Abstract
We have been able to reduce dinitrogen selectively and catalytically to ammonia at 1 atm and room temperature with protons and electrons. The reduction takes place at a single molybdenum center that is sterically protected against bimetallic decomposition reactions with meta-terphenyl-substituted triamidoamine ligands such as [(HIPTNCH2CH2)3N]3- where HIPT is hexaisopropyl-metaterphenyl. The proton source is ({2,6-lutidinium}{BAr'4}; Ar' = 3,5-(CF3)2C6H3) and the reductant is decamethyl chromocene.
The reducing equivalents make either ammonia (~60% from dinitrogen) or dihydrogen. All evidence suggests that N2 is being reduced at a single Mo center in which the oxidation state of the metal varies between Mo(III) and Mo(VI). Similar [(HIPTNCH2CH2)3N]3- complexes of tungsten, chromium, vanadium, and iron fail to yield any catalytic turnover of dinitrogen to ammonia.
The reducing equivalents make either ammonia (~60% from dinitrogen) or dihydrogen. All evidence suggests that N2 is being reduced at a single Mo center in which the oxidation state of the metal varies between Mo(III) and Mo(VI). Similar [(HIPTNCH2CH2)3N]3- complexes of tungsten, chromium, vanadium, and iron fail to yield any catalytic turnover of dinitrogen to ammonia.