In the next grant period we will focus on understanding the Mo-catalyzed reduction in as much detail as possible, and in particular, what is the circumstance that leads to a breakdown in catalytic turnover of dinitrogen to ammonia. In the process we want to determine to what extent the successful system resembles the reduction of dinitrogen by the natural FeMo nitrogenase, and therefore attempt to build a case indirectly for or against reduction of dinitrogen at Mo in the natural FeMo system. Part of this effort will consist of catalytic reduction of substrates other than dinitrogen under conditions where dinitrogen is reduced in the well-defined system. We will continue to design new trianionic triamidoamine ligands that would allow reduction of dinitrogen under mild conditions at molybdenum, and we want to expand the chemistry of triamidoamine ligands to iron and ruthenium. We also want to design dianionic and monoanionic ligands for vanadium, iron, and ruthenium and want to explore methods of incorporating nitrogen into organic molecules, either directly, or via reactions that are linked to ammonia formation. The reduction of dinitrogen to ammonia is perhaps the most complex metalloenzyme-catalyzed process in nature and is essential for all life. To learn how dinitrogen reduction can be accomplished under mild conditions with a well-defined catalyst is one of the grand challenges. In the long run a reduction at room temperature and pressure could lead to an enormous savings in energy for ammonia production and to an understanding of catalytic principles that may help us design other catalytic processes or understand other catalytic reactions in biology.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
Project #
Application #
Study Section
Macromolecular Structure and Function A Study Section (MSFA)
Program Officer
Fabian, Miles
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Massachusetts Institute of Technology
Schools of Arts and Sciences
United States
Zip Code
Sharma, Ajay; Roemelt, Michael; Reithofer, Michael et al. (2017) EPR/ENDOR and Theoretical Study of the Jahn-Teller-Active [HIPTN3N]MoVL Complexes (L = N-, NH). Inorg Chem 56:6906-6919
Kinney, R Adam; McNaughton, Rebecca L; Chin, Jia Min et al. (2011) Protonation of the dinitrogen-reduction catalyst [HIPTN3N]Mo(III) investigated by ENDOR spectroscopy. Inorg Chem 50:418-20
Kinney, R Adam; Hetterscheid, Dennis G H; Hanna, Brian S et al. (2010) Formation of {[HIPTN(3)N]Mo(III)H}(-) by heterolytic cleavage of H(2) as established by EPR and ENDOR spectroscopy. Inorg Chem 49:704-13
McNaughton, Rebecca L; Roemelt, Michael; Chin, Jia Min et al. (2010) Experimental and theoretical EPR study of Jahn-Teller-active [HIPTN(3)N]MoL complexes (L = N(2), CO, NH(3)). J Am Chem Soc 132:8645-56
Chin, J M; Schrock, R R; Müller, P (2010) Synthesis of diamidopyrrolyl molybdenum complexes relevant to reduction of dinitrogen to ammonia. Inorg Chem 49:7904-16
Reithofer, Michael R; Schrock, Richard R; Müller, Peter (2010) Synthesis of [(DPPNCH2CH2)3N]3- molybdenum complexes (DPP = 3,5-(2,5-Diisopropylpyrrolyl)2C6H3) and studies relevant to catalytic reduction of dinitrogen. J Am Chem Soc 132:8349-58
Hetterscheid, Dennis G H; Hanna, Brian S; Schrock, Richard R (2009) Molybdenum triamidoamine systems. Reactions involving dihydrogen relevant to catalytic reduction of dinitrogen. Inorg Chem 48:8569-77
Kupfer, Thomas; Schrock, Richard R (2009) Alkylation of dinitrogen in [(HIPTNCH(2)CH(2))(3)N]Mo complexes (HIPT = 3,5-(2,4,6-i-Pr(3)C(6)H(2))(2)C(6)H(3)). J Am Chem Soc 131:12829-37
Schrock, Richard R (2008) Catalytic reduction of dinitrogen to ammonia by molybdenum: theory versus experiment. Angew Chem Int Ed Engl 47:5512-22
McNaughton, Rebecca L; Chin, Jia Min; Weare, Walter W et al. (2007) EPR study of the low-spin [d(3);S =(1)/(2)], Jahn-Teller-active, dinitrogen complex of a molybdenum trisamidoamine. J Am Chem Soc 129:3480-1

Showing the most recent 10 out of 23 publications