【作者】 洪涌；

【导师】 陈立泉； 黄可龙；

【作者基本信息】 中南大学 ， 应用化学， 2010， 博士

【摘要】 Salphen是含有[N,N’-bis(salicylidene)1,2-diaminobenzene,N,N’-双水杨醛缩-1,2-苯二胺]骨架结构的双Schiff碱,其是一四齿配体,具有类卟啉结构,由于其独特的结构,近年来引起人们的极大兴趣。本论文用冰浴法合成了一系列Salphen型双Schiff碱及其它双Schiff碱化合物,其中四个为新化合物,并对其进行了IR,1HNMR波谱表征,测定了化合物在溶液中以及固态时的紫外吸收光谱和荧光光谱,探讨了双Schiff碱苯环上不同的取代基类对光谱影响。实验结果表明,水杨醛上的邻羟基是双Schiff碱具有荧光性质必要条件；极性溶剂中,苯甲醛邻位和对位上-OH的存在均可引起双Schiff碱结构的变化；与固体相比,双Schiff碱在溶液中的荧光强度较弱,且在317nm和400nm光激发下均有荧光发射峰。培养了一种新化合物5,5’-二氟-SalphenH2(C20H14F2N202)的单晶,并用x射线单晶衍射技术对其结构进行解析,在此基础上进一步制备5,5’-二氟-S alphenZn(II)配合物(C20H12F2N202Zn),通过核磁共振谱,红外光谱,元素分析等波谱手段对此化合物进行结构表征和分析,并且探讨了其固态和溶液状态的荧光性能。结果表明：5,5’-二氟-Salphen(C20H14F2N2O2)Schiff碱晶体属于单斜晶系,P2(1)/c空间群,晶胞参数a=6.0938(8),b=16.347(2),c=94.474(2),V=1651.9(4),Z=4,Dc=1.417,V=1651.95(4)A3,Z=4,Dc=1.417g/cm-3,μ(MoKa)=0.11mm,F(000)=728,T=293 K,R=0.032。配合物以Zn2+为中心原子,与Schiff碱上的N原子和O原子形成配位数为4的配合物。应用计算化学理论来说明双-4-羟基-苯甲醛缩-1,2-苯二胺(化合物e)分子结构、电子跃迁和光化学性质及分子内电荷转移现象。所有的计算都在Gaussian 03软件中完成的,运用密度泛函理论中的杂化密度泛函方法RB3LYP优化得到基态的分子后,用RB3LYP方法得到基态能量,用RCIS-FC方法得到激发态能量,原子的基组为6-311+G(d)。通过RCIS-FC方法,基组6-311+G(d)计算出来双-4-羟基-苯甲醛缩-1,2-苯二胺(化合物e)的激发态4(222.71nm)和激发态1(267.72nm)与化合物e在乙醇溶液中的紫外吸收峰实验值分别为225nm,285nm很接近,计算数据和实验数据得到了较好的吻合。研究表明计算所得的化合物e基态和激发态前线轨道(HOMO)及分子的静电势能直观地说明具有D-π-A结构Schiff碱的光激发下分子内电荷转移现象。从双Schiff碱出发,合成了一种新型水合双-[2-(2-氯-4-氟苯基)-1H-苯并咪唑],对其单晶进行了x射线单晶衍射,并对反应机理进行研究。结果表明,其晶体属于三斜晶系,P1空间群,晶胞参数a=7.592(2),b=7.595(2),c=11.886(3)A,V=574(3)A3,Mr=352.33,Dc=1.478g/cm3,(MoKα)=0.33 mm-1,F(000)=262,Z=1,R=0.090 and wR=0.209。这种化合物的晶体结构由两个苯并咪唑单分子组成,通过一个水分子连接,与苯并咪唑衍生物的配合物结构相似。发现只有当邻位不存在-OH时,Schiff碱才能进一步关环得到苯并咪唑衍生物。对所合成的晶体结构进行了详细的分析,在其超分子结构内存在分子内或分子间氢键,其中5,5’-二氟-SalphenH2存在π-π堆积的弱分子间相互作用。更多还原

【Abstract】 Salphen[Salophen,N,N-bis(salicylidene) 1,2-diaminobenzene]-type Schiff bases are bis-Schiff bases with tetradentate coordination and their structures are similar to the porphyrin. Salphen-type Schiff bases have attracted considerable attention of chemists in recent years owing to the special structure.In this thesis, A series of Salphen-type Schiff bases and other bis-Schiiff bases were synthesized by reacting substituted aromatic aldehydes and primary amines under ice bath, four of which were first reported. The chemical structures of these compounds were confirmed by means of IR and 1HNMR.UV absorption and fluorescence spectrum of the compouds were detected in solution and in solid state, and the relationship between the molecule structure and the spectrum was also studied. The results show that an OH group in an ortho-position in the salicylaldehyde is the necessary condition of schiff base compounds which possess strong fluorescence properties. In the polar solvent, the exist of an OH group in an ortho or para position can cause the change of structure of bis-schiff bases; Compared with the solid state, the schiff base’s fluorescence is weaker when in the solvent and exhibits emission in the 317nm and 400nm.In this study,5,5’-difluoro—SalphenH2 was synthesized by reactions of the o-phenyldiamine with 5-F-salicylaldehyde under ice bath. Its structure has been investigated by X-ray single crystal diffraction. It reveals that the compound belongs to monoclinic P2(1)/c space group, a =6.0938(8), b=16.347(2), c=94.474(2), V=1651.9(4), Z=4, Dc =1.417 andμ=0.11. The Zn (Ⅱ) complex has also been prepared here and characterized by the analytical and spectroscopic methods. According to the characterization data, the structure of the complex was interpreted and its fluorescence properties were also investigated.Computational chemistry theory is used to explain the bis-Schiff base molecular structure, electronic transition, photochemical properties and intramolecular charge transfer phenomenon. All calculations in this work are carried out using the Gaussian 03 package. Geometries were optimized at the RB3LYP/6-311+G (d.) level. The ground state energy was obtained with RB3LYP method, excited state energy was obtained with RCIS-FC method. The atomic basis set is 6-311+G (d.).Using frontier orbital (HOMO) of ground state and excited states and the moleculal electrostatic potential explain the phenomenon of intramolecular charge transfer of compound e with D-π-A structure.The excited state energy of bis-4-hydroxy-benzaldehyde 1,2-phenyl-enediamine (compound e) obtained with RCIS-FC method is 222.71nm (excited state 4) and 285nm(excited state 1) is very close to the result observed in the UV absorption peak of the experimental values of compound e (ethanol solution),which is 225nm,285nm, respectively. The calculation results are in good agreement with the experimental data.Bis-[2-(2-chloro-4-fluorophenyl)-1H-Benzimidazole]-hydrate has been synthesized from bis-Schiff base. The results determined by XRD reveals that the complex crystallizes in Triclinic, space group P1, with a = 7.592(2), b=7.595(2), c=11.886 (3) A, K=574(3) A3, Mr=352.33, Dc = 1.478g/cm3,μ(MoKa)= 0.33 mm-1, F(000)= 262, Z=1, the final R= 0.090 and wR=0.209. The crystal structure is formed with two benzimidazole molecules, which are linked by a water molecule as center, similar to the complex of benzimidazole. The reaction mechanism was also discussed by changing reaction conditions. It is demonstrated that benzimidazole can only be formed from Schiff base effectively when o-hydroxyl group does not exist in benzaldehyde.Detailed crystallographic analyses of the compounds were carried out. The intramolecular or intermolecular hydrogen bonds are existed in the supermolecular structures,π-πinteraction is existed in the crystal structure of 5,5’-difluoro-SalphenH2.更多还原