RAMAN STUDIES OF PORPHYRINS AND RELATED MACROCYCLES

卟啉和相关大环的拉曼研究

• 批准号: 3289808
• 负责人: DAVID F. BOCIAN
• 金额: $ 19.16万
• 依托单位: UNIVERSITY OF CALIFORNIA RIVERSIDE
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-07-01 至 1994-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3289808
• 关键词: Raman spectrometry; chemical structure function; chemical synthesis; electron transport; electronic spectra; infrared spectrometry; intermolecular interaction; metal complex; metalloporphyrins; optical polarization; oxidation reduction reaction; porphyrin structure; porphyrins; tetrapyrroles

The general objectives of the proposed research are to characterize the structural, electronic and magnetic properties of porphyrins, hydroporphyrins and structurally related bio-macrocycles. A variety of methodologies will be used including Resonance Raman (RR), infrared (IR), absorption and electron paramagnetic resonance (EPR) spectroscopies, normal coordinate analysis, and semiempirical quantum force field calculations. The procedures, aims and rationales for the studies are as follows: (1) The RR and IR spectra of a variety of prototypical chlorins, bacteriochlorins and isobacteriochlorins will be characterized in detail. The vibrational data will be analyzed via both conventional normal coordinate and semiempirical quantum force field methods. The semiempirical calculations will be refined and extended to protein prosthetic groups, such as siroheme, heme d1 and cofactor F430, which are not amenable to conventional vibrational analysis procedures because large numbers of isotopomers are not available. The aim of these studies is to provide a foundation for the interpretation of the vibrational data of reduced-pyrrole macrocycles in general. These bench marks are needed (but not generally available) in order to extract structural information from the vibrational spectra of hydroporphyrins in proteins. (2) The RR and IR spectra of pi-cation and pi-anion radicals of various porphyrins and hydroporphyrins will be characterized. Normal coordinate calculations will be performed on these species by using both conventional and semiempirical quantum force field methods. Vibrational and EPR spectra of various metal-reduced hydroporphyrins, such as complexes of Fe(I) and Ni(I), will also be examined. The aim of these studies is to characterize the structural and electronic perturbations induced by the addition or removal of electrons. A quantitative assessment of the effects of oxidation/reduction is needed (but again not generally available) in order to extract structural information from the spectra of oxidized/reduced tetrapyrrolic intermediates in proteins. (3) The RR, IR, EPR and optical spectra of a series of neutral, oxidized and reduced porphyrin and hydroporphyrin dimers and trimers [structure Ln(ring)2, (ring)Ln(ring') and Ln2(ring)3] will be examined. The aim of these studies is to determine the influence of strong pipi interactions on the electronic properties of the complexes and provide a foundation for assessing how such electronic communication might mediate energy and/or electron transfer between tetrapyrrolic prosthethic groups in proteins.

拟议研究的总体目标是表征 卟啉的结构、电子和磁性， 氢化卟啉和结构相关的生物大环化合物。 一 将使用多种方法，包括共振拉曼 (RR)、红外（IR）、吸收和电子顺磁共振 (EPR)光谱学、标准坐标分析和半经验分析 量子力场计算 程序、目标和 研究的基本原理如下： (1)各种典型二氢卟酚的RR和IR光谱， 菌绿素和异菌绿素的特征在于， 详细 振动数据将通过以下两种方法进行分析： 常规简正坐标与半经验量子力 现场方法 半经验计算将被细化， 扩展到蛋白质辅基，如siroheme、heme d1 和辅因子F430，它们不服从常规的 振动分析程序，因为大量的 没有同位素异构体。 这些研究的目的是 为解释振动数据提供了基础 还原吡咯大环化合物。 这些基准点是 需要（但通常不可用），以提取结构 氢卟啉的振动光谱信息， proteins. (2)本文研究了三种不同结构的π-阳离子和π-阴离子自由基的RR和IR光谱， 将表征各种卟啉和氢化卟啉。 将对这些物种进行正常坐标计算 用传统的和半经验的量子力场 方法. 各种金属还原态的振动和EPR谱 氢卟啉，例如Fe（I）和Ni（I）的络合物，也将 接受检查。 这些研究的目的是描述 结构和电子扰动诱导的添加或 去除电子。 对影响的定量评估 需要氧化/还原（但通常不可用） 为了从光谱中提取结构信息， 蛋白质中的氧化/还原四吡咯中间体。 (3)本文研究了一系列中性， 氧化和还原的卟啉和氢化卟啉二聚体， 三聚体[结构Ln（环）2、（环）Ln（环'）和Ln 2（环）3]将 接受检查。 这些研究的目的是确定 强相互作用对电子性质的影响 的复杂性，并提供一个基础，评估如何， 电子通信可以介导能量和/或电子 在蛋白质中的四吡咯修复基团之间转移。