Copper model complexes of lytic polysaccharide monooxygenases

LPMO是一类新的含铜酶，能够氧化约100 kcal/mol的C-H。这些酶的铜活性位点含有由“组氨酸支架”配位的铜，其中蛋白质的氨基末端用于与铜离子配位。这种协调在生物无机化学中是极其罕见的，许多问题被提出来，以什么样的作用，这组是在允许铜配合物产生高度氧化的物种。这个博士将集中在制备和研究两种类型的小分子配合物，并检查其光谱和结构特性的LPMO的上下文中。第一类络合物将含有NH 2或NH基团作为铜的配位组的一部分，以检查氢原子在铜离子的化学中是否重要。第二类将在配位集中包含去质子化的酰胺/胺，以检查这种类似的物质是否可以存在于LPMO中。在这两种情况下，复合物将进行光谱和结构研究。这些配合物的Cu（I）形式的反应性也将进行研究，以期了解更多关于类似的反应性LPMOs.The主要的光谱技术将是多频EPR，可见吸收光谱和磁性圆二色性。这些技术将增加与理论方法来解释相关的自旋哈密顿参数和轨道能量。后者将使用密度泛函计算来确定。可以预见，新的理论方法可能需要部署在EPR数据的解释铜配合物。因此，新的方法，使用密度泛函理论的能量旁边的总和状态微扰计算将被检查。

The LPMOs are a new class of copper-containing enzymes which are capable of oxidising C-H of around 100 kcal/mol. The copper active site of these enzymes contains the copper coordinated by a 'histidine brace' where the amino terminus of the protein is used to coordinate to the copper ion. Such coordination is extremely rare in bioinorganic chemistry and many questions are posed as to what the role of this group is in allowing the copper complex to generate highly oxidising species.This PhD will concentrate on preparing and studying two types of small molecule complexes and examining their spectroscopic and structural properties in the context of LPMOs. The first class of complexes will contain either an NH2 or and NH group as part of the copper's coordination set to examine whether the hydrogen atoms are important in the chemistry of the copper ion. The second class will contain deprotonated amide/amine in the coordination set to examine whether such a similar species could exist in LPMOs. In both cases the complexes will be studied spectroscopically and structurally. The reactivity of the Cu(I) forms of these complexes will also be studied, with a view to understanding more about the analogous reactivity in LPMOs.The principal spectroscopic techniques will be multi-frequency EPR, visible absorption spectroscopy and magnetic circular dichroism. These techniques will be augmented with a theoretical approach to interpreting the related spin-Hamiltonian parameters and the orbital energetics. The latter will be determined using density functional calculations. It is anticipated that new theoretical methods may need to be deployed in the interpretation of EPR data of Cu complexes. As such, new approaches which use DFT energetics alongside sum-over-states perturbative calculations will be examined.