A5009171255- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Ammonia Synthesis and Nitrogen Reduction
- CO2 Reduction Techniques and Catalysts
- Organometallic Complex Synthesis and Catalysis
- Asymmetric Hydrogenation and Catalysis
- Metalloenzymes and iron-sulfur proteins
- Carbon dioxide utilization in catalysis
- Chemical Synthesis and Characterization
- Metal complexes synthesis and properties
- Hydrogen Storage and Materials
- Inorganic Chemistry and Materials
- Crystallography and molecular interactions
- Synthesis and characterization of novel inorganic/organometallic compounds
- Risk and Safety Analysis
- Occupational Health and Safety Research
- Chemical Safety and Risk Management
- Nanomaterials for catalytic reactions
- Catalytic Cross-Coupling Reactions
- Chemical Synthesis and Reactions
- Coordination Chemistry and Organometallics
- Machine Learning in Materials Science
- Advanced Photocatalysis Techniques
- Catalysts for Methane Reforming
- Catalytic Alkyne Reactions
University of North Carolina at Chapel Hill
2017-2025
Stony Brook University
2025
Massachusetts Institute of Technology
2022
Georgia Institute of Technology
2017
Despite advances in the development of molecular catalysts capable reducing dinitrogen to ammonia using proton donors and chemical reductants, few electrocatalysts have been discovered. This Perspective considers prospects electrocatalyst based on a mechanism featuring cleavage N2 into metal nitride complexes. By understanding factors that control reactivity individual steps along electrochemical path, opportunities for new are identified. Ligand design principles facile binding, formation...
The direct scission of the triple bond dinitrogen (N2) by a metal complex is an alluring entry point into transformation N2 to ammonia (NH3) in molecular catalysis. Reported herein pincer-ligated rhenium system that reduces NH3 via well-defined reaction sequence involving reductive formation bridging complex, photolytic splitting, and proton-coupled electron transfer (PCET) reduction metal–nitride bond. new (PONOP)ReCl3 (PONOP = 2,6-bis(diisopropylphosphinito)pyridine) reduced under afford...
A new family of low-coordinate Co complexes supported by three redox-noninnocent tridentate [OCO] pincer-type bis(phenolate) N-heterocyclic carbene (NHC) ligands are described. Combined experimental and computational data suggest that the charge-neutral four-coordinate best formulated as Co(II) centers bound to closed-shell [OCO]2– dianions, general formula [(OCO)CoIIL] (where L is a solvent-derived MeCN or THF). Cyclic voltammograms reveal oxidations accessible at potentials below 1.2 V vs...
The conversion of metal nitride complexes to ammonia may be essential dinitrogen fixation. We report a new reduction pathway that utilizes ligating acids and metal–ligand cooperation effect this without external reductants. Weak such as 4-methoxybenzoic acid 2-pyridone react with complex [(H-PNP)RuN]+ (H-PNP = HN(CH2CH2PtBu2)2) generate octahedral ammine are κ2-chelated by the conjugate base. Experimental computational mechanistic studies reveal important role Lewis basic sites proximal...
The kinetics of hydride transfer from Re(Rbpy)(CO)3H (bpy = 4,4′-R-2,2′-bipyridine; R OMe, tBu, Me, H, Br, COOMe, CF3) to CO2 and seven different cationic N-heterocycles were determined. Additionally, the thermodynamic hydricities complexes type established primarily using computational methods. Linear free-energy relationships (LFERs) derived by correlating kinetic indicate that, in general, rate increases as driving force for reaction increases. Kinetic isotope effects range inverse...
Molybdenum complexes supported by tridentate pincer ligands are exceptional catalysts for dinitrogen fixation using chemical reductants, but little is known about their prospects electrochemical reduction of dinitrogen. The viability N2 binding and splitting a molybdenum(III) complex, (pyPNP)MoBr3 (pyPNP = 2,6-bis(tBu2PCH2)-C5H3N)), established in this work, providing foundation detailed mechanistic study electrode-driven formation the nitride complex (pyPNP)Mo(N)Br. Electrochemical kinetic...
The thioether-diphosphine pincer-ligated molybdenum complex, (PSP)MoCl3 (1-Cl3, PSP = 4,5-bis(diisopropylphosphino)-2,7-di-tert-butyl-9,9-dimethyl-9H-thioxanthene) has been synthesized as a catalyst-precursor for N2 reduction catalysis, with focus on an integrated experimental/computational mechanistic investigation. The...
The catalytic hydrogenation of carbon dioxide holds immense promise for applications in sustainable fuel synthesis and hydrogen storage. Mechanistic studies that connect thermodynamic parameters with the kinetics catalysis can provide new understanding guide predictive design improved catalysts. Reported here are thermochemical kinetic analyses a pincer-ligated rhenium complex (tBuPOCOP)Re(CO)2 (tBuPOCOP = 2,6-bis(di-tert-butylphosphinito)phenyl) catalyzes CO2 to formate faster rates at...
Hydride transfer catalysis is shown to be enabled by the nonspectator reactivity of a transition metal-bound low-symmetry tricoordinate phosphorus ligand. Complex 1·[Ru]+, comprising nontrigonal chelate (1, P(N(o-N(2-pyridyl)C6H4)2) and an inert metal fragment ([Ru] = (Me5C5)Ru), reacts with NaBH4 give metallohydridophosphorane (1H·[Ru]) P-H bond formation. 1H·[Ru] revealed potent hydride donor (ΔG°H-,exp < 41 kcal/mol, ΔG°H-,calc 38 ± 2 kcal/mol in MeCN). Taken together, 1·[Ru]+/1H·[Ru]...
A series of ruthenium(II) hydrido dinitrogen complexes supported by pincer ligands in different formal oxidation states have been prepared and characterized. Treating a ruthenium dichloride complex the ligand bis(di-tert-butylphosphinoethyl)amine (H-PNP) with reductant or base generates new five-coordinate cis-hydridodinitrogen each containing forms ligand. Further transformations provide access to first isostructural set featuring all six The conserved structure facilitates characterization...
Laboratory safety teams (LSTs), led by graduate student and postdoctoral researchers, have been propagating across the U.S. as a bottom-up approach to improving culture in academic research laboratories. Prior COVID-19 pandemic, LSTs relied heavily on in-person projects events. Additionally, committed Champions from ranks of professionals faculty were critical their operation continued expansion. As was case for many existing systems, global crisis served an operational stress test LSTs,...
The thioether-diphosphine pincer-ligated molybdenum complex, (PSP)MoCl3 (1-Cl3, PSP = 4,5-bis(diisopropylphosphino)-2,7-di-tert-butyl-9,9-dimethyl-9H-thioxanthene) has been synthesized as a catalyst-precursor for N2 reduction catalysis, with focus on an integrated experimental/computational mechanistic investigation. (PSP)Mo unit is isoelectronic the (PNP)Mo (PNP 2,6-bis(di-t-butylphosphinomethyl)pyridine) fragment found in family of catalysts to NH3 first reported 2011 by Nishibayashi and...
<div><div><div><p>The direct scission of the triple bond dinitrogen (N2) by a metal complex is an alluring entry point into transformation N2 to ammonia (NH3) in molecular catalysis. Reported herein pincer-ligated rhenium system that reduces NH3 via well-defined reaction sequence involving reductive formation bridging complex, photolytic splitting, and proton-coupled electron transfer (PCET) reduction metal-nitride bond. The new (PONOP)ReCl3 (PONOP = 2,6-...
The first mononuclear Au III PNP pincer complexes [PNP = bis(2‐diisopropylphosphinophenyl)amide] are reported. chloro complex [(PNP)Au(Cl)][OAc F ] (OAc OCOCF 3 ) was synthesized by microwave irradiation of a tetrachloroaurate salt and the neutral PN H P ligand. Dehalogenation with AgOAc afforded trifluoroacetate‐bound [(PNP)Au(OAc )][OAc ]. Both were characterized NMR spectroscopy X‐ray crystallography. Electronic absorption TD‐DFT studies assigned electronic transition that imbues deep...
Oxidative addition is an essential elementary reaction in organometallic chemistry and catalysis. While a diverse array of oxidative reactions has been reported to date, examples P-O bond activation are surprisingly rare. Herein, we report the ligand-templated phosphinite diphosphinito aniline compound HN(2-OPiPr2-3,5-tBu-C6H2)2 [H(P2ONO)] at Ni0 form (PONO)Ni(HPiPr2) after proton rearrangement. Notably, cleavage occurs selectively over amine N-H activation. Additionally, ligand...
Molybdenum complexes supported by tridentate pincer ligands are exceptional catalysts for dinitrogen fixation using chemical reductants, but little is known about their prospects electrochemical reduction of dinitrogen. The viability N2 binding and splitting a molybdenum(III) complex, (pyPNP)MoBr3 (pyPNP = 2,6-bis(tBu2PCH2)-C5H3N)), established in this work, providing foundation detailed mechanistic study electrode-driven formation the nitride complex (pyPNP)Mo(N)Br. Electrochemical kinetic...
The catalytic hydrogenation of carbon dioxide holds immense promise for applications in sustainable fuel synthesis and hydrogen storage. Mechanistic studies that connect thermodynamic parameters with the kinetics catalysis can provide new understanding guide predictive design improved catalysts. Reported here are thermochemical kinetic analyses a pincer-ligated rhenium complex (<sup>tBu</sup>POCOP)Re(CO)<sub>2</sub>(<sup>tBu</sup>POCOP =...
Proton-switchable access to seven-coordinate ONNO dicarboxamide and NNNN dicarboxamidate rhenium oxo complexes provides a platform for understanding thermodynamics bonding in pentagonal bipyramidal complexes.