四吡啶基卟啉质子化结构变化研究 Ⅱ.m - 甲基吡啶基的取代 基效应

卟啉衍生物对嵌入并堆积在DNA螺旋中具有高选择性,为考察m-甲基吡啶取代基对质子化卟啉结构的影响,在m-四吡啶基卟啉研究的基础上,用半经验的AM1MO方法,并进行合理的对称性限制,计算了m-四甲基吡啶卟啉(TmPyPH2^4+)及其质子化二酸(TmPyPH4^6+)的几种可能的构型,结果表明,由于m-甲基吡啶的影响,在质子化过程中结构和键电荷布居有明显变化;前沿分子轨道具有与四吡啶基情形相反的变化趋势,质子化二酸与溶液质子的快速交换作用也变得更困难了。     

四苯基卟啉质子化结构变化的理论研究

用半经验的ＡＭＩ ＭＯ方法,进行合理的对称性限制,计算了一类重要的卟啉衍生物──四苯基卟啉（ＴＰＰＨ_２）及其质子化二酸（ＴＰＰＨ_4~2 ）的构型,并通过结构分析,电荷布居分析和前线轨道分析,讨论了质子化过程中的构型变化以及这种变化对分子堆积可能带来的影响。     

四苯基卟啉质子化结构变化的理论研究（Ⅱ）－－五氟苯基及吡咯环上氟的取代基效应

卟啉的衍生物在DNA螺旋中的嵌入并堆积具有高选择性。为考察5，10，15，20－四（五氟苯基）卟啉（TF5PPH2）和2，3，7，8，12，13，17，18－八氟－5，10，15，20－四（五氟苯基）卟啉（F28TPPH2）中F取代基对质子化卟啉结构的影响，在四苯基卟啉研究的基础上，用半经验的AM1 MO方法，并进行合理的对称性限制，计算了TF5PPH2和F28TPPH2及其质子化二酸（TF5PHH4^2 ）和（F28TPPH4^2＋）的几种可能的构型。结果表明，由于F取代基的影响，质子化过程中的结构、键电荷布居和前线分子轨道均有明显的变化，二者的质子化二酸与溶液质子的快速交换作用也都变得更加困难。     

四苯基卟啉质子化结构变化的理论研究(Ⅱ)——五氟苯基及吡咯环上氟的取代基效应

卟啉的衍生物在DNA螺旋中的嵌入并堆积具有高选择性.为考察5,10,15,20-四(五氟苯基)卟啉(TF₅-PPH₂)和2,3,7,8,12,13,17,18-八氟-5,10,15,20-四(五氟苯基)卟啉(F₂₈TPPH₂)中F取代基对质子化卟啉结构的影响,在四苯基卟啉研究的基础上,用半经验的AM₁MO方法,并进行合理的对称性限制,计算了TF₅-PPH₂和F₂₈TPPH₂及其质子化二酸(TF₅-PPH₄²⁺)和(F₂₈TPPH₄²⁺)的几种可能的构型.结果表明,由于F取代基的影响,质子化过程中的结构、键电荷布居和前线分子轨道均有明显的变化,二者的质子化二酸与溶液质子的快速交换作用也都变得更加困难.     

三氟乙酸对无金属卟啉-茈酰亚胺分子阵列激发态衰变过程的影响

用紫外-可见吸收光谱和荧光光谱研究了CF3COOH浓度变化对CHCl3溶液中N-[P-5′-(m-10′，15′，20′-三苯基卟啉)基]-N′-正十二烷基-3，4:9，10-四羧基茈二酰亚胺分子阵列(TrPP-MDPTCDI)的光致激发态衰变机理的影响，发现无论激发无金属卟啉还是苝酰亚胺基元，分子阵列均表现出质子化无金属卟啉生色团的特征荧光发射.对电子结构的分析说明质子化使[H2^2 TrPP^ -MDPTCDI]成为各种激发态中相对稳定的物种，因此，未质子化前占主导的从卟啉到茈酰亚胺基元的光致电子转移衰变途径在质子化后受到有效抑制，激发卟啉生色团(λ=439nm)直接得到[H2^2 TrPP^ -MDPTCDI]，并以辐射衰变方式回到基态；激发苝酰亚胺生色团(λ=491nm)得到的[H2^2 TrPP-MDPTCDI^ ]通过电荷分离态迅速弛豫到[H2^2 TrPP^ -MDPTCDI]，并辐射荧光，同时伴随少量的从茈酰亚胺到质子化无金属卟啉生色团的能量转移.     

5,10,15,20-四(4′-氯乙酸乙酯基吡啶基)卟啉配合物的合成与表征

5,10,15,20-四(4-吡啶基)卟啉与氯乙酸乙酯反应得到5,10,15,20-四(4′-氯乙酸乙酯基吡啶基)卟啉(产率78．4％),后者与过量的醋酸锌发生络合反应得到新化合物5,10,15,20-四(4′-氯化乙酸乙酯基吡啶基)卟啉络锌(产率88．4％)。其结构经UV—vis,^1HNMR,IR和元素分析表征。     

镧系乙酰丙酮-5,10,15,20-四(4-吡啶基 )卟啉配合物

制备了乙酰丙酮-5,10,15,20-四(4-吡啶基)卟啉稀土配合物Ln(TPyP)acac[In:Dy,Ho,Yb,Lu;H~2TPyP:5,10,15,20-四(4-吡啶基)卟啉;Hacac:乙酰丙酮].配合物由一 个中心稀土离子,一个乙酰丙酮和一个四(4-吡啶基)卟啉组成,乙酰丙酮以氧双卤配位,卟啉以氮四卤配位,因此配合物有六配位的结构.     

新型卟啉吡啶季铵盐的合成与应用

采用微波技术合成了3种新型吡啶卟啉季铵盐:溴化5-[4-N-(对硝基)苄铵基吡啶基]-10,15,20-三(4-N-吡啶基)卟啉、氯化5-[4-N-(对甲氧基)苄铵基吡啶基]-10,15,20-三(4-N-吡啶基)卟啉和氯化5-[4-N-(对氯)苄铵基吡啶基]-10,15,20-三(4-N-吡啶基)卟啉.化合物的结构采用紫外可见光谱、红外光谱、核磁共振谱、质谱、元素分析测试技术得到确认.在分光光度法测定水中的痕量铜离子的显色反应中,配合物的表观摩尔吸光系数都在1×105L/(mol·cm)以上,是一种高灵敏度显色剂.该卟啉试剂具有显色和表面活性剂双重功能,应用于环境水样中铜的测定得到了满意的结果.     

三氟乙酸对无金属卟啉-苝酰亚胺分子阵列激发态衰变过程的影响

用紫外-可见吸收光谱和荧光光谱研究了CF₃COOH浓度变化对CHCl₃溶液中N-[p-5′-(m^-10′,15′,20′-三苯基卟啉)基]-N′-正十二烷基-3,4:9,10-四羧基二酰亚胺分子阵列(TrPP-MDPTCDI)的光致激发态衰变机理的影响,发现无论激发无金属卟啉还是酰亚胺基元,分子阵列均表现出质子化无金属卟啉生色团的特征荧光发射.对电子结构的分析说明质子化使[H₂²⁺TrPP^*-MDPTCDI]成为各种激发态中相对稳定的物种,因此,未质子化前占主导的从卟啉到酰亚胺基元的光致电子转移衰变途径在质子化后受到有效抑制,激发卟啉生色团(λ=439nm)直接得到[H₂²⁺TrPP-MDPTCDI^*],并以辐射衰变方式回到基态;激发酰亚胺生色团(λ=491nm)得到的[H₂²⁺TrPP^*-MDPTCDI]通过电荷分离态迅速弛豫到[H₂²⁺TrPP^*-MDPTCDI],并辐射荧光,同时伴随少量的从酰亚胺到质子化无金属卟啉生色团的能量转移.     

八乙基卟啉及其锌配合物的分子和晶体结构

测定了中位(meso)取代八乙基卟啉和无轴向配位卟啉锌(II)配合物的结构, 讨论了锌离子配位前后卟啉环的平面性, 并比较了有锌和无锌配位卟啉阴离子的几何构型。研究结果表明卟啉骨架的构型不仅决定于卟啉骨架中央孔穴的大小, 配位离子的尺寸和电子结构, 而且还决定于骨架上的取代基团。本文还分析了在卟啉骨架上取代硝基的几何构型以及它们在卟啉共轭效应中的作用。     

Theoretical studies on the structural change in the N-protonated tetraphenylporphyrin

The geometries of tetraphenylporphyrin which is a kind of important porphyrin derivatives, and its N-protonated diacid are calculated with AM1 MO method under symmetry restriction. The configurational changes and their effects on molecular aggregation are discussed by means of structure analysis, charge population analysis and frontier orbital analysis.     

单、 双及双混氮杂卟啉的结构和电子吸收光谱

利用密度泛函和含时密度泛函理论对卟啉(FBP)、 单氮杂卟啉(N/Neo-CPs)、 双氮杂卟啉(DNCPs)及双混氮杂卟啉(Neo-C-NCPs)的结构与电子吸收光谱进行了研究. 结果表明, 由于N/C位置改变, 分子对称性和轨道组成发生改变, 氮杂卟啉中2-NCP-2H, 2,18-DNCP-2H 和1,17-Neo-C-NCP的各前线和近前线轨道能级发生较大变化, 光谱峰红移较显著; 电子-空穴分布图表明3类氮杂卟啉电子跃迁途径更丰富. 进一步探讨了水、 氯仿和苯3种溶剂对4类卟啉分子的影响. 结果表明, 随着溶剂极性减小, FBP, N-/Neo-CPs, DNCPs和Neo-C-NCPs的Q带吸收峰红移越明显, 吸收略有增强.     

卟啉内氢迁移反应氟取代基效应的理论研究

The structures and energies of reactant, product, intermediate, transition and second order saddlepoint in the transfer reaction of inner hydrogen atoms in porphine(PH2), m-tetra-fluorine porphyrin(m-TFPH2), β-octa-fluorine-porphyrin (β-OFPH2) and m-tetra-fluorine, β-octa-fluorine-porphyrin(12FPH2) were calculated by using B3LYP/6-31G** method under certain symmetry restriction. In the transfer reaction of inner hydrogen atoms in all various matters, the comparison of structures and the energies shows that the probabilities of asynchronous mechanism are larger than that of synchronous mechanism via a second-order saddle-point, and substitutents to porphyrin in hydrogen migration have no influence on mechanism choice. But the substitutents can affect speed differences between the synchronous mechanisms and the asynchronous mechanisms. In addition, fluoro substitutents decrease speeds of positive and negative reactions in asynchronous mechanisms, which is in agreement with chemical intuition.     

Properties of polyethylene glycol supported tetraarylporphyrin in aqueous solution and its interaction with liposomal membranes

5,10,15,20-Tetrakis(4-hydroxyphenyl)porphyrin was functionalized by covalent attachment of poly(ethylene glycol) (PEG) chains of various molecular weights, 350, 2000, and 5000 Da. The properties of PEG-functionalized tetraarylporphyrins in aqueous solution and their interactions with liposomes have been studied. Electronic absorption spectroscopy, dynamic light scattering, atomic force microscopy, and fluorescence quenching were used to monitor aggregation of porphyrin chromophores and behavior of the attached PEG chains in the aqueous solution. The tendency for aggregation of porphyrin chromophores in aqueous solution and the efficiency of fluorescence quenching by KI decrease with increasing length of PEG chain linked to the porphyrin ring. The experimental results indicate that polymer clusters are present in aqueous solution of all pegylated porphyrins. The interactions between the pegylated porphyrins and phosphatidylcholine liposomes in the aqueous solution were studied using the fluorescence methods. The apparent binding constants of porphyrin chromophores to liposomes were determined. The degree of binding was found to be dependent on the molecular weight of the attached polymer.     

Peripherally fused porphyrins via the Scholl reaction: synthesis, self-assembly, and mesomorphism

Oxidative coupling of activated aryl groups attached to β-positions of the porphyrin ring provides convenient access to derivatives containing peripherally fused phenanthrene and benzo[g]chrysene units. Tetra(benzochryseno)porphyrin, reported here for the first time, contains a nonplanar, sterically locked π system and shows very intense electronic absorptions in the Q range of the electronic spectrum. Tetraphenanthroporphyrins show a tendency to aggregate in solution. In one case, a discrete dimer is formed, whose structure was investigated spectroscopically and theoretically. Derivatives bearing long alkyl chains are mesomorphic and exhibit columnar phases (tetraphenanthroporphyrins) and a monoclinic 3D phase (tetrabenzochrysenoporphyrin). The symmetry of column packing in the columnar phases is dependent on the number of alkyl chains per molecule. X-ray diffraction measurements show that, in spite of their nonplanarity, the aromatic cores in the mesophases are tightly stacked within the column. The corresponding stacking patterns were derived from the structure of the dimer, on the basis of geometrical analysis and molecular modeling.     

Raman and UV-visible absorption spectra of ion-paired aggregates of copper porphyrins

Raman and UV-visible absorption spectra of ion-paired aggregate constructed from two copper porphyrins, copper tetrakis(4-N-methylpyridyl)porphyrin (CuTMPyP) and copper tetrakis(4-sulfonatophenyl)pophyrin (CuTSPP), are reported in this paper. The absorption bands of the aggregate was found exhibiting obvious shift and broadening, which are attributed to the excitonic coupling between the two paired porphyrin rings. The excitonic coupling in the aggregates also induces evident alteration for Raman intensities compared with monomer spectrum. Aggregation results in only small shifts (2-3 cm(-1)) for Raman lines connecting with the vibrations of porphyrin rings, manifesting only slight structural change of porphyrin skeletons. On the other hand, evident downshift (5 cm(-1)) was observed for the Cm-pyridyl stretch mode (1254 cm(-1)) of CuTMPyP, suggesting weakening of the Cm-pyridyl bonds by aggregation. Raman depolarization ratios of the aggregates are different from those of the monomers, implying a lowering of effective symmetry due to the molecular packing in the aggregates.     

Switching the Photoluminescence and Electrochemiluminescence of Liposoluble Porphyrin in Aqueous Phase by Molecular Regulation

By a facile peripheral decoration of 5-(4-aminophenyl)-10,15,20-triphenylporphyrin (ATPP) with inherent aggregation-induced emission (AIE) active tetraphenylethene (TPE), a versatile AIEgenic porphyrin derivative (ATPP-TPE) was obtained, which greatly abolishes the detrimental π–π stacking and thus surmounts the notorious aggregation-caused quenching (ACQ) effect of ATPP in aqueous phase. The photoluminescence of ATPP-TPE is 4.5-fold stronger than ATPP at aggregation state. Moreover, an unequivocal aggregation induced electrochemiluminescence (AIECL) of ATPP-TPE was found to be seriously dependent on its aggregation property in aqueous solution with efficiency of 34 %, which is 6 times higher than pure ATPP. The versatility of this molecular structure modulation strategy along with the ACQ-to-AIE transformation in this work provides direction to guide for applying liposoluble porphyrins in aqueous phase by designs of synthetic porphyrin AIEgens.     

L-谷氨酸桥连的卟啉二联体配体及其铜配合物的合成、表征和性质研究

合成了未见报道的L-谷氨酸桥连的卟啉二联体配体及其铜的金属配合物, 并用红外光谱, 电子吸收光谱, 核磁氢谱, 元素分析和质谱等对化合物的结构加以确认, 研究了配体和金属配合物的CD, 拉曼光谱和荧光光谱的变化. 结果显示在配体中没有出现劈裂的Cotton效应, 而铜配合物中出现了劈裂的正负Cotton效应, 配体的荧光强度强于铜配合物的荧光强度, 在拉曼光谱中, 由于卟啉分子平面的对称性由D_2h变为D_4h群及其铜离子d轨道的电子效应, 在卟啉配体和铜配合物之间的拉曼光谱有很大差别.