Carlos E. Crespo-Hernández

Professor and Associate Dean for Research

Millis Science Building, Room 219









Faculty Office: Millis Science Building, Room 219A

​Associate Dean Office: Crawford Building, Room 715

Associate Editor for Photochemistry Photobiology:

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Analytical, Biophysical, Organic, Physical, and Quantum Chemistry, Photochemistry, Ultrafast Spectroscopy, Time-Resolved Electronic Spectroscopy, Chemical Dynamics and Kinetics, Photodynamic Therapy, Photochemotherapy, Photomedicines, Computational Chemistry, Energy


Author Profiles

Web of Science

Google Scholars




  • Research Associate of Chemistry, The Ohio State University (2005-2006)
  • NIH Postdoctoral Fellow, The Ohio State University (2002-2005)
  • PhD, University of Puerto Rico, San Juan Campus, 2002
  • BS, University of Puerto Rico, San Juan Campus, 1995
  • Associate Dean for Research, College of Arts and Sciences, Case Western Reserve University (2021-present)
  • Professor of Chemistry, Case Western Reserve University (2019-present)
  • Associate Professor of Chemistry, Case Western Reserve University (2014-2019)
  • Co-Director of the Center for Chemical Dynamics, Case Western Reserve University (2008-2018)
  • Assistant Professor of Chemistry, Case Western Reserve University (2007-2014)
  • Visiting Professor, University of Puerto Rico, Humacao Campus (2006-2007)



Diversity, Inclusion, and Research Statement

The Crespo Research Group celebrates our individualities in race, ethnicity, gender, country of
origin, sexual orientation, and gender identity as a means to learn from one another as we work
collectively to train the next generation of investigators, educators, and professionals, solve
difficult research problems, and improve the understanding of chemistry and related fields.

Our group focuses on probing and understanding light-induced phenomena in molecules,
biopolymers, and cells. Primary applications include photodynamic therapy and
photomedicines, light harvesting and energy conversion, and environmental organic
photochemistry. There are three major areas of ongoing research: (1) excited-state dynamics
and photochemistry of DNA/RNA nucleobases and nucleobase derivatives and their
implications in the molecular origins of life; (2) design, synthesis, and investigation of organic
molecules as photomedicines and for photodynamic therapy applications; and (3) excited-state
dynamics and photochemistry of environmental pollutants, heteroatomic polycyclic aromatic
compounds, and bioorganic molecules.

Our group use analytical instrumentation and time-resolved spectroscopic techniques to
produce specific knowledge of the factors controlling these photo-processes. Students involved
in these scientific activities acquire expertise in a wide variety of analytical techniques such as
high-performance liquid chromatography, circular dichroism, infrared and ultraviolet-visible
spectrophotometric techniques, and time-resolved instrumentation on time scales ranging
from femtoseconds to microseconds. The experimental work is complemented with ground-
and excited-state computational methods.


Selected Publications

  • Hoehn, S. J.; Caldero-Rodríguez, N. E.; Crespo-Hernández, C. E., “Photochemistry of RNA, RNA Monomers and their Plausible Prebiotic Precursors” (Invited Review Chapter), In DNA Photodamage: From Light Absorption to Cellular Responses and Skin Cancer; Douki, T.; Improta, R., eds., RSC publishing in Comprehensive Series in Photochemical & Photobiological Sciences, 2022, Chapter 9, pp. 197-226. Access article
  • Sharma, D.; Zagore, L. L.; Brister, M. M.; Ye, X.; Crespo-Hernández, C. E.; Licatalosi, D. D.; Jankowsky, E., “The Kinetic Landscape of an RNA Binding Protein in Cells”, Nature2021, 591, 152–156. Access article
  • Ortiz-Rodríguez, L. A.; Hoehn, S. J.; Loredo, A.; Wang, L.; Xiao, H.; Crespo-Hernández, C. E., “Electronic Relaxation Pathways in Heavy-Atom-Free Photosensitizers Absorbing Near-Infrared Radiation and Exhibiting High Yields of Singlet Oxygen Generation”, J. Am. Chem. Soc. 2021, 143, 7, 2676–2681. Access article
  • Ortiz-Rodríguez, L. A.; Crespo-Hernández, C. E., “Thionated Organic Compounds as Emerging Heavy-Atom-Free Photodynamic Therapy Agents”, Chem. Sci. 2020, 11, 11113-11123. Invited Minireview. Access article
  • Ortiz-Rodríguez, L. A.; Reichardt, C.; Hoehn, S. J.; Jockusch, S.; Crespo-Hernández, C. E., “Detection of the thietane precursor in the UVA formation of the DNA 6-4 photoadduct”, Nature Commun. 2020, 11, 3599. Access article
  • Farrell, K. M.; Brister, M. M.; Pittelkow, M.; Sølling, T. I.; Crespo-Hernández, C. E., “Heavy-Atom Substituted Nucleobases in Photodynamic Applications: Substitution of Sulfur with Selenium in 6-Thioguanine Induces a Remarkable Increase in the Rate of Triplet Decay in 6-Selenoguanine”, J. Am. Chem. Soc. 2018, 140, 11214-11218. Access article
  • Pollum, M.; Minh, L.; Jockusch, S.; Crespo-Hernández, C. E., “Dithionated Nucleobases as Effective Photodynamic Agent Against Human Epidermoid Carcinoma Cells”, ChemMedChem 2018, 13, 1044-1050. Access article
  • Mai, S.; Pollum, M.; Martínez-Fernández, L.; Dunn, N.; Marquetand, P.; Corral, I.; Crespo-Hernández, C. E.; González, L. “The Origin of Efficient Triplet State Population in Sulfur-Substituted Nucleobases”, Nature Commun.2016, 7, 13077 (DOI: 10.1038/ncomms13077). Access article
  • Pollum, M.; Ashwood, B.; Jockusch, S.; Lam, M; Crespo-Hernández, C. E. “Unintended Consequences of Expanding the Genetic Alphabet”, J. Am. Chem. Soc.2016, 138, 11457-11460. Access article
  • Crespo-Hernández, C. E.; Martínez-Fernández, L.; Rauer, C.; Reichardt, C.; Mai, S.; Pollum, M.; Marquetand, P.; González, L.; Corral, I. “Electronic and Structural Elements that Regulate the Excited-State Dynamics in Purine Nucleobase Derivatives”, J. Am. Chem. Soc.2015, 137, 4368-4381. Access article
  • Pollum, M.; Jockusch, S.; Crespo-Hernández, C. E.; “2,4-Dithiothymine as a Potent UVA Chemotherapeutic Agent”, J. Am. Chem. Soc. 2014, 136, 17930-17933. Access article