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Synthesis, characterization, electrochemistry, and spectroelectrochemistry of group 8 metalloporphyrin complexes.

机译：第8族金属卟啉配合物的合成，表征，电化学和光谱电化学。

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This dissertation describes the investigations of nitric oxide (NO) and possible NO donors with group 8 metalloporphyrins.;Chapter one is written in a manner so that the general public could read and understand the work that has been done for this dissertation.;Chapter two describes the redox properties of (por)Ru(CO)(L) (por = tetraphenylporphyrin (TPP), octaethylporphyrin (OEP); L = pyridine and 1-MeIm) complexes. A new technique utilizing chronoabsorptometry and chronoamperometry for investigating short lived "intermediate" species that are formed on the cyclic voltammetric (CV) time scale is used in order to probe the visible region of the electronic spectra of the redox-generated species. This new technique has provided results that are similar to previous reports but now it can be done with shorter scan times (which can minimize decomposition) and less manual manipulation of the data such as subtractions and smoothing. As a result, more detail in the spectrum is obtained by using this new chronoabsorptometry-chronoamperometry technique. Also, we were able to provide the first difference IR spectra for the products generated from their second oxidations.;Chapter three describes the synthesis of new 6-coordinate ruthenium porphyrin nitrosyl aryloxide ((por)Ru(NO)(OR)) complexes (por = OEP, TPP and R = -C 6H5 (Ph), -C6H4-2-NHC(=O)CF3 (1HOL), -C6H3-2,6-(NHC(=O)CF 3)2 (2HOL), and -NHC(=O)-C 6H4-o-OH (SalHate) that show varying amounts (0,1,2) of internal H-bonding. These complexes appear to be good structural models of the heme active site of catalase, which has a tyrosinate ligand coordinated to the iron and internal H-bonds in the active site. They were synthesized by the reaction of the (por)Ru(NO)(O-i-C 5H11) or (por)Ru(NO)(OEt) precursor with the appropriate alcohol. The complexes were characterized with the use of 1H NMR, IR, mass spectrometry, cyclic voltammetry, IR spectroelectrochemistry, and UV-vis spectroelectrochemistry. The nuNO of 1821 - 1842 cm-1 for these complexes is higher than those of known ruthenium porphyrin nitrosyl alkoxide complexes with nuNO ranges of 1790 - 1810 cm-1, most likely due to the conjugation of the phenyl ring found in the aryloxide complexes, which can delocalize electron density. This influences the metal to nitrosyl ligand back-donating ability affecting the N-O bond strength. We also notice a direct correlation of nuNO to the number of internal H-bonds in the complexes. The structural information gathered from these new (por)Ru(NO)(OR) aryloxide complexes shows similar characteristics to known structures of the (por)Ru(NO)(OR) alkoxide complexes. The only major difference lies in the ∠RuOR bond angles. The (OEP)Ru(NO)(OR) (R = 1HOL and 2HOL) complexes have ∠RuOR bond angles of 122.26(15) and 124.5(3)º respectively, which are smaller than the reported values of 133.853--143.8(5)º. The first oxidation potentials also appear to be increasing with increasing number of internal H-bonds. The cyclic voltammetry for these complexes displays an ECE mechanism. The complexes appear to decompose during the first oxidations, while the second oxidations appear to be taking place on the porphyrin rings due to the observation of the porphyrin pi-cation radical peaks in the difference IR spectra.;Chapter 4 describes the synthesis and characterization of 5-coordinate iron porphyrin complexes, where the 5th coordination site is occupied by a hydroxamate, acetate, or aryloxide ligand. The (por)Fe(hydroxamate) complexes (POR = (T(p-OMe)PP) and OEP, R = salicylhydroxamate) showed very unique coordination. The hydroxamate moiety of the ligand, which is typically thought of as a bidentate ligand with respect to iron coordination, was not involved in binding to the metal center. Instead, salicylhydroxamic acid coordinates to the iron center via the phenyl hydroxyl moiety, as determined with X-ray crystallography. The electrochemical investigations of the (por)Fe(acetate) and (por)Fe(aryloxide) complexes each showed two reversible features during oxidation within the solvent limits of the experiments performed which was consistent with reports of known (por)Fe(OR) complexes. The electrochemical behavior of the (por)Fe(salicylhydroxamate) complexes provided more complicated cyclic voltammograms. This was most likely due to instability of the complexes upon oxidation. Infrared spectroelectrochemical investigations of the (por)Fe(salicylhydroxamate) complexes provided difference spectra which suggest the formation of a cationic [(por)Fe(NO)]+ complex upon oxidation. This was due to the new bands in the IR spectrum at 1839 cm-1 and 1855 cm -1 for the (T(p-OMe)PP)Fe(salicylhydroxamate) and (OEP)Fe(salicylhydroxamate) complexes respectively. This is the first report of a coordinated hydroxamate donating NO. The reactivity of the (por)Fe(OR) complexes with nitrite and NO, which suggest the formation of new (por)Fe(NO X)y complexes, are also discussed in this chapter.
机译：本论文描述了使用第8组金属卟啉对一氧化氮（NO）和可能的NO供体的研究。第一章的编写方式使公众可以阅读和理解本论文所做的工作。第二章描述了（por）Ru（CO）（L）（por =四苯基卟啉（TPP），八乙基卟啉（OEP）; L =吡啶和1-MeIm）配合物的氧化还原性质。为了探测氧化还原产生的物种的电子光谱的可见区域，使用了一种利用计时吸收法和计时电流法研究在循环伏安（CV）时间尺度上形成的短寿命“中间”物质的新技术。这项新技术提供的结果与以前的报告相似，但是现在可以用更短的扫描时间（可以最大程度地减少分解）并且减少对数据的手动处理（例如减法和平滑化）来完成。结果，通过使用这种新的计时吸收法-计时电流法技术可以获得频谱中的更多细节。同样，我们能够为由其第二次氧化生成的产物提供第一差红外光谱。;第三章描述了新的六配位钌卟啉亚硝酰基芳基氧化物（（por）Ru（NO）（OR））配合物的合成（ por = OEP，TPP和R = -C 6H5（Ph），-C6H4-2-NHC（= O）CF3（1HOL），-C6H3-2,6-（NHC（= O）CF 3）2（2HOL）和-NHC（= O）-C 6H4-o-OH（SalHate）表现出不同数量的（0,1,2）内部H键，这些配合物似乎是过氧化氢酶血红素活性位点的良好结构模型，具有在活性位点与铁和内部氢键配位的酪氨酸盐配体，是通过（por）Ru（NO）（OiC 5H11）或（por）Ru（NO）（OEt）反应合成的用1H NMR，IR，质谱，循环伏安法，IR光谱电化学和UV-vis光谱电化学对复合物进行表征，这些复合物的nuNO在1821-1842 cm-1处更高。 rutheniu的m卟啉亚硝酰基醇盐配合物的nuNO范围为1790-1810 cm-1，最有可能是由于在芳氧基配合物中发现的苯环的结合，这可以使电子密度离域。这影响了金属对亚硝酰基配体的返还能力，从而影响了N-O键的强度。我们还注意到nuNO与复合物中内部H键的数量直接相关。从这些新的（Ru）Ru（NO）（OR）芳氧化物配合物收集的结构信息显示出与（Ru）Ru（NO）（OR）烷氧化物配合物的已知结构相似的特征。唯一的主要区别在于∠RuOR键角。 （OEP）Ru（NO）（OR）（R = 1HOL和2HOL）配合物的∠RuOR键角分别为122.26（15）和124.5（3）º，小于报告的值133.853--143.8（ 5）º。随着内部氢键数目的增加，第一氧化电位也似乎增加。这些络合物的循环伏安法显示了ECE机制。配合物似乎在第一次氧化过程中分解，而第二次氧化似乎是在卟啉环上发生的，这是由于在不同的红外光谱中观察到了卟啉π-阳离子自由基的峰。第四章描述了卟啉的合成和表征。 5-配位铁卟啉配合物，其中第5个配位位被异羟肟酸酯，乙酸酯或芳氧基配体占据。 （por）Fe（异羟肟酸酯）络合物（POR =（T（p-OMe）PP）和OEP，R =水杨酸异羟肟酸酯）显示出非常独特的配位作用。配体的异羟肟酸酯部分，通常被认为是关于铁配位的二齿配体，不参与与金属中心的结合。而是，水杨基异羟肟酸经X-射线晶体学测定通过苯基羟基部分配位至铁中心。 （por）Fe（乙酸盐）和（por）Fe（芳基氧化物）配合物的电化学研究显示，在进行的实验的溶剂极限内，氧化过程中有两个可逆的特征，这与已知的（por）Fe（OR）的报告一致复合体。 （por）Fe（水杨酸异羟肟酸酯）配合物的电化学行为提供了更复杂的循环伏安图。这很可能是由于复合物在氧化时的不稳定性。 （por）Fe（水杨基异羟肟酸酯）配合物的红外光谱电化学研究提供了差异光谱，其表明氧化后形成了阳离子[（por）Fe（NO）] +配合物。这是由于（T（p-OMe）PP）Fe（水杨基异羟肟酸酯）和（OEP）Fe（水杨基异羟肟酸酯）络合物分别在1839 cm-1和1855 cm -1的红外光谱中出现的。这是协调性异羟肟酸酯捐赠NO的第一份报告。 （por）Fe（OR）配合物与亚硝酸盐和NO的反应性表明新的（por）Fe（NO X）y配合物的形成在本章中也进行了讨论。

著录项

  • 作者

    Warhausen, Adam.;

  • 作者单位

    The University of Oklahoma.;

  • 授予单位 The University of Oklahoma.;
  • 学科 Chemistry General.;Chemistry Inorganic.
  • 学位 Ph.D.
  • 年度 2012
  • 页码 151 p.
  • 总页数 151
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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