. However, no significant changes of color were observed when H230 was exposed to Cl-, Br-, I-, OAc-, and H2PO4- respectively. The absorption spectral studies indicated that a good linear relationship between the absorbance and the F- ion concentration could be obtained from 8.5×10-/ to 4.4×10-5 M (R2=0.9946). The detection limit was measured to be 5.8×10-7 M.更多还原