Spontaneous Ammonia Oxidation Through Coordination Induced Bond Weakening in Molybdenum Complexes of a Dianionic Pentadentate Ligand Platform

09 March 2022, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Ammonia oxidation catalyzed by molecular compounds is of current interest as a carbon free source of dihydrogen. Activation of N-H bonds through coordination to transition metal centers is a key reaction in this process. We report the substantial activation of ammonia through via reaction with low valent Mo complexes of a diborate pentadentate ligand system. Spontaneous loss of hydrogen atoms from (B2Pz4Py)Mo(II)-NH3 at room temperature to produce H2 and the dinuclear -nitrido compound (B2Pz4Py)Mo-N-Mo(B2Pz4Py) is observed due to substantial N-H bond weakening upon coordination to Mo. Mechanistic details are supported through the experimental observation characterization of terminal amido, imido and nitrido complexes and density functional theory computations. The generally under-appreciated role of bridging nitrido intermediates is revealed and discussed, providing guidance for further catalyst development for this process.


ammonia oxidation
bond activation
Density Functional Theory
ligand design


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.