21st Biannual: John Eisch Lectureship In
Inorganic Chemistry
Friday, April 17, 2026
4 P.M.
Smart Energy Building, Fountain Room
Professor Claudia Turro
Chair and Dr. Melvin L. Morris Professor
Department of Chemistry and Biochemistry
The Ohio State University, Columbus, OH
Excited States of Transition Metal Complexes for Applications in Solar Energy Conversion and Medicine
Molecules that absorb visible light may use this energy provided photons to access reactions not possible from their ground electronic states. These excited state molecules can then be used for a number of applications, including sensors, solar energy conversion schemes, and photomedicine. The use of light to activate the action of a drug has become important as mode of cancer therapy because it is significantly less invasive and poses low levels of systemic toxicity to the patient, thus reducing undesirable side effects. Photoinduced ligand exchange has been used to release drugs with spatiotemporal control which, together with the production of 1O2, represent a new, more effective dual-activity mode of action. These photoinduced reactions of Ru(II) complexes will be presented, along with their activity towards biological targets and cancer cells. The dual-modality complexes were shown to exhibit significant enhancement of activity stemming from their ability to induce cell death through two different, independent pathways. These new dual-action complexes provide a new platform for drug delivery and enhanced therapeutic activity upon excitation with low energy light.
The search for renewable, clean sources of energy is critical for the future of the planet. Harnessing sunlight and transforming its energy from abundant small molecules into storable clean fuels, such as hydrogen from water, has great potential to help meet the growing global demands, but remains a challenge. Systems for the production of solar fuels require strong light absorption that is well-matched to the solar spectrum, with excited states able to transfer electrons to catalysts that effect the desired transformation. Typically, a light absorber (LA) is combined with a hydrogen evolving catalyst (HEC) into functional LAHEC architectures (Figure 1a). LAs currently used in these applications typically do not absorb beyond ~500 nm, such that a large fraction of photons that make up the solar spectrum are not utilized. In addition, multi-component LA-HEC platforms inherently lose energy through charge transfer steps. We have developed new Rh2(II,II) complexes that that absorb light strongly throughout the visible region and into the near-IR. These compounds are able to undergo excited state redox processes, and some are able to act as single-molecule photocatalysts for the production of hydrogen with red and near-IR light (Figure 1b).
One example of a single-molecule photocatalyst, cis– [Rh2(DPhF)2(bncn)2](BF4)2 (DPhF = N,N’-diphenylformamidinate, bncn = benzo[c]cinnoline; 1), is shown in Figure 1b, along with the turnover numbers (TONs) for H2 production upon irradiation with 670 nm light in the presence of acid and a sacrificial electron donor. The mechanism of photo- and electrocatalysis by 1 and related complexes will be discussed, which show that these bimetallic complexes are able to store two electrons upon the stepwise absorption of two low-energy photons to produce the catalytically-active doubly-reduced complex. Mechanistic aspects of the reduction of protons to H2 by [1]2– will be discussed, along with new systems for rhodiumfree photocatalysis.
- Information about Professor Claudia Turro
Claudia Turro received her BS with honors in 1987 from Michigan State University. She worked with Daniel G. Nocera and George E. Leroi at Michigan State University and received her PhD in 1992. She was awarded a Jane Coffin Childs Memorial Fund for Medical Research Postdoctoral Fellowship to conduct postdoctoral work at Columbia University with Nicholas J. Turro (no relation) from 1992 to 1995 and has been a faculty member at The Ohio State University since 1996. She received the Early CAREER Award by the National Science Foundation in 1998, the Arnold and Mabel Beckman Foundation Young Investigator Award in 1999, was named a 2010 Fellow of the American Chemical Society (ACS), and a 2012 Fellow of the American Association for the Advancement of Science. She was elected President of the Inter-American Photochemical Society (2012-14) and Chair of the ACS Division of Inorganic Chemistry (2016). She received the 2014 College of Arts and Sciences Susan M. Hartmann Mentoring and Leadership Award, the 2014 Award in Photochemistry from the Inter-American Photochemical Society, the 2016 Edward W. Morley Medal from the Cleveland Section of the ACS, the 2016 Award of the Columbus Section of the ACS, and the 2019 College of Arts and Sciences Harlan Hatcher Distinguished Faculty Award. Since 2016, she has been serving as Associate Editor for the Journal of the American Chemical Society. Professor Turro was elected a Member of the American Academy of Arts and Sciences in 2023 and a Member of the National Academy of Sciences in 2024.
- Information about Professor John J. Eisch
John Joseph Eisch joined the Department of Chemistry at Binghamton University in 1972, as chair and professor of chemistry, with the mandate of fostering the national reputation of its graduate teaching and research. Over the next six years as chair, he guided the recruiting of six senior and junior faculty with this goal in mind, while expanding his own research in organometallic chemistry to a yearly group of eight to 12 graduate and postdoctoral students, with support from federal and industrial resources. In 1983, his composite achievements were recognized by his promotion to the SUNY-wide rank of distinguished professor of chemistry. Further recruiting, notably during the chair tenure of professors Eugene Stevens, Alistair Lees, Wayne Jones and currently, Eriks Rozners, expanded the scope of advanced research into areas of immediate importance, such as nano materials, homogeneous catalysis, analytical sensors, biological transformations and energy storage.
Eisch received the BS degree in chemistry, summa cum laude, from Marquette University in 1952; earned the PhD degree in 1956, with Henry Gilman, at Iowa State University; and served as Union Carbide Research Fellow with Karl Ziegler at the Max-Planck-Institut für Kohlenforschung, Mülheim, Germany (1956–57). After junior professional appointments at St. Louis University and the University of Michigan, he became ordinary professor and department head at the Catholic University of America (1963–1972). He retired from his professorial career of 57 years in 2014, the latter 42 years of which were spent at Binghamton University.
The Eisch Group initially had concentrated on the preparation and organic synthetic uses of organometallic reagents of Li, Na, Mg, B and Al, but we were struck by the lack of definitive molecular mechanistic studies in previous work. In ensuing research encompassing reaction kinetics, trapping of any intermediates, IR, UV and X-ray crystallographic measurements, both heterolytic and homolytic C-M cleavages could be involved, as well as 4-centertrapesoidal transition states. Reviews are available in a) “Fifty Years of Ziegler- Natta Polymerization: From Serendipity to Science,” Organometallics, 2012, 31, 4917–4932 and b) Dalton Transactions, (DOI: 10:1039/c4dt010362) “Emergence of Electrophilic Alumination as the Counterpart of Established Nucleophilic Lithiation.” The original seven articles dealing with the reactions of RLi with the azomethyne groups have been recently published by the Eisch and the Rheingold Crystallographic Group in the European Journal of Organic Chemistry.
Over the years, the research involved the fruitful collaboration of more than 200 students as master’s, doctoral, postdoctoral or baccalaureate associates. The results have been reported in more than 410 scientific publications, in some 280 invited lectures worldwide, in the monograph “The Chemistry of Organometallic Compounds” (Macmillian, 1967) and in the edited series, “Organometallic Syntheses” (four volumes, J. J. Eisch and R. B. King, authors and editors). He has been an industrial consultant on organometallic chemistry and an expert witness in several patent litigations on Ziegler-Natta polymerization catalysis.
One of the significant discoveries of our studies is that the reaction of organic carbanionic reagents is not a one-step nucleophilic C alpha attack (i) but a two-step electrontransfer and electron-coupling process (ii)(iii).
- Previous Lectureship Recipients
2012
Stephen L. Buchwald - MIT
“Palladium-Catalyzed CarbonNitrogen and Carbon-Carbon Bond-Forming Reactions: Progress, Applications and Mechanistic Studies”
2013
David W. C. MacMillan - Princeton University
“The Use of Photoredox Catalysis in New Organic Bond Forming Reactions”
2014
Brian M. Stoltz - California Institute of Technology
“Complex Natural Products as a Driving Force for Discovery in Organic Chemistry”
2015
Eric N. Jacobsen - Harvard University
“Anion-Binding Catalysis”
2016
Bob Crabtree - Yale University
“Organometallic Catalysis for Solar Fuels and Storage”Phil S. Baran - The Scripps Research Institute
“Translational Chemistry”
2017
Stephen J. Lippard - MIT
“Understanding and Improving Platinum Anticancer Drugs”Daniel A. Singleton - Texas A&M Uniersity
“Dynamic Effects and Energy Labeling in Free-Radical Reactions”
2018
Clifford P. Kubiak - University of California, San Diego
“If You Make a Solar Fuel From CO2, What Should It Be?”Scott E. Denmark - University of Illinois at Urbana-Champaign
"Lewis-base Activation of Lewis Acids: An Evolving Paradigm for Catalysis in Main Group Chemistry"
2019
Professor Gregory C. Fu - California Institute of Technology "Nucleophilic Substitution Reactions: A Radical Alternative to SN1 and SN2 Reactions"
John F. Hartwig - University of California, Berkeley
"Selective, Catalytic Functionalization of C-H Bonds with Small and Large Catalysts"
2021
Professor Vern L. Schramm - Albert Einstein College of Medicine
"Enzymatic Transition States and Transition State Analogues"
2022
Karen Goldberg - University of Pennsylvania
"Molecular Oxygen as a Reagent in Late Transition Metal Organometallic Chemistry"
2023
Kendall N. Houk - University of California, Los Angeles "Pericyclic Reactions: Theory, Mechanisms, Dynamics and Role in Biology"
Polly L. Arnold - University of California, Berkeley
"F-Block Dinitrogen Chemistry; from Rarity to Catalysis in a Few Simple Steps"
2024
Professor Gregory H. Robinson - University of Georgia
"N-Heterocyclic Carbenes and Dithiolene Radicals: Counterintuitive Main Group Chemistry"
2025
Professor Melanie Sanford - Moses Gomberg Distinguished University Professor of Chemistry and Arthur F. Thurnau Professor Department of Chemistry University of Michigan
"Development of Metal-Catalyzed Reactions for Introducing Fluorine Into Organic Molecules"Dr. T. Don Tilley - University of California at Berkeley and Lawrence Berkeley National Laboratory Department of Chemistry
"Oxo Metal Clusters in Water Splitting and Bond Activations"Professor Tomislav Rovis - Samuel Latham Mitchill Professor of Chemistry
Department of Chemistry Columbia University
"Redshifting Photoredox Catalysis"