Professor Michael B. Hall is Davidson Professor of Science and Founding Director of the Laboratory for Molecular Simulation
Professor Hall is a leading authority in computational chemistry and the application of computer technology to problems that range from materials science to protein folding. Professor Hall’s research career is reflected in over 400 peer-reviewed publications in major journals, continuous research grants from both the National Science Foundation and The Welch Foundation for over 45 years, and training 35 postdoctoral associates and 38 graduate students. Professor Hall was born and raised in Pennsylvania and obtained his B. S. degree in Chemistry from Juniata College. Following his Ph. D. work with Richard Fenske at the University of Wisconsin, Madison, he was awarded an AEI postdoctoral fellowship in theoretical chemistry at the University of Manchester, England, where he studied with Ian Hillier. At Texas A&M University
EDUCATION
FORMAL EDUCATION
University of Wisconsin, Madison, WI, Physical Chemistry, Ph.D. 1971
Juniata College, Huntingdon, PA, Chemistry, B.S. 1966
POSTDOCTORAL STUDIES
University of Wisconsin, Madison, Research Associate 1973-1974
University of Manchester, England, AEI Fellowship 1971-1972
RESEARCH, TEACHING, or OTHER INTERESTS
Inorganic Chemistry, Physical and Theoretical Chemistry, Catalysis, Computer Science Applications
Structural and Electronic Complexities of a Sulfur-Bridged Di-Iron Complex Composed of Mono- and Di-Nitrosyl Units Sarnali Sanfui, Manuel Quiroz, Jialu Li, Yang Ha, Feipeng Yang, Jinghua Guo, Nattamai Bhuvanesh, Brad S. Pierce, Perla B. Balbuena, Paul A. Lindahl, Michael B. Hall, Marcetta Y. Darensbourg Advanced Science, 2026 The delocalized, thermodynamically stable cation, [(N 2 S 2 )Fe(NO)•Fe(NO) 2 ] + , an adduct of mono‐nitrosyl and dinitrosyl iron units, is analyzed to address the unusual stability of the sulfur‐bridged diiron complex in its three overall redox levels, +, 0, and −. X‐ray diffraction and myriad spectroscopic techniques probe products of sequential electron uptake in the corresponding neutral and anionic species. Conundrums include unified blueshifts of the overall 3‐band, ν(NO), pattern with added electrons. One‐electron reduction changes the anti‐ferromagnetically coupled, S = 0, cationic diiron species to the neutral analog, S = ½, with unpaired spin mainly localized on the MNIU, which decreases its ∠Fe–N–O angle by 10 degrees in response to the extra electron density. Subsequent reduction to the anionic species, S = 1, involves a major geometric change at the MNIU, which moves the Fe in {Fe(NO)} 8 out of the N 2 S 2 plane. Site‐specific 15 N labeling of nitrosyl in the MNIU confirms the IR analysis and shows rapid NO exchange between the MNIU/DNIU (mono‐nitrosyl iron unit/dinitrosyl iron unit) pairs during its synthesis at RT. Mössbauer spectroscopy, S K‐edge XAS, and molecular orbital calculations confirm the ability of NO and the versatility of sulfur bridges to buffer and distribute electrons, a key to their major importance in metalloenzymes.
Enantiopure Phosphine Oxides with Electron-Rich Chiral Rhenium Stereocenters: Syntheses, Structures, and Brønsted Basicities Sandra Eichenseher, Florian Friedlein, Michael J. O’Brien, Michael B. Hall, Frank Hampel, John A. Gladysz European Journal of Inorganic Chemistry, 2025 The chiral racemic methyl complex (η5‐C5R5)Re(NO)(PPh3)(CH3) (2) is converted to the rhenium‐containing phosphorus donor ligands (η5‐C5R5)Re(NO)(PPh3)((CH2)nPR'2) (n/R/R’ = a, 0/H/Ph; 4b, 0/H/t‐Bu; 7a, 0/Me/Ph; 10a, 1/H/Ph; 10b, 1/H/t‐Bu) via standard sequences involving intermediate phosphonium salts (4a,b and 7a; TfOH/CH2Cl2 or HBF4/chlorobenzene, then PR2H, then t‐BuOK; 10a,b, Ph3C+ X−, then PR2H, then t‐BuOK). These are converted to the title phosphine oxides (η5‐C5R5)Re(NO)(PPh3)((CH2)nP(O)R'2) (n/R/R’ = 1a, 0/H/Ph; 1b, 0/H/t‐Bu; 8a, 0/Me/Ph; 11a, 1/H/Ph; 11b, 1/H/t‐Bu) using PhIO, Me3SiOOSiMe3 or (for 8a) air. The enantiopure methyl complex (S)‐2 is similarly converted to (R)‐4a,b, (R)‐8a, and (S)‐11a,b. The crystal structures of 1a, (S)‐1a·(H2O)0.5, (S)‐8a, and 11a·CHCl3 are determined. The basicities of PO‐containing species play key roles in certain enantioselective catalytic reactions. Those of the title and related compounds are computed by DFT (i.a. 8b > 8a > 1b > 1a > 11b > 11a > t‐Bu3PO > Ph3PO). The enhancements in the rhenium‐containing species are rationalized.
How Geometric Constraints Control the Hydride Position and Activity in [NiFe]-Hydrogenases and Their Biomimetic Complexes Shuqiang Niu, Michael B. Hall Inorganic Chemistry, 2025 High Resolution Image Download MS PowerPoint Slide The Ni-R active site in [NiFe]-hydrogenase features a bridging hydride between the Ni and Fe, displaced toward the Ni. However, all synthetic Ni-R models reported to date exhibit a hydride displaced toward Fe and display low turnover frequencies for H 2 evolution. Understanding the factors governing the hydride position and activity of Ni-R and biomimetic complexes is crucial for developing efficient hydrogen-evolving catalysts. By utilizing the CCSD theory, DFT, NBO, and QTAIM analysis, we investigated these factors in a Ni-R active-site model ( 1 ), and two representative biomimetic complexes, 2* and 3 . Our results reveal that the Ni site of 1 inherently prefers a square-planar [S 2 NiSH] configuration with an apically positioned thiolate and that hydride positioning is governed by the strength of [Ni–H–Fe] three-center two-electron bonding, which is modulated by the geometric torsion between the Ni terminal ligands and the bridging thiolates. By modifying the linkers between the Ni terminal ligands and bridging thiolate ligands of 2* and 3, we designed virtual biomimetic complexes ( 4–10 ). These complexes exhibit improved hydride nucleophilicity and increased potential for H 2 formation, providing valuable insights into how geometric and electronic factors influence hydride activity and informing the design of more effective biomimetic hydrogenase models.
Origin of Intramolecular versus Intermolecular C-H Arene Activation Selectivity by Cyclopentadienyl-Triphenylphosphine Iridium Bowen Zhang, Daniel H. Ess, Michael B. Hall Inorganic Chemistry, 2025 Photolysis of (η 5 -C 5 Me 5 )Ir(PPh 3 )(H) 2 in benzene generates the 16-electron (16e – ) complex (η 5 -C 5 Me 5 )Ir(PPh 3 ) that undergoes competitive intra molecular ortho-metalation with a phenyl group from −PPh 3 and inter molecular C–H activation with benzene. Previous density functional theory (DFT) studies identified the intra molecular π-complex and the inter molecular benzene π-complex intermediates and their corresponding C–H activation transition states. However, neither the mechanism of interconversion between these intermediates nor the origin of intra molecular versus inter molecular pathway selectivity has been established. Here, we characterized the open-shell 16e – iridium species and extensively mapped out the energy landscape for intra molecular ortho-metalation of −PPh 3 versus inter molecular benzene C–H activation. Also, we performed DFT-based direct dynamics simulations, and the results suggest that the intra molecular versus inter molecular pathway selectivity is determined dynamically within picoseconds as the 16e – iridium species evolves into a coordinatively saturated structure. During this process, the π-complexes are formed concurrently with, instead of prior to, the iridium hydrides, which could not be explained by kinetic models that assume C–H cleavage as the rate-limiting step. These findings demonstrate that dynamics simulations in addition to DFT calculations are needed for a more complete mechanistic understanding of photoinduced C–H activation reactions, of which the product selectivity can be influenced by atomic motion.
Reactivity of Methyl Diruthenium Complexes with the Bis(diphenylphosphino)methane (dppm) Ligand and Formation of Dinitrogen and Dihydrogen Complexes via Methane Loss Suhashini Handunneththige, Ryder Downey, Michael B. Hall, William W. Brennessel, Robert M. Chin Organometallics, 2025 A diruthenium complex with a μ-CH 3 ligand, [ cis- {(η 5 -C 5 H 2 ( t -Bu)) 2 (CMe 2 ) 2 }Ru 2 (dppm) 2 (μ-CH 3 )][B(Ar F ) 4 ] (dppm = 1,1-bis(diphenylphosphino)methane) has been synthesized, structured, and its reactivity explored. Reaction of the μ-CH 3 complex with H 2 led to a fluxional dihydrogen/hydrido complex with the hydrogens exchanging between the two ruthenium centers, results consistent with the NMR spectroscopy, the crystal structure, and density functional theory. The activation barrier for this exchange was calculated to be ∼12 kcal/mol. The μ-1,2-N 2 complex formed when the μ-CH 3 diruthenium or dimethyl diruthenium complexes were treated with acid, and the crystal structure showed a Ru–N–N–Ru geometry with a smaller Ru–N–N angle than other related complexes. The stability of a methane diruthenium complex with either a dppm or dmpm (1,1-bis(dimethylphosphino)methane) ligand has also been computationally investigated, with the less sterically demanding dmpm forming a more stable methane complex than that with the dppm ligand.
A sulfur-templated Ni-Ni′ coordination polymer that relies on a polarizable nickel nitrosyl hub Manish Jana, Michael B. Hall, Marcetta Y. Darensbourg Dalton Transactions, 2024 The templating properties of a diazanickel-cis-dithiolate towards triphenylphosphinegold (d10-Au+) inspired the synthesis of {Ni-(NO)}10 as a redox-active and structurally mobile S-based adduct which was then condensed with into a coordination polymer.
A Caged Neutral 17-Valence-Electron Iron(I) Radical [Fe(CO)2(Cl)(P((CH2)10)3P)]•: Synthetic, Structural, Spectroscopic, Redox, and Computational Studies Samuel R. Zarcone, Zihan Zhang, Suhashini Handunneththige, Zhen Ni, Nattamai Bhuvanesh, Michael Nippe, Karsten Meyer, Michael B. Hall, John A. Gladysz Inorganic Chemistry, 2024 UV irradiation of yellow CH2Cl2 solutions of trans-Fe(CO)3(P((CH2)10)3P) (2a) and PMe3 (10 equiv) gives, in addition to the previously reported dibridgehead diphosphine P((CH2)10)3P (46%), a green paramagnetic complex that crystallography shows to be the trigonal-bipyramidal iron(I) radical trans-[Fe(CO)2(Cl)(P((CH2)10)3P)]• (1a•; 31% after workup). This is a rare example of an isolable species of the formula [Fe(CO)4–n(L)n(X)]• (n = 0–3, L = two-electron-donor ligand; X = one-electron-donor ligand). Analogous precursors with longer P(CH2)nP segments (n = 12, 14, 16, 18) give only the demetalated diphosphines, and a rationale is proposed. The magnetic susceptibility of 1a•, assayed by Evans’ method and SQUID measurements, indicates a spin (S) of 1/2. Cyclic voltammetry shows that 1a• undergoes a partially reversible one-electron oxidation, but no facile reduction. The UV–visible, EPR, and 57Fe Mössbauer spectra are analyzed in detail. Complex 2a is similarly studied, and, despite the extra valence electron, exhibits a comparable oxidation potential (ΔE1/2 ≤ 0.04 V). The crystal structure shows a cage conformation, solvation level, disorder motif, and unit cell parameters essentially identical to those of 1a•. DFT calculations provide much insight regarding the structural, redox, and spectroscopic properties.
Metathesis and Metallacycle Reactivity of d10 Ni Perfluorocarbenes with Alkenes Alex L. Daniels, Behnaz Ghaffari, Deqing Kong, Jia Guan, Michael B. Hall, R. Tom Baker Organometallics, 2024 We showed previously that the d 10 nickel perfluorocarbene complex, P 3 Ni═CF(CF 3 ) [P = P(O i Pr) 3 ], 1, reacts with fluoroalkenes to produce both 4-membered nickelacycles and metathesis products via separate reaction pathways. Herein, we compare the reactivity of 1 with a variety of alkenes. The reaction of 1 with hexafluoropropene [CF 2 ═CF(CF 3 ), HFP] affords a single metallacycle, taking advantage of the diradical mechanism in which the carbene carbon adds to the CF 2 end of HFP. In contrast, 1 and perfluoro(methyl vinyl ether), CF 2 ═CF(OCF 3 ), yield both metallacycle and metathesis products, with preferential formation of the more stabilized difluorocarbene [P 3 Ni═CF 2 vs P 3 Ni═CF(OCF 3 )] and a higher ratio of metathesis to metallacycle products than using tetrafluoroethylene or vinylidene difluoride. Attempts to form fluoropolymers via ring-opening metathesis polymerization of perfluorocyclobutene and hexafluorocyclopentene briefly gave new nickel carbenes but then yielded Ni fluoroalkene complexes with the loss of the CF(CF 3 ) unit. Surprisingly, both ethylene and styrene derivatives gave only metallacycles, although evidence was obtained for alkene coordination to nickel; computational studies are presented to identify the origin of these observations. Finally, insertion of ethylene into the ethylene-derived nickelacyclobutane afforded a new fluorinated alkene, CH 2 ═CHCH 2 CH 2 CHFCF 3, formed presumably via nickelacyclohexane through selective β-H and reductive eliminations.
Redox active iron nitrosyl units in proton reduction electrocatalysis Chung-Hung Hsieh, Shengda Ding, Özlen F. Erdem, Danielle J. Crouthers, Tianbiao Liu, Charles C. L. McCrory, Wolfgang Lubitz, Codrina V. Popescu, Joseph H. Reibenspies, Michael B. Hall, Marcetta Y. Darensbourg Nature Communications, 2014
The Activation of Dihydrogen Jesse W. Tye, Marcetta Y. Darensbourg, Michael B. Hall Activation of Small Molecules Organometallic and Bioinorganic Perspectives, 2006
Laplacian of the electronic charge distribution in transition metal complexes: a progress report Transactions of the American Crystallographic Association, 1990
Iron Tris (phosphine)-Borane,-Carbon, and-Silane Complexes in Catalytic N2 Reduction S Yu, MB Hall Journal of Organometallic Chemistry, 124101 , 2026 2026
Mechanism of Dinitrogen Reduction in a Borylene Complex by Density Functional Theory S Yu, MB Hall Inorganic Chemistry , 2026 2026
Structural and Electronic Complexities of a Sulfur‐Bridged Di‐Iron Complex Composed of Mono‐and Di‐Nitrosyl Units S Sanfui, M Quiroz, J Li, Y Ha, F Yang, J Guo, N Bhuvanesh, BS Pierce, ... Advanced Science 13 (1), e13976 , 2026 2026
Enantiopure Phosphine Oxides with Electron‐Rich Chiral Rhenium Stereocenters: Syntheses, Structures, and Brønsted Basicities S Eichenseher, F Friedlein, MJ O’Brien, MB Hall, F Hampel, JA Gladysz European Journal of Inorganic Chemistry 28 (27), e202500260 , 2025 2025
Dimetalloylene (M-E-M) Complexes of Heavier Main Group Elements Ge, Sn, Pb, Bi via Cleavage of E-X Bonds (X = N(SiMe 3 ) 2 , O t Bu) with an Iridium Hydride (vol … TG Saint-Denis, B Zhang, NS Settineri, RC Handford, MB Hall, TD Tilley CHEMISTRY-A EUROPEAN JOURNAL 31 (49) , 2025 2025
How Geometric Constraints Control the Hydride Position and Activity in [NiFe]-Hydrogenases and Their Biomimetic Complexes S Niu, MB Hall Inorganic Chemistry 64 (20), 10078-10086 , 2025 2025 Citations: 2
Origin of Intramolecular versus Intermolecular C–H Arene Activation Selectivity by Cyclopentadienyl–Triphenylphosphine Iridium B Zhang, DH Ess, MB Hall Inorganic Chemistry 64 (16), 8152-8163 , 2025 2025 Citations: 2
Reactivity of Methyl Diruthenium Complexes with the Bis (diphenylphosphino) methane (dppm) Ligand and Formation of Dinitrogen and Dihydrogen Complexes via Methane Loss S Handunneththige, R Downey, MB Hall, WW Brennessel, RM Chin Organometallics 44 (4), 568-581 , 2025 2025 Citations: 1
A sulfur-templated Ni–Ni′ coordination polymer that relies on a polarizable nickel nitrosyl hub M Jana, MB Hall, MY Darensbourg Dalton Transactions 54 (12), 4927-4934 , 2025 2025 Citations: 1
A Caged Neutral 17-Valence-Electron Iron(I) Radical [Fe(CO) 2 (Cl)(P((CH 2 ) 10 ) 3 P)] • : Synthetic, Structural, Spectroscopic, Redox, and Computational Studies SR Zarcone, Z Zhang, S Handunneththige, Z Ni, N Bhuvanesh, M Nippe, ... Inorganic Chemistry 63 (35), 16313-16326 , 2024 2024 Citations: 2
Metathesis and Metallacycle Reactivity of d 10 Ni Perfluorocarbenes with Alkenes AL Daniels, B Ghaffari, D Kong, J Guan, MB Hall, RT Baker Organometallics 43 (11), 1213-1221 , 2024 2024 Citations: 2
Theoretical Investigation of Linear Relationships between the Dihedral Torsion Angles and Diosmium Bond Distances in Diosmium Sawhorse Complexes Y Tong, CB Powell, GL Powell, MB Hall Inorganic Chemistry 63 (4), 1898-1908 , 2024 2024 Citations: 2
Site specific redox properties in ligand differentiated di-nickel complexes inspired by the acetyl CoA synthase active site M Quiroz, M Jana, K Liu, N Bhuvanesh, MB Hall, MY Darensbourg Dalton Transactions 53 (17), 7414-7423 , 2024 2024 Citations: 1
Cooperative redox and spin activity from three redox congeners of sulfur-bridged iron nitrosyl and nickel dithiolene complexes (vol 119, e2201240119, 2022) M Quiroz, MM Lockart, MR Saber, SW Vali, LC Elrod, BS Pierce, MB Hall, ... PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF … , 2023 2023
QM evaluation of the intramolecular aromatic π-π interactions of Ir (I) complex transition states Y Liu, AA Gallo, Y Liu, MB Hall, BR Johnson Journal of Molecular Structure 1291, 135907 , 2023 2023 Citations: 5
Sulfur Lone Pairs Control Topology in Heterotrimetallic Complexes: An Experimental and Theoretical Study P Guerrero-Almaraz, M Quiroz, DR Rodriguez, M Jana, MB Hall, ... ACS Organic & Inorganic Au 3 (6), 393-402 , 2023 2023 Citations: 3
Dimetalloylene (M‐E‐M) Complexes of Heavier Main Group Elements Ge, Sn, Pb, Bi via Cleavage of E‐X Bonds (X=N(SiMe 3 ) 2 , O t Bu) with an Iridium Hydride TG Saint‐Denis, B Zhang, NS Settineri, RC Handford, MB Hall, TD Tilley Chemistry–A European Journal 29 (49), e202301863 , 2023 2023 Citations: 5
Protein engineering of NADH pyrophosphatase for efficient biocatalytic production of reduced nicotinamide mononucleotide Y Liu, JS Gong, G Marshall, C Su, M Hall, H Li, GQ Xu, JS Shi, ZH Xu Frontiers in Bioengineering and Biotechnology 11, 1159965 , 2023 2023 Citations: 3
Improving a Methane C–H Activation Complex by Metal and Ligand Alterations from Computational Results DB Ninkovic, S Moncho, P Petrovic, MB Hall, SD Zaric, EN Brothers Inorganic Chemistry 62 (13), 5058-5066 , 2023 2023 Citations: 3
Basis sets for transition metals: Optimized outer p functions M Couty, MB Hall Journal of computational chemistry 17 (11), 1359-1370 , 1996 1996 Citations: 528
Computational studies of [NiFe] and [FeFe] hydrogenases PEM Siegbahn, JW Tye, MB Hall Chemical reviews 107 (10), 4414-4435 , 2007 2007 Citations: 491
A capable bridging ligand for Fe-only hydrogenase: density functional calculations of a low-energy route for heterolytic cleavage and formation of dihydrogen HJ Fan, MB Hall Journal of the American Chemical Society 123 (16), 3828-3829 , 2001 2001 Citations: 418
Rhodium boryl complexes in the catalytic, terminal functionalization of alkanes JF Hartwig, KS Cook, M Hapke, CD Incarvito, Y Fan, CE Webster, MB Hall Journal of the American Chemical Society 127 (8), 2538-2552 , 2005 2005 Citations: 390
Flexible zirconium metal‐organic frameworks as bioinspired switchable catalysts S Yuan, L Zou, H Li, YP Chen, J Qin, Q Zhang, W Lu, MB Hall, HC Zhou Angewandte Chemie 128 (36), 10934-10938 , 2016 2016 Citations: 270
Theoretical Characterization of the Reaction Intermediates in a Model of the Nickel−Iron Hydrogenase of Desulfovibrio gigas S Niu, LM Thomson, MB Hall Journal of the American Chemical Society 121 (16), 4000-4007 , 1999 1999 Citations: 239
Modeling the active sites in metalloenzymes. 3. Density functional calculations on models for [Fe]-hydrogenase: Structures and vibrational frequencies of the observed redox … Z Cao, MB Hall Journal of the American Chemical Society 123 (16), 3734-3742 , 2001 2001 Citations: 231
Electron distributions and the chemical bond P Coppens, MB Hall Springer Science & Business Media , 2012 2012 Citations: 221
Thermally stable homogeneous catalysts for alkane dehydrogenation MW Haenel, S Oevers, K Angermund, WC Kaska, HJ Fan, MB Hall Angewandte Chemie International Edition 40 (19), 3596-3600 , 2001 2001 Citations: 220
Fundamental properties of small molecule models of Fe-only hydrogenase: computations relative to the definition of an entatic state in the active site IP Georgakaki, LM Thomson, EJ Lyon, MB Hall, MY Darensbourg Coordination chemistry reviews 238, 255-266 , 2003 2003 Citations: 211
Experimental and computational evidence for a boron-assisted, σ-bond metathesis pathway for alkane borylation CE Webster, Y Fan, MB Hall, D Kunz, JF Hartwig Journal of the American Chemical Society 125 (4), 858-859 , 2003 2003 Citations: 206
Monomeric and oligomeric amine− borane σ-complexes of rhodium. Intermediates in the catalytic dehydrogenation of amine− boranes TM Douglas, AB Chaplin, AS Weller, X Yang, MB Hall Journal of the American Chemical Society 131 (42), 15440-15456 , 2009 2009 Citations: 198
De Novo design of synthetic di-iron (I) complexes as structural models of the reduced form of iron− iron hydrogenase JW Tye, MY Darensbourg, MB Hall Inorganic Chemistry 45 (4), 1552-1559 , 2006 2006 Citations: 192
Electronic effects steer the mechanism of asymmetric hydrogenations of unfunctionalized aryl-substituted alkenes Y Fan, X Cui, K Burgess, MB Hall Journal of the American Chemical Society 126 (51), 16688-16689 , 2004 2004 Citations: 188
Theoretical comparison between nucleophilic and electrophilic transition metal carbenes using generalized molecular orbital and configuration interaction methods TE Taylor, MB Hall Journal of the American Chemical Society 106 (6), 1576-1584 , 1984 1984 Citations: 186
Monoiron Hydrogenase Catalysis: Hydrogen Activation with the Formation of a Dihydrogen, Fe−H δ− ···H δ+ −O, Bond and Methenyl-H 4 MPT + Triggered Hydride … X Yang, MB Hall Journal of the American Chemical Society 131 (31), 10901-10908 , 2009 2009 Citations: 180
Dual electron uptake by simultaneous iron and ligand reduction in an N-heterocyclic carbene substituted [FeFe] hydrogenase model compound JW Tye, J Lee, HW Wang, R Mejia-Rodriguez, JH Reibenspies, MB Hall, ... Inorganic chemistry 44 (16), 5550-5552 , 2005 2005 Citations: 172
The catalytic dehydrogenation of ammonia-borane involving an unexpected hydrogen transfer to ligated carbene and subsequent carbon− hydrogen activation X Yang, MB Hall Journal of the American Chemical Society 130 (6), 1798-1799 , 2008 2008 Citations: 160
