Synthetic Analogs of Nickel Hydrogenases

本研究将探索三价镍在配位环境中的反应性和结构化学，这被认为是模仿镍氢化酶的配位环境。这些酶负责氢的可逆转化，这是趋化养和光养细菌在厌氧代谢中必不可少的转化。镍位点的配位环境因生物的不同而不同。一个共识协调圈有2-4个氮或氧供体和1-3个硫或硒供体围绕镍。稳定镍的三价氧化态将是一个重大的合成挑战，因为这些系统倾向于通过二硫化物的形成和伴随的金属还原来降解。设计并合成了一类新的三氮杂环壬烷配体来解决这一问题。其他金属在这种独特配位环境中的掺入也将被研究。该奖项是Daniel Stack博士化学博士后研究奖学金的启动基金，以支持他在斯坦福大学的研究。斯塔克博士的研究重点是镍氢化酶类似物的设计、合成和表征。

This research will explore the reactivity and structural chemistry of tervalent nickel in coordination environments which are thought to mimic those found for nickel hydrogenase enzymes. These enzymes are responsible for the reversible conversion of of hydrogen--an essential conversion in anaerobic metabolism for both chemotrophic and phototrophic bacteria. The coordination environment of the nickel site varies with different organisms. A consensus coordination sphere has 2-4 nitrogen or oxygen donors and 1-3 sulphur or selenium donors around nickel. Stabilization of nickel in its tervalent oxidation state will be a significant synthetic challenge due to the propensity of these systems to degrade by disulfide formation and concomitant metal reduction. A new class of ligands based on triazacyclononane will be designed and synthesized to circumvent this problem. The incorporation of other metals in this unique coordination environment will also be investigated. %%% This award is made as the starter grant increment of Dr. Daniel Stack's Postdoctoral Research Fellowship in Chemistry in support of his research at Stanford University. The thrust of Dr. Stack's research is the design, synthesis and characterization of analogs of nickel hydrogenases.