About

Claudia Turro is the Chair and Dr. Melvin L. Morris Professor in the Department of Chemistry and Biochemistry at The Ohio State University. She received her B.S. with Honors in 1987 from Michigan State University, where she worked with Daniel G. Nocera and George E. Leroi, and earned her Ph.D. in 1992. She conducted postdoctoral work at Columbia University with Nicholas J. Turro from 1992 to 1995 under a Jane Coffin Childs Memorial Fund for Medical Research Postdoctoral Fellowship. She has been a faculty member at Ohio State since 1996. Her research focuses on inorganic photochemistry, excited state processes, solar energy conversion, and photochemotherapy, particularly understanding and utilizing reactions of metal complexes initiated with light. Her group investigates the control and dynamics of excited states, including photophysical properties and reactivity such as energy transfer, charge separation, and photochemical reactions, with applications in cancer treatment, sensing, and renewable energy. Professor Turro has received numerous awards, including the NSF Early CAREER Award, the Arnold and Mabel Beckman Foundation Young Investigator Award, and was elected a Fellow of the American Chemical Society and the American Association for the Advancement of Science. In 2024, she was elected a Member of the American Academy of Arts and Sciences and the National Academy of Sciences. She has served as Associate Editor for the Journal of the American Chemical Society and has held leadership roles such as President of the Inter-American Photochemical Society and Chair of the ACS Division of Inorganic Chemistry.

Research topics

• Chemistry
• Photochemistry
• Organic chemistry
• Atomic physics
• Materials science
• Optoelectronics
• Stereochemistry
• Optics
• Combinatorial chemistry
• Biochemistry
• Physics
• Inorganic chemistry

Selected publications

• Role of the Character of the Excited State of Singly Reduced Rh ₂ (II,II) Intermediates on Photocatalytic Activity

  Journal of the American Chemical Society · 2026-04-15

  articleOpen accessSenior authorCorresponding

  Singly reduced intermediates have recently been implicated as photoactive intermediates in a number of important reactions; however, their photophysical properties remain poorly understood. A series of dirhodium(II,II) complexes, cis-[Rh2(p-R-Form)2(bncn)2]2+ (bncn = benzo[c]cinnoline; p-R-Form = N,N′-di-p-R-phenylformamidinate), where R = −OCH3 (1), −CH3 (2), −H (3), −F (4), –Cl (5), and −CF3 (6), and their respective radical anions were prepared and their excited state properties were investigated. Complex 3 acted as a single-molecule photocatalyst for H2 production with red light. Substitution on the formamidinate ligands in 1–6 affected the energy of the Rh2(δ*)/Form(π,nb) highest occupied molecular orbital (HOMO), consistent with the metal/ligand-to-ligand charge transfer (1ML-LCT) absorption maxima and the 3ML-LCT excited state lifetime, ranging from 1.6 ns in 1 to 54 ns in 6 in CH3CN. The highest turnover number for photocatalytic H2 evolution was observed for 3, and the lowest values were for 1 and 6. The radical anion, [Rh2]−, formed during photocatalysis, was shown to absorb a photon and undergo a second reduction. The lifetimes of the doublet excited states of [3]− and [6]− were 0.49 and 0.24 ns, respectively. Calculations showed that the lowest energy excited state in [3]− was 2ML-LCT, whereas that in [6]− was a bncn– → Rh2(σ*) ligand-to-metal charge transfer (2LMCT) state. The 2LMCT state stabilized across the series from [1]− to [6]−, pointing at its role in modulating the photophysical properties. This work highlights the importance of the reductive quenching of [Rh2]− and the generation of the doubly reduced species to effectively catalyze hydrogen evolution.

  PublisherDOI

• Synergistic properties of biological interest of a ruthenium( <scp>ii</scp> ) compound

  Dalton Transactions · 2026-01-01

  article

  and release NO upon light stimulation, making it an interesting example of a synergetic compound possessing these properties simultaneously. Improving these results by adjusting the tridentate ligand provides a strategy to develop new Ru metallopharmaceutical candidates as anticancer drugs.

  PublisherDOI

• Recent Development of Ruthenium Complexes for Photochemotherapy (PCT) Applications

  2026-03-25

  book-chapter

  The increasing rates of cancer and common development of resistance to traditional platinum-based chemotherapeutics have inspired researchers to explore other treatment alternatives, particularly photoactive transition metal complexes. Ru(ii) complexes are a particular area of interest due to their versatile photochemical qualities. Upon light irradiation, photodynamic therapy (PDT) agents generate reactive oxygen species (ROS) to induce cell death. Photochemotherapy (PCT) agents, however, release a biologically active ligand or metal complex upon light irradiation while remaining inactive in the dark. Both PDT and PCT agents are attractive alternatives to traditional therapeutics due to their spatiotemporally controlled activation with light, limiting side effects. To address some of the limitations discovered with PDT agents, Ru(ii) PCT compounds have been developed to be generally cytotoxic to cancer cells and to target specific enzymes and subcellular locations to increase specificity for cancer cells.

  PublisherDOI

• Cyclometallated Co(III) Complexes with Lowest-Energy Charge Transfer Excited States Accessible with Visible Light

  Journal of the American Chemical Society · 2025-04-10 · 9 citations

  articleSenior authorCorresponding

  The Co(III) complexes, cis-[Co(ppy)2(L)]PF6, where ppy = 2-phenylpyridine and L = bpy (2,2′-bipyridine; 1), phen (1,10-phenanthroline; 2), and DAP (1,12-diazaperylene; 3), are reported and their photophysical properties were investigated to evaluate their potential as sensitizers for applications that include solar energy conversion schemes and photoredox catalysis. Calculations show that cyclometallation in the cis-[Co(ppy)2(L)]PF6 series affords strong Co(dπ)/ppy(π) orbital interactions that result in a Co/ppy(π*) highest occupied molecular orbital (HOMO) and a lowest unoccupied molecular orbital (LUMO) localized on the diimine ligand, L(π*). Complexes 1–3 exhibit relatively invariant oxidation potentials, whereas the reduction event is dependent on the identity of the diimine ligand, L, consistent with the theoretical predictions. For 3 a broad Co/ppy(π*) → L(π*) metal/ligand-to-ligand charge transfer (ML-LCT) absorption band is observed in CH3CN with a maxima at 507 nm, extending beyond 600 nm. Upon excitation of the 1ML-LCT transition, transient absorption features consistent with the population of a 3ML-LCT excited state with lifetimes, τ, of 3.0 ps, 4.6 and 42 ps for 1, 2 and 3 in CH3CN respectively are observed. Upon irradiation with 505 nm, 3 is able to reduce methyl viologen (MV2+), an electron acceptor commonly in photocatalytic schemes. To our knowledge, 3 represents the first heteroleptic molecular Co(III) complex that combines cyclometallation with a diimine ligand with lowest-lying metal-to-ligand charge transfer excited states able to undergo photoinduced charge transfer with low-energy green light. As such, the structural design of 3 represents an important step toward d6 photosensitizers based on earth abundant metals.

  PublisherDOI

• Design, Synthesis, and Photophysical Properties of Hybrid Porphyrin-Natural Product Compounds

  SSRN Electronic Journal · 2025-01-01

  preprintOpen access
  PublisherDOI

• CCDC 2370071: Experimental Crystal Structure Determination

  The Cambridge Structural Database · 2025-12-29

  datasetOpen accessSenior author

  An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

  PublisherDOI

• Dirhodium(II,II) Complexes as Panchromatic Single-Molecule Photocatalysts for Hydrogen Evolution

  Accounts of Chemical Research · 2025-06-02 · 3 citations

  articleSenior authorCorresponding

  ConspectusThe growing global energy demand and climate change have prompted a shift from carbon-based fuels to sustainable energy sources. Hydrogen production by harnessing solar energy and using abundant proton sources represents an attractive approach to addressing this crisis. Single-molecule single-chromophore photocatalysts, capable of both absorbing the incident photon and catalyzing the chemical transformation, are able to circumvent energy losses present in multicomponent systems that require a photosensitizer and a catalyst, often employing additional redox relay molecules. The series of complexes derived from cis-[Rh2(μ-DPhF)2(μ-bncn)2]2+ (1; DPhF = N,N′-diphenylformamidinate, bncn = benzo[c]cinnoline) discussed in this Account presents robust and air-stable single-molecule photocatalysts with panchromatic absorption from the ultraviolet spectral region to the near-infrared (NIR), with high turnover frequencies of ∼20 to 30 h–1 under red light irradiation. For comparison, other single-molecule hydrogen-evolving photocatalysts reported to date exhibit low photocatalytic efficiency, are not operable in the visible or NIR regions, and are unstable under an ambient atmosphere.Through ground state photophysical characterization and theoretical calculations, the highest occupied molecular orbital (HOMO) in this class of complexes was assigned to be centered on the Rh2(δ*)/Form(π/nb) MO, while the lowest occupied MO (LUMO) is localized on bncn(π*), with the lowest-energy absorption attributed to the HOMO → LUMO singlet metal/ligand-to-ligand charge transfer (1ML-LCT) transition. Emission observed at 77 K was assigned to arise from the 3ML-LCT state with an estimated excited-state reduction potential of ∼+1.0 V vs Ag/AgCl, making these complexes strong oxidizing agents upon illumination. The 3ML-LCT lifetimes of these complexes at room temperature range from 1 to 33 ns and are influenced by the presence of a low-lying metal-centered (3MC) state.Experiments designed to elucidate the mechanism for photocatalytic proton reduction have shown that the parent Rh2(II,II) molecule, [Rh2], undergoes two sequential photon absorption and reduction events generating [Rh2]2–, thus storing two redox equivalents. The ability of the singly reduced complex, [Rh2]−, to absorb a photon and oxidize substrates in solution from its excited state to generate [Rh2]2– represents a critical step in the catalytic cycle. Both isolated [Rh2]− and [Rh2]2– species are able to produce hydrogen in acidic media, making multiple simultaneous pathways possible during photocatalysis; however, the latter was shown to be more efficient and is independent of photocatalyst concentration. The active site for these Rh2 systems is localized on the bncn ligands without the formation of a Rh–H intermediate, under both electro- and photocatalytic conditions. During electrocatalysis, the bncn ligand acts as a proton relay for hydrogen evolution, supported by theoretical calculations suggesting interligand cooperativity for the formation of the H–H bond. The need for a Rh–H intermediate in the photocatalytic cycle has also been ruled out by coordinatively saturating the rhodium centers.This Account reviews the ground- and excited-state photophysical properties of Rh2(II,II) single-molecule photocatalysts for hydrogen evolution. The insights into the photo- and electrocatalytic mechanisms will not only aid in improving the catalytic performance of these [Rh2] systems but also provide a pathway to extend this reactivity to platforms composed of earth-abundant metals.

  PublisherDOI

• Kinetic trapping for the production of a long-lived ³ MLCT excited state in Fe( <scp>ii</scp> ) complexes

  Chemical Communications · 2025-01-01 · 1 citations

  articleCorresponding

  The formation of long-lived metal-to-ligand charge-transfer (MLCT) excited states in iron complexes has been challenging, but is critical for the development of affordable sensitizers for solar energy conversion. Iron complexes with extended aromatic ligands were prepared and their excited state properties are consistent with an MLCT state.

  PublisherDOI

• Positional Tuning of Ether-Substituted NIR Donor–Acceptor–Donor Fluorophores

  The Journal of Physical Chemistry A · 2025-10-31

  articleCorresponding

  Recent advancements in near-infrared (NIR) donor–acceptor–donor (D–A–D) fluorophore design have unveiled the potential of variations in its architecture for attaching solubilizing and/or shielding groups to enhance dye solubility and mitigate fluorescence quenching caused by aggregation and interactions with solvent. However, a significant gap in research exists regarding how these alterations in the molecular structure influence the photophysical properties of the fluorophore itself. In this study, we present a comprehensive analysis of the effect of the position of the donor substituent group on the stability and optical properties of a series of D–A–D NIR fluorophores. We conjugated thienothiadiazole (TTD) with six different methoxyphenyl or dimethoxyphenyl donors to form a library of D–A–D NIR fluorophores with methoxy substituents positioned ortho, meta, and/or para with respect to the acceptor. Our experimental findings, supported by density functional theory (DFT) calculations, reveal that the position of the methoxy donor is strongly linked to the emission wavelength, brightness, and stability. The para-positioned donor, for instance, yields a longer emission wavelength (907 nm) than its meta-positioned counterpart (888 nm), while the di-ortho substitution significantly compromises the photostability of the dye, likely due to steric strain. Overall, the para-positioned donors exhibit longer emission wavelengths (902–907 nm), while the meta-positioned donors offer quantum yields (0.88–0.90%) that are higher than those of their ortho- and para-positioned counterparts (0.31–0.47%), making them promising candidates for potential applications in bioimaging.

  PublisherDOI

• CCDC 2370070: Experimental Crystal Structure Determination

  The Cambridge Structural Database · 2025-12-29

  datasetOpen accessSenior author

  An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

  PublisherDOI

Recent grants

• Design of New Ru(II) Complexes to Control Excited State Reactivity

  NSF · $750k · 2018–2021

• Tuning the Excited States of New Ru(II) Complexes for Potential Photodynamic Therapy Applications

  NSF · $720k · 2012–2016

• Excited States of New Ru(II) Complexes: Controlling Reactivity

  NSF · $697k · 2015–2018

• Control of Excited State Dynamics of Ru(II) Complexes for Dual Activity

  NSF · $750k · 2021–2024

• Design, Synthesis, and Photochemistry of New Ru(II) Complexes as Potential Photo-Cisplatin Analogs

  NSF · $690k · 2009–2013

Frequent coauthors

• Kim R. Dunbar

  120 shared

• Jeremy J. Kodanko

  73 shared

• Daniel A. Lutterman

  52 shared

• Alfredo M. Angeles‐Boza

  University of Connecticut

  41 shared

• Patty K.‐L. Fu

  Governors State University

  41 shared

• A. Chouai

  University of Houston

  36 shared

• Judith C. Gallucci

  The Ohio State University

  33 shared

• Randolph P. Thummel

  University of Houston

  29 shared

Labs

• Claudia Turro LabPI

Awards & honors

• Jane Coffin Childs Memorial Fund for Medical Research Postdo…
• Early CAREER Award by the National Science Foundation (1998)
• Arnold and Mabel Beckman Foundation Young Investigator Award…
• Fellow of the American Chemical Society (2010)
• Fellow of the American Association for the Advancement of Sc…