High-Valent Metal Tetrapyrroles for Surface-Supported Catalysis

四氢吡咯的大环为催化活性金属离子提供了自然界最广泛的配位位置之一。金属配位和卟啉是这类天然丰富的催化分子中最著名的成员。易于获取、坚固耐用和易于调节的特性使金属四氢吡咯成为催化剂、治疗药物、体内生物标记物或染料敏化光伏电池等先进系统的关键组件。它们在高氧化态(如+III、+IV和+V)中稳定金属离子的特性赋予了它们选择性催化活性，使其具有潜在的新应用前景，如通过Mn(III)、Fe(III)、Au(III)或Ga(III)消除肿瘤和预防动脉粥样硬化。最近的液相研究表明，金属配位对小分子(如O2和CO2)的活化具有很高的潜力。几十年来，腐蚀剂的化学在很大程度上仍未得到开发，因为严重的合成障碍直到20世纪90年代末才被克服，到目前为止，几乎所有的研究都是在液态进行的。因此，关于固体表面支持的腐蚀剂的电子性质、构象和功能的基础知识仍有待探索。我们的建议涉及到由技术上相关的金属和半导体表面(Au，Si)支撑的基于Corole的试剂系统的研究、表征和开发，以提高小分子的活性。我们将重点放在精选的金属配位上，这些金属配位被认为是在液相中选择性地还原O2和CO2的潜在催化分子。作为比较的参考，我们将同时研究相关的卟啉络合物。通过使用定义良好的表面模板，不仅有助于高价中心金属离子的期望的稳定，而且还可以作为潜在的技术平台，以期提高催化性能。我们将全面描述决定特定催化活性的基本性质和过程。我们的建议是来自奥地利和德国的四个互补研究小组之间以反馈为导向的跨学科合作，这些小组在实验和理论物理以及合成和分析化学方面具有专门知识。在已有合作的基础上，我们从第一性原理出发，结合最先进的模型计算，进行多技术协同实验研究(低温扫描隧道显微镜；光电子、X射线吸收、磁共振和光学光谱；电化学)。我们的长期愿景是控制在技术相关的表面模板上负载的功能化金属定位角色和-卟啉，以选择性地激活小分子。

The macrocycle of tetrapyrroles provides one of nature’s most versatile coordination sites for catalytically active metal ions. Metallocorroles and porphyrins are the best known members of this class of naturally abundant catalytic molecules. The facile access, robustness, and easily tunable properties have established metallotetrapyrroles as key components in advanced systems like catalysts, therapeutics, in‐vivo biomarkers, or dye‐sensitized photovoltaic cells. Their characteristic ability of stabilizing metal ions in high oxidation states such as +III, +IV and +V bestows them selective catalytic activity for reactive pathways prospective for novel applications such as, e. g., tumor elimination via Mn(III), Fe(III), Au(III) or Ga(III) and atherosclerosis prevention. Recent liquid‐phase investigations have indicated a high potential of metallocorroles for small‐molecule activation (e. g. O2 and CO2). The chemistry of corroles remained largely undeveloped for decades because of severe synthetic obstacles that were overcome not before the late 1990s and, so far, literally all studies have been conducted in liquid phase. Thus, the fundamental knowledge on the electronic properties, conformation and functionality of corroles supported on solid surfaces remains to be explored.Our proposal concerns the investigation, characterization and development of corrole‐based agent systems supported by technologically relevant metal and semiconductor surfaces (Au, Si) for improved small‐molecule activation. We focus on well‐selected metallocorroles that are regarded as prospective catalytic molecules for the selective O2 and CO2 reduction in the liquid phase. As a reference for comparison, we will simultaneously investigate the related porphyrin complexes. An improved catalytic performance is aspired by employing well‐defined surface templates that assist not only the desired stabilization of high‐valent central metal ions, but act as prospective technological platforms, as well. We shall comprehensively characterize the elementary properties and processes that determine specific catalytic activities. Our proposal is an interdisciplinary feedback‐oriented collaboration between four complementary research groups from Austria and Germany with dedicated expertise in experimental and theoretical physics as well as synthetic and analytic chemistry. Based on already existing collaborations, we perform concerted experimental multi‐technique investigations (low temperature scanning tunneling microscopy; photoelectron‐, X-ray absorption, magnetic‐resonance‐ and optical spectroscopy; electrochemistry) in combination with state‐of‐the‐art model calculations from first principles. Our long term vision is a control of functionalized metallocorroles and ‐porphyrins supported on technologically relevant surface templates for selective small‐molecule activation.