Hadt, Ryan

Article from CaltechAUTHORS

Raj, Sumana L. and Curtolo, Felipe, el al. (2026) Ultrafast Population and Structural Dynamics of a Ni-Bipyridine Photoredox Catalyst Reveal a Significant Deactivation Pathway; Journal of Physical Chemistry Letters; Vol. 17; No. 4; 1164-1172; PMCID PMC12862818; 10.1021/acs.jpclett.5c03264
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Cusumano, Alexander Q. and Chaffin, Braden C., el al. (2025) Light-Promoted C(sp³)–C(sp³) Reductive Elimination from Dialkyl Niᴵᴵ Complexes; Journal of the American Chemical Society; Vol. 147; No. 36; 32941–32950; 10.1021/jacs.5c09925
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Kazmierczak, Nathanael and Xia, Kay, el al. (2025) A Spectrochemical Series for Electron Spin Relaxation; Journal of the American Chemical Society; Vol. 147; No. 3; 2849–2859; 10.1021/jacs.4c16571
Totoiu, Christian A. and Follmer, Alec H., el al. (2024) Probing Bioinorganic Electron Spin Decoherence Mechanisms with an Fe₂S₂ Metalloprotein; Journal of Physical Chemistry B; Vol. 128; No. 42; 10417–10426; 10.1021/acs.jpcb.4c06186
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Sutcliffe, Erica and Cagan, David A., el al. (2024) Ultrafast Photophysics of Ni(I)–Bipyridine Halide Complexes: Spanning the Marcus Normal and Inverted Regimes; Journal of the American Chemical Society; Vol. 146; No. 22; 15506-15514; PMCID PMC11157544; 10.1021/jacs.4c04091
Mirzoyan, Ruben and Follmer, Alec H., el al. (2024) Observing Long-Lived Photogenerated Holes in Cobalt Oxyhydroxide Oxygen Evolution Catalysts; ACS Applied Energy Materials; Vol. 7; No. 7; 2837-2846; 10.1021/acsaem.3c03269
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Bím, Daniel and Luedecke, Kaitlin M., el al. (2024) Light Activation and Photophysics of a Structurally Constrained Nickel(II)–Bipyridine Aryl Halide Complex; Inorganic Chemistry; Vol. 63; No. 9; 4120-4131; PMCID PMC11000520; 10.1021/acs.inorgchem.3c03822
Kazmierczak, Nathanael P. and Lopez, Nathan E., el al. (2024) Determining the key vibrations for spin relaxation in ruffled Cu(II) porphyrins via resonance Raman spectroscopy; Chemical Science; Vol. 15; No. 7; 2380-2390; PMCID PMC10866354; 10.1039/d3sc05774g
Kazmierczak, Nathanael P. and Luedecke, Kaitlin M., el al. (2023) T₁ Anisotropy Elucidates Spin Relaxation Mechanisms in an S = 1 Cr(IV) Optically Addressable Molecular Qubit; Journal of Physical Chemistry Letters; Vol. 14; No. 34; 7658-7664; 10.1021/acs.jpclett.3c01964
McNicholas, Brendon J. and Tong, Z. Jaron, el al. (2023) Electronic Structures of Nickel(II)-Bis(indanyloxazoline)-dihalide Catalysts: Understanding Ligand Field Contributions That Promote C(sp²)–C(sp³) Cross-Coupling; Inorganic Chemistry; Vol. 62; No. 34; 14010-14027; PMCID PMC10530056; 10.1021/acs.inorgchem.3c02048
Turro, Raymond F. and Wahlman, Julie L. H., el al. (2023) Mechanistic Investigation of Ni-Catalyzed Reductive Cross-Coupling of Alkenyl and Benzyl Electrophiles; Journal of the American Chemical Society; Vol. 145; No. 27; 14705-14715; PMCID PMC10347553; 10.1021/jacs.3c02649
Cagan, David A. and Bím, Daniel, el al. (2023) Photogenerated Ni(I)–Bipyridine Halide Complexes: Structure–Function Relationships for Competitive C(sp²)–Cl Oxidative Addition and Dimerization Reactivity Pathways; Inorganic Chemistry; Vol. 62; No. 24; 9538-9551; PMCID PMC10330939; 10.1021/acs.inorgchem.3c00917
McNicholas, Brendon J. and Nie, Cherish, el al. (2023) Boronated Cyanometallates; Inorganic Chemistry; Vol. 62; No. 7; 2959-2981; 10.1021/acs.inorgchem.2c03066
Follmer, Alec H. and Luedecke, Kaitlin M., el al. (2022) μ-Oxo Dimerization Effects on Ground- and Excited-State Properties of a Water-Soluble Iron Porphyrin CO₂ Reduction Catalyst; Inorganic Chemistry; Vol. 61; No. 50; 20493-20500; 10.1021/acs.inorgchem.2c03215
Kazmierczak, Nathanael P. and Hadt, Ryan G. (2022) Illuminating Ligand Field Contributions to Molecular Qubit Spin Relaxation via T₁ Anisotropy; Journal of the American Chemical Society; Vol. 144; No. 45; 20804-20814; 10.1021/jacs.2c08729
Cagan, David A. and Bím, Daniel, el al. (2022) Elucidating the Mechanism of Excited-State Bond Homolysis in Nickel–Bipyridine Photoredox Catalysts; Journal of the American Chemical Society; Vol. 144; No. 14; 6516-6531; PMCID PMC9979631; 10.1021/jacs.2c01356
Kazmierczak, Nathanael P. and Mirzoyan, Ruben, el al. (2021) The Impact of Ligand Field Symmetry on Molecular Qubit Coherence; Journal of the American Chemical Society; Vol. 143; No. 42; 17305-17315; 10.1021/jacs.1c04605
Jun Hwang, Seung and Hadt, Ryan G., el al. (2021) Photohalogen elimination chemistry in low-valent binuclear nickel complexes; Polyhedron; Vol. 203; Art. No. 115228; 10.1016/j.poly.2021.115228
Li, Nancy and Hadt, Ryan G., el al. (2021) Detection of high-valent iron species in alloyed oxidic cobaltates for catalysing the oxygen evolution reaction; Nature Communications; Vol. 12; Art. No. 4218; 10.1038/s41467-021-24453-6
Mirzoyan, Ruben and Kazmierczak, Nathanael P., el al. (2021) Deconvolving Contributions to Decoherence in Molecular Electron Spin Qubits: A Dynamic Ligand Field Approach; Chemistry: a European Journal; Vol. 27; No. 37; 9482-9494; 10.1002/chem.202100845
Gao, Yang and Hill, David E., el al. (2021) Electrochemical Nozaki–Hiyama–Kishi Coupling: Scope, Applications, and Mechanism; Journal of the American Chemical Society; Vol. 143; No. 25; 9478-9488; PMCID PMC8720499; 10.1021/jacs.1c03007
Reinhard, Marco E. and Mara, Michael W., el al. (2021) Short-lived metal-centered excited state initiates iron-methionine photodissociation in ferrous cytochrome c; Nature Communications; Vol. 12; Art. No. 1086; 10.1038/s41467-021-21423-w
Cagan, David A. and Stroscio, Gautam D., el al. (2020) Multireference Description of Nickel-Aryl Homolytic Bond Dissociation Processes in Photoredox Catalysis; Journal of Physical Chemistry A; Vol. 124; No. 48; 9915-9922; 10.1021/acs.jpca.0c08646
Ribson, Ryan D. and Choi, Gyeongshin, el al. (2020) Controlling Singlet Fission with Coordination Chemistry-Induced Assembly of Dipyridyl Pyrrole Bipentacenes; ACS Central Science; Vol. 6; No. 11; 2088-2096; PMCID PMC7706079; 10.1021/acscentsci.0c01044
Follmer, Alec H. and Ribson, Ryan D., el al. (2020) Understanding Covalent versus Spin–Orbit Coupling Contributions to Temperature-Dependent Electron Spin Relaxation in Cupric and Vanadyl Phthalocyanines; Journal of Physical Chemistry A; Vol. 124; No. 44; 9252-9260; 10.1021/acs.jpca.0c07860
Ngo, Danh X. and Del Ciello, Sarah A., el al. (2020) Electronic Structures, Spectroscopy, and Electrochemistry of [M(diimine)(CN-BR₃)₄]²⁻ (M = Fe, Ru; R = Ph, C₆F₅) Complexes; Inorganic Chemistry; Vol. 59; No. 14; 9594-9604; 10.1021/acs.inorgchem.0c00632
Li, Nancy and Keane, Thomas P., el al. (2020) Template-stabilized oxidic nickel oxygen evolution catalysts; Proceedings of the National Academy of Sciences of the United States of America; Vol. 117; No. 28; 16187-16192; PMCID PMC7368284; 10.1073/pnas.2001529117
Stroscio, Gautam D. and Srnec, Martin, el al. (2020) Multireference Ground and Excited State Electronic Structures of Free- versus Iron Porphyrin-Carbenes; Inorganic Chemistry; Vol. 59; No. 13; 8707-8715; 10.1021/acs.inorgchem.0c00249
Higdon, Nicholas J. and Barth, Alexandra T., el al. (2020) Spin-Phonon Coupling and Dynamic Zero-Field Splitting Contributions to Spin Conversion Processes in Iron(II) Complexes; Journal of Chemical Physics; Vol. 152; No. 20; Art. No. 204306; 10.1063/5.0006361
Mirzoyan, Ruben and Hadt, Ryan G. (2020) The Dynamic Ligand Field of a Molecular Qubit: Decoherence Through Spin–Phonon Coupling; Physical Chemistry Chemical Physics; Vol. 22; No. 20; 11249-11265; 10.1039/D0CP00852D
Jette, Carina I. and Tong, Z. Jaron, el al. (2020) Copper-Catalyzed Enantioselective Allylic Alkylation with a γ-Butyrolactone-Derived Silyl Ketene Acetal; Angewandte Chemie International Edition; Vol. 59; No. 5; 2033-2038; PMCID PMC7051182; 10.1002/anie.201912618
Stroscio, Gautam D. and Ribson, Ryan D., el al. (2019) Quantifying Entatic States in Photophysical Processes: Applications to Copper Photosensitizers; Inorganic Chemistry; Vol. 58; No. 24; 16800-16817; 10.1021/acs.inorgchem.9b02976
Snyder, Benjamin E. R. and Bols, Max L., el al. (2018) Mechanism of selective benzene hydroxylation catalyzed by iron-containing zeolites; Proceedings of the National Academy of Sciences of the United States of America; Vol. 115; No. 48; 12124-12129; PMCID PMC6275498; 10.1073/pnas.1813849115
Hong, Jiyun and Kelley, Matthew S., el al. (2018) The Nature of the Long-Lived Excited State in a Ni^(II) Phthalocyanine Complex Investigated by X-Ray Transient Absorption Spectroscopy; ChemSusChem; Vol. 11; No. 14; 2421-2428; 10.1002/cssc.201800777
Hayes, Dugan and Kohler, Lars, el al. (2018) Excited state electron and energy relays in supramolecular dinuclear complexes revealed by ultrafast optical and X-ray transient absorption spectroscopy; Chemical Science; Vol. 9; No. 4; 860-875; PMCID PMC5873173; 10.1039/C7SC04055E
Hadt, Ryan G. (2017) High-valent states in cobalt and nickel oxygen-evolving catalysts and their role in O—O bond formation; Acta Crystallographica. Section A, Foundations of Crystallography; Vol. 73; No. a1; Art. No. a152
Kohler, Lars and Hadt, Ryan G., el al. (2017) Synthesis, structure, and excited state kinetics of heteroleptic Cu(I) complexes with a new sterically demanding phenanthroline ligand; Dalton Transactions; Vol. 46; No. 38; 13088-13100; 10.1039/c7dt02476b
Kelley, Matthew S. and Shelby, Megan L., el al. (2017) Ultrafast dynamics of two copper bis-phenanthroline complexes measured by x-ray transient absorption spectroscopy; Journal of Physics B: Atomic, Molecular and Optical Physics; Vol. 50; No. 15; Art. No. 154006; 10.1088/1361-6455/aa7b97
Kjær, Kasper S. and Zhang, Wenkai, el al. (2017) Ligand manipulation of charge transfer excited state relaxation and spin crossover in [Fe(2,2'-bipyridine)_2(CN)_2]; Structural Dynamics; Vol. 4; No. 4; Art. No. 044030; PMCID PMC5461172; 10.1063/1.4985017
Mara, Michael W. and Hadt, Ryan G., el al. (2017) Metalloprotein entatic control of ligand-metal bonds quantified by ultrafast x-ray spectroscopy; Science; Vol. 356; No. 6344; 1276-1280; PMCID PMC5706643; 10.1126/science.aam6203
Brodsky, Casey N. and Hadt, Ryan G., el al. (2017) In situ characterization of cofacial Co(IV) centers in Co_4O_4 cubane: Modeling the high-valent active site in oxygen-evolving catalysts; Proceedings of the National Academy of Sciences of the United States of America; Vol. 114; No. 15; 3855-3860; PMCID PMC5393202; 10.1073/pnas.1701816114
Li, Nancy and Bediako, D. Kwabena, el al. (2017) Influence of iron doping on tetravalent nickel content in catalytic oxygen evolving films; Proceedings of the National Academy of Sciences of the United States of America; Vol. 114; No. 7; 1486-1491; PMCID PMC5321006; 10.1073/pnas.1620787114
Zhang, Wenkai and Kjær, Kasper S., el al. (2017) Manipulating charge transfer excited state relaxation and spin crossover in iron coordination complexes with ligand substitution; Chemical Science; Vol. 8; No. 1; 515-523; PMCID PMC5341207; 10.1039/c6sc03070j
Hayes, Dugan and Hadt, Ryan G., el al. (2016) Electronic and nuclear contributions to time-resolved optical and X-ray absorption spectra of hematite and insights into photoelectrochemical performance; Energy and Environmental Science; Vol. 2016; No. 12; 3754-3769; 10.1039/C6EE02266A
Solomon, Edward I. and Hadt, Ryan G., el al. (2016) Activating Metal Sites for Biological Electron Transfer; Israel Journal of Chemistry; Vol. 56; No. 9-10; 649-659; PMCID PMC5517049; 10.1002/ijch.201600016
Hadt, Ryan G. and Hayes, Dugan, el al. (2016) X-ray Spectroscopic Characterization of Co(IV) and Metal-Metal Interactions in Co_4O_4: Electronic Structure Contributions to the Formation of High-Valent States Relevant to the Oxygen Evolution Reaction; Journal of the American Chemical Society; Vol. 138; No. 34; 11017-11030; 10.1021/jacs.6b04663
Li, Lianwei and Hadt, Ryan G., el al. (2016) Photocatalysts Based on Cobalt-Chelating Conjugated Polymers for Hydrogen Evolution from Water; Chemistry of Materials; Vol. 28; No. 15; 5394-5399; 10.1021/acs.chemmater.6b01477
Hwang, Seung Jun and Anderson, Bryce L., el al. (2015) Halogen Photoelimination from Monomeric Nickel(III) Complexes Enabled by the Secondary Coordination Sphere; Organometallics; Vol. 34; No. 19; 4766-4774; 10.1021/acs.organomet.5b00568
Hwang, Seung Jun and Powers, David C., el al. (2015) Trap-Free Halogen Photoelimination from Mononuclear Ni(III) Complexes; Journal of the American Chemical Society; Vol. 137; No. 20; 6472-6475; 10.1021/jacs.5b03192
Vanelderen, Pieter and Snyder, Benjamin E. R., el al. (2015) Spectroscopic definition of the copper active sites in mordenite: selective methane oxidation; Journal of the American Chemical Society; Vol. 137; No. 19; 6383-6392; 10.1021/jacs.5b02817
Kroll, Thomas and Hadt, Ryan G., el al. (2014) Resonant inelastic X-ray scattering on ferrous and ferric bis-imidazole porphyrin and cytochrome c: nature and role of the axial methionine-Fe bond; Journal of the American Chemical Society; Vol. 136; No. 52; 18087-18099; PMCID PMC4291809; 10.1021/ja5100367
Hadt, Ryan G. and Gorelsky, Serge I., el al. (2014) Anisotropic covalency contributions to superexchange pathways in type one copper active sites; Journal of the American Chemical Society; Vol. 136; No. 42; 15034-15045; PMCID PMC4210080; 10.1021/ja508361h
Nguyen, Andy I. and Hadt, Ryan G., el al. (2014) Efficient C-H Bond Activations O_2 Cleavage by a Dianionic Cobalt(II) Complex; Chemical Science; Vol. 5; No. 7; 2874-2878; PMCID PMC4111274; 10.1039/C4SC00108G
Zhang, Wenkai and Alonso-Mori, Roberto, el al. (2014) Tracking excited-state charge and spin dynamics in iron coordination complexes; Nature; Vol. 509; No. 7500; 345-348; PMCID PMC5668134; 10.1038/nature13252
Solomon, Edward I. and Heppner, David E., el al. (2014) Copper active sites in biology; Chemical Reviews; Vol. 114; No. 7; 3659-3853; PMCID PMC4040215; 10.1021/cr400327t
Tsai, Ming-Li and Hadt, Ryan G., el al. (2014) [Cu_2O]^(2+) active site formation in Cu-ZSM-5: geometric and electronic structure requirements for N_2O activation; Journal of the American Chemical Society; Vol. 136; No. 9; 3522-3529; 10.1021/ja4113808
Sieracki, Nathan A. and Tian, Shiliang, el al. (2014) Copper-sulfenate complex from oxidation of a cavity mutant of Pseudomonas aeruginosa azurin; Proceedings of the National Academy of Sciences of the United States of America; Vol. 111; No. 3; 924-929; PMCID PMC3903256; 10.1073/pnas.1316483111
Vanelderen, Pieter and Vancauwenbergh, Julie, el al. (2014) Spectroscopy and redox chemistry of copper in mordenite; ChemPhysChem; Vol. 15; No. 1; 91-99; 10.1002/cphc.201300730
Tsai, Ming-Li and Hadt, Ryan G., el al. (2013) Axial interactions in the mixed-valent Cu_A active site and role of the axial methionine in electron transfer; Proceedings of the National Academy of Sciences of the United States of America; Vol. 110; No. 36; 14658-14663; PMCID PMC3767567; 10.1073/pnas.1314242110
Hadt, Ryan G. and Sun, Ning, el al. (2012) Spectroscopic and DFT studies of second-sphere variants of the type 1 copper site in azurin: covalent and nonlocal electrostatic contributions to reduction potentials; Journal of the American Chemical Society; Vol. 134; No. 40; 16701-16716; PMCID PMC3506006; 10.1021/ja306438n
Hadt, Ryan G. and Xie, Xiangjin, el al. (2012) Analysis of resonance Raman data on the blue copper site in pseudoazurin: excited state π and σ charge transfer distortions and their relation to ground state reorganization energy; Journal of Inorganic Biochemistry; Vol. 115; 155-162; 10.1016/j.jinorgbio.2012.03.006
Durand, Fabien and Kjaergaard, Christian Hauge, el al. (2012) Bilirubin oxidase from Bacillus pumilus: a promising enzyme for the elaboration of efficient cathodes in biofuel cells; Biosensors & Bioelectronics; Vol. 35; No. 1; 140-146; PMCID PMC3724473; 10.1016/j.bios.2012.02.033
Vanelderen, Pieter and Hadt, Ryan G., el al. (2011) Cu-ZSM-5: A biomimetic inorganic model for methane oxidation; Journal of Catalysis; Vol. 284; No. 2; 157-164; PMCID PMC3593946; 10.1016/j.jcat.2011.10.009
Nemykin, Victor N. and Hadt, Ryan G. (2010) Interpretation of the UV-vis spectra of the meso(ferrocenyl)-containing porphyrins using a TDDFT approach: is Gouterman's classic four-orbital model still in play?; Journal of Physical Chemistry A; Vol. 114; No. 45; 12062-12066; 10.1021/jp1083828
Smeets, Pieter J. and Hadt, Ryan G., el al. (2010) Oxygen precursor to the reactive intermediate in methanol synthesis by Cu-ZSM-5; Journal of the American Chemical Society; Vol. 132; No. 42; 14736-14738; PMCID PMC2974621; 10.1021/ja106283u
Nemykin, Victor N. and Rohde, Gregory T., el al. (2010) Long-range electronic communication in free-base meso-poly(ferrocenyl)-containing porphyrins; Inorganic Chemistry; Vol. 49; No. 16; 7497-7509; 10.1021/ic101012a
Hadt, Ryan G. and Nemykin, Victor N., el al. (2009) Comparative calculation of EPR spectral parameters in [Mo^VOX_4]^-, [Mo^VOX_5]^(2-), and [Mo^VOX_4(H_2O)]^- complexes; Physical Chemistry Chemical Physics; Vol. 11; No. 44; 10377-10384; PMCID PMC2879133; 10.1039/b905554a
Nemykin, Victor N. and Rohde, Gregory T., el al. (2009) Electron-transfer processes in metal-free tetraferrocenylporphyrin. Understanding internal interactions to access mixed-valence States potentially useful for quantum cellular automata; Journal of the American Chemical Society; Vol. 131; No. 41; 14969-14978; 10.1021/ja905310h
Xie, Xiangjin and Hadt, Ryan G., el al. (2009) A variable temperature spectroscopic study on Paracoccus pantotrophus pseudoazurin: protein constraints on the blue Cu site; Journal of Inorganic Biochemistry; Vol. 103; No. 10; 1307-1313; 10.1016/j.jinorgbio.2009.04.012
Hadt, Ryan G. and Nemykin, Victor N. (2009) Exploring the ground and excited state potential energy landscapes of the mixed-valence biferrocenium complex; Inorganic Chemistry; Vol. 48; No. 9; 3982-3992; 10.1021/ic801801m
Nemykin, Victor N. and Galloni, Pierluca, el al. (2008) Metal-free and transition-metal tetraferrocenylporphyrins part 1: synthesis, characterization, electronic structure, and conformational flexibility of neutral compounds; Dalton Transactions; Vol. 2008; No. 32; 4233-4246; 10.1039/b805156a
Nemykin, Victor N. and Hadt, Ryan G., el al. (2007) Influence of molecular geometry, exchange-correlation functional, and solvent effects in the modeling of vertical excitation energies in phthalocyanines using time-dependent density functional theory (TDDFT) and polarized continuum model TDDFT methods: can modern computational chemistry methods explain experimental controversies?; Journal of Physical Chemistry A; Vol. 111; No. 50; 12901-12913; 10.1021/jp0759731
Nemykin, Victor N. and Makarova, Elena A., el al. (2007) Preparation, characterization, molecular and electronic structures, TDDFT, and TDDFT/PCM study of the solvatochromism in cyanovinylferrocenes; Inorganic Chemistry; Vol. 46; No. 23; 9591-9601; 10.1021/ic700558v
Nemykin, Victor N. and Barrett, Christopher D., el al. (2007) Mixed-valence states formation in conformationally flexible metal-free 5,10,15,20-tetraferrocenylporphyrin and 5,10-bisferrocenyl-15,20-bisphenylporphyrin; Dalton Transactions; Vol. 2007; No. 31; 3378-3389; 10.1039/b703581k
Nemykin, Victor N. and Hadt, Ryan G. (2006) Influence of Hartree-Fock exchange on the calculated Mössbauer isomer shifts and quadrupole splittings in ferrocene derivatives using density functional theory; Inorganic Chemistry; Vol. 45; No. 20; 8297-8307; 10.1021/ic061176q