Activation of N2O with first-row transition metal complexes
Researcher in charge: Anna Company
Oxidation reactions are one of the most important chemical transformations applied in industry because the use of fossil hydrocarbons usually requires their initial functionalization via oxidation to allow their posterior transformation into value-added oxygen-containing chemicals. Current environmental considerations require the development of mild oxidation technologies based on transition metal catalysts together with cheap and non-toxic oxidants such as air, molecular oxygen or peroxides. In this line, there is an increasing interest in the use of N2O as an oxidizing reagent as it only generates unproblematic N2 as waste. Although N2O is a minor component of the earth atmosphere (319 ppb), it has been identified as a major environmental concern because it is ~300 times more potent as a greenhouse gas than CO2 and it is involved in the depletion of stratospheric ozone. Its concentration is increasing every year largely due to anthropogenic sources that include manufacturing, fossil fuel use and agricultural activities. Thus, the use of nitrous oxide as oxidant would be a very interesting application of this waste gase. However, N2O has been long considered an inert molecule because, despite being thermodynamically a potent oxidant, it is kinetically very stable. Taking inspiration from metalloenzymes (nitrous oxide reductase), reaction with transition metals has been identified as a good strategy to overcome these kinetic barriers, albeit progress in this field has been rather limited.
In the present project we aim to achieve the activation of nitrous oxide with well-designed first-row transition metal (TM) complexes. Carefully chosen ligands will be used to prepare metal complexes with electron-rich metal centers suitable to attain the reductive activation of N2O. Understanding the mechanisms of nitrous oxide activation and finding new applications for the use of N2O as oxidant in organic reactions under mild conditions are the main aims of the present project.