The long-term objective of this research is to determine how molecular nitrogen can be reduced to ammonia catalytically at room temperature employing a transition metal complex and protons and electrons. The short-term objective is to investigate the chemistry of complexes containing molybdenum or tungsten in a relatively high oxidation state (4+,5+,6+) or rhenium (5+,6+,7+) that are relevant to dinitrogen reduction, especially monomeric complexes containing N2Hx and NHy ligands. Specific objectives for the next grant period include (i) an in depth study of monomeric complexes containing the MCp*Me3 fragment (M = Mo or W) and hydrazido(1-) or hydrazido(2-) ligands, or hydrazine, or ammonia; (ii) synthesis and study of related complexes containing the ReCp*Me3 core; and (iii) synthesis and study of other types of high oxidation state complexes to which dinitrogen, hydrazido, hydrazine, or ammonia ligands will bind to form complexes relevant to catalytic reduction of dinitrogen. In addition to synthesis we will focus on electrochemistry, 15N labelling and mechanistic studies, x-ray studies of proven intermediates in N2 reduction sequences, and the design of a catalytic homogeneous dinitrogen reduction system.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM031978-11
Application #
2176385
Study Section
Metallobiochemistry Study Section (BMT)
Project Start
1983-04-01
Project End
1994-11-30
Budget Start
1993-12-01
Budget End
1994-11-30
Support Year
11
Fiscal Year
1994
Total Cost
Indirect Cost
Name
Massachusetts Institute of Technology
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
City
Cambridge
State
MA
Country
United States
Zip Code
02139
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

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