Homogeneous hydrocarbon oxidation using nitrous oxide as a sustainable feedstock

一氧化二氮（N2 O）是一种强效温室气体，在大气中的半衰期为114年，全球变暖潜能值比二氧化碳大300倍，是21世纪世纪排放的主要臭氧消耗物质。作为一种丰富的可持续资源，N2 O作为氧化剂在化学制造中的使用是一个有吸引力的前景，释放环境友好的二氮N2，但受到这种气体的强大的三原子组成的阻碍。虽然在极端条件下应用非均相催化剂确实允许与N2 O进行反应，但此类系统是能量密集型的、非选择性的并且最终在商业上不可行。该项目将寻求建立通过均相过渡金属络合物活化N2 O的科学基础，最终目标是将这些发现转化为有影响力的催化应用。使用第9和10族金属配合物支持的强大mer-tridentate“钳”配体，完整的M-N2 O加合物的形成和向前的反应性将被利用，以获得基本的了解如何N2 O可以最有效地利用在化学合成中，与前景产生反应性的终端氧代/oxyl衍生物严格审查特别。从这些研究中产生的结构-性能和结构-活性关系将被利用，使新的催化剂的合理设计，并实现逐步变化的性能转换采用N2 O作为选择性烃氧化剂。甲烷升级为甲醇是一个值得注意的和工业上令人垂涎的转型，将成为目标，世界对甲醇的需求每年接近1亿公吨（MMSA数据）。在卓别林小组正在进行的实验工作的基础上，并与早期过渡元素的化学性质进行比较，该建议将系统地研究使用第9族和第10族金属钳形络合物活化N2 O，假设其导致反应性末端氧代/氧基衍生物的形成。使用实验（与卓别林）和计算（与Krämer）方法的协同组合，第9和10族金属催化剂目标将被研究，以建立结构-性能和结构-活性关系的基础上的N2 O的配位和活化。这些发现将被用来推动后续的催化剂设计，最有希望的线索将经过严格的实验检验。

Nitrous oxide (N2O) is a potent greenhouse gas, with a half-life of 114 years in the atmosphere and global warming potential 300 times greater than carbon dioxide, and the dominant ozone depleting substance emitted in the 21st century. As an abundant and sustainable resource, the use of N2O as an oxidant in chemical manufacture is an attractive prospect, liberating environmentally benign dinitrogen N2, but encumbered by the robust triatomic formulation of this gas. Whilst application of heterogenous catalysts under extreme conditions does permit reactions with N2O to be performed, such systems are energy intensive, unselective and ultimately not commercially viable. This project will seek to establish the science underpinning the activation of N2O by homogeneous transition-metal complexes with the ultimate objective of translating these findings into impactful catalytic applications. Using group 9 and 10 metal complexes supported by robust mer-tridentate 'pincer' ligands, the formation and onward reactivity of intact M-N2O adducts will be leveraged to gain fundamental understanding of how N2O can be most effectively exploited in chemical synthesis, with the prospect for generating reactive terminal oxo/oxyl derivatives rigorously examined in particular. The resulting structure-property and structure-activity relationships generated from these studies will be harnessed to enable the rational design of new catalysts and achieve step-changes in performance for transformations employing N2O as a selective hydrocarbon oxidant. The upgrading of methane to methanol is one notable and industrially coveted transformation that will be targeted, with world demand for methanol approaching 100 million metric tons annually (MMSA data).Building upon ongoing experimental work in the Chaplin group and drawing parallels with the chemistry of the early transition elements, this proposal will systematically investigate the activation of N2O using group 9 and 10 group metal pincer complexes, that is hypothesised to result in the formation of reactive terminal oxo/oxyl derivatives. Using a synergistic combination of experimental (with Chaplin) and computational (with Krämer) approaches, group 9 and 10 metal catalyst targets will be investigated to establish structure-property and structure-activity relationships underlying the coordination and activation of N2O. These findings will be harnessed to propel subsequent catalyst design, with the most promising leads rigorously examined experimentally.