Models for the FeMo-Cofactor of Nitrogenase

该项目的目标是在无机，生物无机 和有机化学计划是合成和 表征由聚簇组成的化合物 钼、铁和硫原子。这些集群与 铁-钼辅因子，通常称为FeMo-co， 固氮酶这个辅因子，它有一个当前的 未知的结构，构成了酶的关键部分， 活性部位需要对目标化合物进行研究， 为了评估这些方面的结构和化学 FeMo-co的性质，这是必不可少的“固定”的 大气中的氮通过酶的还原。 固氮酶催化一种最复杂的多电子 生物学中的转移反应， 其活性中心结构和反应活性是重要的 化学和生物化学的重要性。此外，催化剂 类似于活性中心的簇可能是一种强有力的催化剂 进行各种化学转化。 系统地合成高核度的Mo-Fe-S团簇， 被探索。重点将放在控制 在氧化过程中发生的结构重组 脱羰反应，以制备新的Mo-S-Fe 可以在结构上模拟FeMo-Co的簇， 结合作为固氮酶底物的小分子， 二氮还原抑制剂。合成物种将 以化学和物理方法表征， 反应性将进行调查，重点是 对不同金属反应性的系统检测 在给定的集群中。

The objective of this project in the Inorganic, Bioinorganic and Organometallic Chemistry Program is the synthesis and characterization of compounds consisting of clusters of molybdenum, iron and sulfur atoms. Such clusters are related to the iron-molybdenum cofactor, familiarly known as FeMo-co, of the enzyme nitrogenase. This cofactor, which has a currently unknown structure, constitutes a key portion of the enzyme's active site. Studies of the target compounds are needed in order to assess those aspects of the structural and chemical properties of FeMo-co which are essential to the "fixing" of atmospheric nitrogen through reduction by the enzyme. Nitrogenase catalyzes one of the most complex multi-electron transfer reactions in biology, so that understanding the structure and reactivity of its active site is of fundamental chemical and biochemical importance. Further, a catalytic cluster resembling the active site may be a powerful catalyst for a variety of chemical transformations. Systematic syntheses of high nuclearity Mo-Fe-S clusters will be explored. Emphasis will be placed on controlling the structural reorganizations that occur during oxidative decarbonylation reactions in order to prepare new Mo-S-Fe clusters that may mimic FeMo-co structurally and which will bind small molecules that are nitrogenase substrates or inhibitors in dinitrogen reduction. The synthetic species will be characterized by chemical and physical methods, and their reactivities will be investigated, with emphasis on a systematic examination of the reactivity of the different metal sites within a given cluster.