Research Interest/Area of Expertise
Synthetic inorganic and organometallic chemistry, bioinorganic chemistry, ligand design, catalysis, small molecule activation
We are a synthetic inorganic group with research interests in the fields of organometallic chemistry, bioinorganic chemistry, and catalysis. Our projects are focused on the activation of small molecules crucial to the fields of energy and the environment. Our research involves ligand design, coordination chemistry with transition and main-group elements, and reactivity studies.
Our first project focuses on dinuclear metal centers capable of cooperative reactivity in the activation of heteroallenes. The motivation for this research comes from the need to develop efficient catalysts for CO2 reduction and storage. Due to its low price, high abundance, and detrimental environmental effects, CO2 is an attractive C1 building block for the synthesis of chemicals or fuels. Two reactions of CO2 are of interest to us: reductive coupling to give oxalate, and the reductive splitting to yield CO and [O]. Reductive coupling of CO2 provides the most direct pathway toward transformation of CO2 to C2 chemicals, and we are seeking to unravel key factors in the molecular chemistry of CO2 that enable its reductive coupling. Our hypothesis is that the C-C bond formation in the transformation of CO2 to oxalate can be facilitated via cooperative intramolecular catalysis at dinuclear metal centers engineered to undergo facile one-electron oxidation each. Oxalate is expected to bridge two metal centers, and the dinuclear topology of the catalyst should template its formation. We have synthesized two bimetallic platforms capable of binding oxalate inside the intramolecular cavity and are studying their catalytic reactivity.
We are also designing bimolecular catalysts for the reductive splitting of CO2 and other heteroallenes. Reductive splitting provides a direct path from CO2 toward liquid fuels. Nature employs a heterobimetallic system at the active site of Ni/Fe CODH to split CO2. We are exploring various homo- and heterobimetallic systems capable of carrying out the required two-electron reduction cooperatively.
Our second project involves the chemistry of low-coordinate first-row transition metal and main-group complexes containing very bulky alkoxide ligands. We are specifically targeting two-coordinate M(OR)2 species and three-coordinate M(OR)2(=X) species (M = Mn-Ni). The combination of high electronegativity and strong π-donor capability of the oxygen donor makes multiply-bonded ligands X (X = NR, N, O) at the mid- and late transition metals platforms strongly oxidizing. We are investigating the potential of these species as platforms for X group insertion into C-H bonds to form C-X-H products. We are also synthesizing low-valent main-group compounds coordinated by the alkoxide ligands, and studying their properties.
Students joining our lab will acquire expertise in synthesis, spectroscopy, and crystallography. Inert-atmosphere glovebox (or Schlenk line) techniques are at the core of our synthetic efforts, allowing us to prepare transition metal complexes. We also employ extensive organic synthesis to make our ligands. To characterize our products, we utilize a variety of spectroscopic techniques, among them multinuclear NMR, IR, UV-vis, and EPR spectroscopies. Structural information on the transition metal complexes is acquired by single-crystal X-ray diffraction. Redox properties of the transition metal catalysts are studied using cyclic voltammetry, and chromatographic techniques are used to determine the nature of the products of catalysis.
Education – Degrees, Licenses, Certifications
- B.Sc., Tel Aviv University, Israel, 2000
- Ph.D., Tel Aviv University, Israel, 2006
- Postdoctoral Associate, Harvard University, 2006-2009
- Postdoctoral Fellow, MIT, 2009-2011
Yousif, M.; Cabelof, A. C.; Lord, R. L.; Groysman, S. Synthesis of a Mononuclear, Non-Square-Planar Chromium(II) Bis(alkoxide) Complex and its Reactivity Toward Organic Carbonyls and CO2. Dalton Trans. 2016, 45, 9794-9804. (Part of the Special Issue - New Talent Americas; the Article is Featured on the Back Cover of the Issue)
Bellow, J. A.; Stoian, S. A.; van Tol, J.; Ozarowsky, A.; Lord, R. L.; Groysman, S. Synthesis and Characterization of A Stable High-Valent Cobalt Carbene Complex. J. Am. Chem. Soc. 2016, 138, 5531-5534.
Yousif, M.; Tjapkes, D. J.; Lord, R. L.; Groysman, S. Catalytic Formation of Asymmetric Carbodiimides at Mononuclear Chromium(II)/(IV) Bis(alkoxide) Complexes. Organometallics 2015, 34, 5119-5128.
Bellow, J. A.; Yousif, M.; Lord, R. L.; Groysman, S. Reactivity Modes of an Iron Bis(alkoxide) Complex with Aryl Azides: Catalytic Nitrene Coupling vs. Formation of Iron(III) Imido Dimers. Organometallics 2015, 34, 2917-2923.
Beattie, J. W.; White, D. S.; Bheemaraju, A.; Martin, P. D.; Groysman, S. Recyclable Chemosensor for Oxalate Based on Bimetallic Complexes of a Dinucleating Bis(iminopyridine) Ligand. Dalton Trans. 2014, 43, 7979-7986.
Bellow, J. A.; Martin, P. D.; Lord, R. L.; Groysman, S. Reductive Coupling of Azides Mediated by a Quasi-Two-Coordinate Iron(II) Bis(alkoxide) Complex. Inorg. Chem. 2013, 52, 12335-12337.
Bheemaraju A.; Beattie, J. W.; Lord, R. L.; Martin, P. D.; Groysman, S. Carbon Disulfide Binding at Dinuclear and Mononuclear Nickel Complexes Ligated by a Redox-Active Ligand: Iminopyridine Serving as an Accumulator of Redox Equivalents fo the Activation of Heteroallenes. Chem. Commun. 2012, 48, 9595-9597.
CHM 8090 Advance Topics in Inorganic Chemistry, 1-3 credit hours W2016
CHM 1240 Organic Chemistry I, 4 credit hours F2016
CHM 4850/8850 Frontiers in Chemistry, 1 credit hours F2016