Marcetta Darensbourg
  • Distinguished Professor
  • Davidson Chair in Science
Research Areas
  • Inorganic

Research Interests

Bio-inspired Catalysts for Hydrogen Production: The ultimate, home-run, goal of our work is to synthesize and develop a robust, highly active hydrogen-producing catalyst comprised of earth-abundant transition metals within a ligand environment that is inspired by the biological Figure 3hydrogenase (H2ase) enzyme active sites. Progress in precise structural modeling of the illusive "rotated" structure displayed in the as-isolated, mixed-valent FeIIFe state in the past decade has permitted in depth analysis of electronic structure by Mö ssbauer, EPR (ENDOR), and computational chemistry. We can conclude why this unique organometallic structure, first spotted in biology (but now achieved by distinct but convergent synthetic strategies in three laboratories) is stable! The square pyramid-inverted square pyramid structures result from sufficient disruption of Fe—Fe bond order in the FeIFeI precursors that permits steric factors to dominate and enforce rotation of one square pyramid relative to the other.

Still, questions remain regarding functional matches: the need for two metals in the [FeFe]- and [NiFe]-H2ase active sites; whether additional collaborative redox activity is required; or whether innocent metallodithiolate ligands control the redox levels of a single metal site. These questions are being addressed by analysis of advanced synthetic analogues that have evolved from 1st and 2nd generation electrocatalysts, and, in collaborations, by comparison to spectroscopic signals from the [FeFe]-H2ase active site.

New electrocatalysts for hydrogen production: The connection between the Fe(NO)2 unit and the Fe(CX)3 (X = O or N) unit found in hydrogenase enzyme active sites offers opportunity for design of new catalysts, one of which is shown. In this regard we explore the ability of N2S2 metal complexes to bind as metallodithiolate ligands to various metal acceptors. The properties of such complexes vary The connection of these to light harvesting molecules for dye sensitized, sacrificial electron donor, hydrogen production is also of interest.

When Iron Meets Nitric Oxide: Good Chemistry, Intriguing Biology. The affinity of iron for diatomic molecules, O2, CO, N2, and NO, is central to the most important of life processes, including those of human physiology. Figure 6In this research area we target synthetic chemistry involving dinitrosyl iron complexes (DNICs) that serve as biomimetics of products of FeS cluster degradation by excesses of NO, or as derived from the chelatable iron pool (CIP) in cells. The electronic ambivalence of the DNIC unit is expressed in the ease with which it interconverts between oxidized and reduced forms, {Fe(NO)2}9 and {Fe(NO)2}10, respectively (Enemark/Feltham notation), and serves as impetus to explore analogous reactions known to involve the CuII/CuI redox couple. The accessory ligands which stabilize one redox level over the other, including N-heterocyclic carbenes as histidine mimics, and properties of DNIC derivatives are explored.

Educational Background

  • B. S., 1963, Union College Kentucky
  • Ph. D., 1967, University of Illinois at Urbana

Awards & Honors

  • Willard Gibbs Medal Award, American Chemical Society – Chicago Section (2019)

  • SEC Professor of the Year (2018)

  • Oakley R. Vail Lecturer, Wake Forest University (2018)

  • Kosolapoff Award, Auburn University (2018)

  • Cecil and Ida Green Honors Professor, Texas Christian University (2018)

  • Member of the National Academy of Sciences (2017)

  • American Chemical Society Award in Organometallic Chemistry (2017)

  • Texas A&M University College of Science Undergraduate Research Mentoring Award (2016)

  • University of California, Los Angeles M. Frederick Hawthorne Endowed Lecturer (2016)

  • Royal Society of Chemistry Fellows (2014)

  • Riley Schaeffer Endowed Lecturer (2014)

  • Gagliardi Distinguished Lecturer (2014)

  • Fred Basolo Medal (2013)

  • John C. Bailar, Jr. Medalist (2013)

  • Texas A&M Association of Former Students Award for Graduate Mentoring (2012)

  • American Academy of Arts & Sciences Fellows (2011)

  • Texas A&M Chapter of Sigma Xi - Distinguished Scientist Award (2011)

  • American Chemical Society Fellows (2009)

  • The Robert A. Welch Lectureship Program (2007-2008)

  • American Chemiscal Society Award for Distinguished Service in the Advancement of Inorganic Chemistry sponsored by the Mallinckrodt Specialty Chemicals Company (1995)

  • Texas A&M Association of Former Students Faculty Distinguished Achievement Award in Research (University-Level, 1995)

  • American Chemical Sociery Southwest Region Award (1998)

Selected Publications

  • (M287) Site specific redox properties in ligand differentiated di-nickel complexes inspired by the acetyl CoA synthase active site. Manuel Quiroz, Manish Jana, Kaiyang Liu, Nattamai Bhuvanesh, Michael B. Hall and Marcetta Y. Darensbourg*. Dalton Trans.,2024, Advance Article. DOI:/10.1039/D4DT00306C

    (M286) Development of (NO)Fe(N2S2) as a Metallodithiolate Spin Probe Ligand: A Case Study Approach. Manuel Quiroz and Marcetta Y. Darensbourg*. Acc. Chem. Res., 2024, 57, 831–844. DOI:10.1021/acs.accounts.3c00667

    (M285) A single carbon atom controls the geometry and reactivity of CoII(N2S2) complexes. Manish Jana, Manuel Quiroz and Marcetta Y. Darensbourg*. Chem. Commun. 2024, 60, 1128-1131. DOI:10.1039/D3CC05394F

    (M284) Bond Trading: Intramolecular Metal and Ligand Exchange within a NO/Ni/Co Complex. Manish Jana, Xueyan Zheng, Trung Le, Manuel Quiroz, Paulina Guererro-Almaraz, Donald J. Darensbourg, Marcetta Y. Darensbourg*. Adv. Sci., 2024, 11, 2307113. DOI: 10.1002/advs.202307113

    (M283) Magnetic coupling between Fe(NO) spin probe ligands through diamagnetic NiII, PdII and PtII tetrathiolate bridges. Manuel Quiroz, Molly M. Lockart, Shan Xue, Dakota Jones, Zachary Martinez, Yisong Guo, Brad S. Pierce, Kim R. Dunbar,* Michael B. Hall* and Marcetta Y. Darensbourg*. Chem. Sci., 2023, 14, 9167-9174. DOI: 10.1039/D3SC01546G

    (M282) Sulfur Lone Pairs Control Topology in Heterotrimetallic Complexes: An Experimental and Theoretical Study. Paulina Guerrero-Almaraz, Manuel Quiroz, David R. Rodriguez, Manish Jana, Michael B. Hall*, and Marcetta Y. Darensbourg* ACS Org. Inorg. Au , 2023, 3, 393-402. DOI: 10.1021/acsorginorgau.3c00025

    (M281) Chirality-Guided Isomerization of Mn2S2 Diamond Core Complexes: A Mechanistic Study. Trung Le, Hao Nguyen, Heather A. Arnold, Donald J. Darensbourg and Marcetta Y. Darensbourg. Inorg. Chem.,2022, 61, 16404-16413. DOI:10.1021/acs.inorgchem.2c02460

    (M280) Structural Analysis of Heteropolymetallic Complexes: a Chiral Pinwheel {Cr[Ni(N2S2)]3}3+ and the {trans-(MeCN)Cr(NO)[Ni(N2S 2)]2}2+ Basket. Paulina Guerrero-Almaraz, Manuel Quiroz, and Marcetta Y. Darensbourg. Polyhedron. 2022,VOL. 224 DOI: 10.1016/j.poly.2022.116018

    (M279) Cooperative redox and spin activity from three redox congeners of sulfur-bridged iron nitrosyl and nickel dithiolene complexes. Manuel Quiroz, Molly M. Lockhart, Mohamed R. Saber, Shaik Waseem Vali, Lindy C. Elrod, Brad S. Pierce, Michael B. Hall, and Marcetta Y. Darensbourg. 2022, VOL. 119 . DOI: 10.1073/pnas.2201240119

    (M278) Organometallic Chemistry Control of Hydrogenases. Marcetta Y. Darensbourg, Erica Lyon Oduaran, Shengda Ding, Allen M. Lunsford, K. Dilshan Kariyawasam Pathirana, Pokhraj Ghosh, Xuemei Yang, contribution in Enzymes for Solving Humankind's Problems. Eds. Moura J.J.G., Moura I., Maia L.B., Springer, Cham. 2021, 275-300. DOI: 10.1007/978-3-030-58315-6_10

    (M277) Zinc thiotropolone combinations as inhibitors of the SARS-CoV-2 main protease. Christopher R. DeLaney, Y. Sheng, D. Chase Pectol, E. Vatansever, H. Zhang, N. Bhuvanesh, I. Salas, W. R. Liu, C. F. Fierke, Marcetta Y. Darensbourg. Dalton Trans. 2021, 50, 12226-12233. DOI: 10.1039/D1DT02499J

    (M276) Dinitrosyl iron complexes (DNICs) as inhibitors of the SARS-CoV-2 main protease. D. Chase Pectol, Christopher R. DeLaney, J. Zhu, D. M. Mellott, A. Katzfuss, Z. W. Taylor, T. D. Meek, Marcetta Y. Darensbourg. Chem. Comm. 2021, 57, 67, 8352-8355. DOI: 10.1039/D1CC03103A

    (M275) Linear and Bent Nitric Oxide Ligand Binding in an Asymmetric Butterfly Complex: CoMoCo′. Paulina Guerrero-Almaraz, Manuel Quiroz, Joseph H. Reibenspies and Marcetta Y. Darensbourg. Inorg. Chem. 2021 DOI: 10.1021/acs.inorgchem.1c00987

    (M274) Self-Assembled Nickel-4 Supramolecular Squares and Assays for HER Electrocatalysts Derived Therefrom. Xuemei Yang, Christopher R. DeLaney, Kyle T. Burns, Lindy C. Elrod, Wenting Mo, Haley Naumann, Nattamai Bhuvanesh, Michael B. Hall and Marcetta Y. Darensbourg. Inorg. Chem. 2021, 60, 10, 7051-7061 . DOI:10.1021/acs.inorgchem.0c03613

    (M273) Effects of Glutathione and Histidine on NO Release from a Dimeric Dinitrosyl Iron Complex (DNIC). D. Chase Pectol, Sarosh Khan, Mahmoud Elsabahy, Karen L. Wooley, Soon-Mi Lim, and Marcetta Y. Darensbourg. Inorg. Chem. 2020, 11, 9366-9377. DOI: 10.1021/acs.inorgchem.0c02196

    (M272) The Roles of Chalcogenides in O2 Protection of H2ase Active Sites. Xuemei Yang and Marcetta Y. Darensbourg. Chem. Sci. 2020, 11, 9366-9377. DOI: 10.1039/D0SC02584D