Narrow Results

Transformation of methane, the most abundant and the least reactive compound of natural gas to valuable products is one of the most difficult chemical problems of great practical importance. In Nature, methane monooxygenase enzymes transform methane to methanol in water under physiological conditions. However, chemical analogs for such a transformation are unknown. Here, we show the mild and efficient aqueous oxidation of methane by hydrogen peroxide, an ecologically and biologically relevant oxidant catalyzed by supported μ-nitrido diiron phthalocyanine dimer, (FePc^tBu₄)₂N. This bio-inspired complex containing a stable Fe–N–Fe motif catalyzes the oxidation of methane to methanol which is further transformed to formaldehyde and formic acid as is demonstrated using ¹³CH₄ and ¹⁸O labelling. (FePc^tBu₄)₂N-H₂O₂ system shows a high activity in the oxidation of benzene to phenol which occurs via formation of benzene oxide and exhibits NIH shift typically accociated with biological oxidation. Mechanistic features of oxidation of methane and benzene as well as detected intermediate hydroperoxo- and high valent oxo diiron complexes support an O-atom transfer reaction mechanism relevant to bio-oxidation.

Some people think that carbon and sustainable development are not compatible. This textbook shows that carbon dioxide (CO₂) from the air and bio-carbon from biomass are our best allies in the energy transition, towards greater sustainability. We pose the problem of the decarbonation (or decarbonization) of our economy by looking at ways to reduce our dependence on fossil carbon (coal, petroleum, natural gas, bitumen, carbonaceous shales, lignite, peat). The urgent goal is to curb the exponential increase in the concentration of carbon dioxide in the atmosphere and hydrosphere (Figures 1.1 and 1.2) that is directly related to our consumption of fossil carbon for our energy and materials The goal of the Paris agreement (United Nations COP 21, Dec. 12, 2015) of limiting the temperature increase to 1.5 degrees (compared to the pre-industrial era, before 1800) is becoming increasingly unattainable (Intergovermental Panel on Climate Change (IPCC), report of Aug. 6, 2021). On Aug. 9, 2021 Boris Johnson, prime minister of the United Kingdom, declared that coal needs to be consigned to history to limit global warming. CO₂ has an important social cost…