ACERT Highlights: Recent Highlights

National Institute of General Medical Sciences
	National Biomedical Resource for Advanced ESR Spectroscopy

Recent Highlights

Lewis Acid-Assisted Reduction of Nitrite to Nitric and Nitrous Oxide via the Elusive Nitrite Radical Dianion

Reduction of nitrite anions (NO_2-) takes place in a myriad of environments such as in the soil as part of the biogeochemical nitrogen cycle as well as in acidified nuclear waste. Nitrite reduction typically takes place within the coordination sphere of a redox active transition metal. Lewis acid coordination, however, can dramatically modify the reduction potential of this polyoxoanion to allow for reduction under non-aqueous conditions (-0.74 V vs. NHE). This strategy enables the isolation of a borane-capped nitrite dianion (NO₂^2-) along with its spectroscopic study consistent with reduction to the N(II) oxidation state. Protonation of the nitrite dianion results in facile loss of nitric oxide (NO) while reaction of the nitrite dianion with nitric oxide results in disproportionation to nitrous oxide (N₂O) and nitrite, connecting three redox levels in the global nitrogen cycle.

Publication: V. Hosseininasab, I.M. DiMucci, P. Ghosh, J.A. Bertke, S. Chandrasekaran, C.J. Titus, D. Nordlund, J.H. Freed, K.M. Lancaster, and T.H. Warren. In press (Nature Chemistry; 2022).

Figure: a, 298 K solution continuous wave (CW) X-band (9.3886 GHz) EPR spectrum of ¹⁴N-4 (9.7249 GHz). b, Solution CW X-band EPR spectrum of ¹⁵N-4. c, 96 K frozen solution CW X-band (9.2710 GHz) EPR of ¹⁴N-4. d, 10 K field-swept echo-detected Q-band (33.9544 GHz) EPR of ¹⁴N-4. Experimental data are in black, simulations are red. e, Smoothed partial fluorescence yield detected N K-edge XAS of 3 (black) and 4 (red). Raw data are in gray. f, B3LYP/def2-TZVP(-f) calculated spin density plots (isovalue 0.002 au) of the dianion in 4 and geometry-optimized NO₂^2-.

Valiallah Hosseininasab (Department of Chemistry, Georgetown University, Washington, DC)
Ida M. DiMucci (Chemistry and Chemical Biology, Cornell University, Ithaca, NY)
Pokhraj Ghosh (Department of Chemistry, Georgetown University, Washington, DC)
Jeffery A. Bertke (Department of Chemistry, Georgetown University, Washington, DC)
Siddarth Chandrasekaran (Chemistry and Chemical Biology, Cornell University, Ithaca, NY)
Charles J. Titus (Department of Physics, Stanford University, Stanford, CA)
Dennis Nordlund (Stanford Synchrotron Radiation Lightsource (SLAC) National Accelerator Laboratory, Menlo Park, CA)
Jack H. Freed (ACERT, Chemistry and Chemical Biology, Cornell University, Ithaca, NY)
Kyle M. Lancaster (Chemistry and Chemical Biology, Cornell University, Ithaca, NY)
T.H. Warren (Department of Chemistry, Georgetown University, Washington, DC)

Site Map

Home

About ACERT
ACERT News
Personnel

Research
   Available Resources
   Technologies
   Research Highlights
   Collaborations

Outreach
   Dissemination
   Training/Workshops
   Publications
   Useful Links

ACERT is supported by grant 1R24GM146107 from the National Institute of General Medical Sciences (NIGMS), part of the National Institutes of Health.

National Biomedical Resource for Advanced ESR Spectroscopy

Baker Laboratory of Chemistry
259 East Ave.
Ithaca, NY 14853

National Institute of
General Medical Sciences