Department of Chemistry

Publications by Year

    2014

  • 52. Pollum, M.; Martínez-Fernández, L.; Crespo-Hernández, C. E.; "Photochemistry of Nucleic Acid Bases and their Thio- and Aza-Analogues in Solution", Top. Curr. Chem. 2014, in press. Invited Review Chapter. Access article


  • 51. Pollum, M.; Crespo-Hernández, C. E.; "Communication: The dark singlet state as a doorway state in the ultrafast and efficient intersystem crossing dynamics in 2-thiothymine and 2-thiouracil", J. Chem. Phys. 2014, 140, 071101. Access article


  • 2013

  • 50. Reichardt, C.; Wen, C.; Vogt, R. A.; Crespo-Hernández, C. E.; "Role of Intersystem Crossing in the Fluorescence Quenching of 2-Aminopurine 2'-deoxyriboside in Solution", Photochem. Photobiol. Sci. 2013, 12, 1341-1350. Invited Manuscript; submitted as part of the themed issue on the "Interaction of UV Radiation with DNA". Access article


  • 49. Crespo-Hernández, C. E.; Vogt, R. A.; Sealey, B.;† "On the Primary Reaction Pathways in the Photochemistry of Nitro-Polycyclic Aromatic Hydrocarbons", Mod. Chem. Appl. 2013, 1, 106. † Fellow of the ACS Project SEED Program for economically disadvantage high school students. doi: 10.4172/ 2329-6798 .1000106 or Access article


  • 48. Fujiwara, T.; Reichardt, C.; Vogt, R. A.; Zgierski, M. Z.; Crespo-Hernández, C. E.; Lim, E. C. "Electronic Spectra and Excited-State Dynamics of 4-Fluoro-N,N-dimethylaniline", Chem. Phys. Lett. 2013, 586, 70-75. Access article


  • 47. Vogt, R. A.; Reichardt, C.; Crespo-Hernández, C. E.; "Excited-State Dynamics in Nitro-Naphthalene Derivatives: Intersystem Crossing to the Triplet Manifold in Hundreds of Femtoseconds", J. Phys. Chem. A 2013, 117, 6580-6588. Access article


  • 46. Vogt, R. A.; Crespo-Hernández, C. E.; "Conformational Control in the Population of the Triplet State and Photoreactivity of Nitronaphthalene Derivatives", J. Phys. Chem. A 2013, 117, 14100-14108. Access article


  • 2012

  • 45. Vogt, R. A.; Gray, T. G.; Crespo-Hernández, C. E.;"Subpicosecond Intersystem Crossing in Mono- and Di-(Organophosphine)gold(I) Naphthalene Derivatives in Solution", J. Am. Chem. Soc. 2012, 134, 14808–14817. Access article


  • 44. Isayev, O.; Crespo-Hernández, C. E.;Gorb, L.; Hill, F. C.; Leszczynski, J.; "In Silico Structure-Function Analysis of E. cloacae Nitroreductase", Proteins 2012, 80, 2728-2741. Access article


  • 2011

  • 43. Reichardt, C.; Guo, C.; Crespo-Hernández, C. E.;"Excited-State Dynamics in 6-Thioguanosine from the Femtosecond to Microsecond Time Scale", J. Phys. Chem. B 2011, 115, 3263-3270. Access article


  • 42. Dodson, L. G.;† Vogt, R. A.; Marks, J.;† Reichardt, C.; Crespo-Hernández, C. E.;"Photophysical and Photochemical Properties of the Pharmaceutical Compound Salbutamol in Aqueous Solutions", Chemosphere 2011, 83, 1513-1523. † Participated as undergraduate student. Access article


  • 41. Santos-Pérez, J.; Crespo-Hernández, C. E.; Reichardt, C.; Cabrera, C. R.; Feliciano-Ramos, I.; Arroyo-Ramírez, L.; Meador, M. A.; "Synthesis, Optical Characterization, and Electrochemical Properties of Isomeric Tetraphenylbenzodifurans Containing Electron Acceptor Groups", J. Phys. Chem. A 2011, 115, 4157-4168. Access article


  • 40. Díaz-Espinosa, Y.; Crespo-Hernández, C. E.; Alegría, A. E.; García, C.; Arce R.; "Quenching Enhancement of the Singlet Excited State of Pheophorbide-a by DNA in the Presence of the Quinone Carboquone", Photochem. Photobiol. 2011, 87, 275-283. Access article


  • 2010

  • 39. Reichardt, C.; Crespo-Hernández, C. E.; "Room-Temperature Phosphorescence of the DNA Monomer Analogue 4-Thiothymidine in Aqueous Solutions after UVA Excitation", J. Phys. Chem. Lett. 2010, 1, 2239-2243.Access article


  • 38. Reichardt, C.; Crespo-Hernández, C. E.; "Ultrafast Spin Crossover in 4-Thiothymidine in an Ionic Liquid", Chem. Comm. 2010, 46, 5963-5965.Access article


  • 37. Vogt, R. A.; Peay, M. A.; Gray, T. G.; Crespo-Hernández, C. E.; "Excited-State Dynamics of (Organophosphine)Gold(I) Pyrenyl Isomers", J. Phys. Chem. Lett. 2010, 1, 1205-1211.Access article


  • 2009

  • 36. Reichardt, C.; Vogt, R. A.; Crespo-Hernández, C. E.; "On the Origin of Ultrafast Nonradiative Transitions in Nitro-PAHs: Excited-State Dynamics in 1-Nitronaphthalene", J. Chem. Phys. 2009, 131, 224518.Access article


  • 35. de La Harpe, K.; Crespo-Hernández, C. E.; Kohler, B.; "Deuterium Isotope Effect on Excited-State Dynamics in an Alternating GC Oligonucleotide", J. Am. Chem. Soc. 2009, 131, 17557-17559.Access article


  • 34. Vogt, R. A.; Rahman, S.;† Crespo-Hernández, C. E., "Structure-Activity Relationships in Nitro-Aromatic Compounds", In Practical Aspects of Computational Chemistry. Methods, Concepts and Applications, Leszczynski, J.; Shukla, M. K., eds., Springer, Netherlands, 2009, pp. 217-240. † Participated as undergraduate student.Access article


  • 33. de La Harpe, K.; Crespo-Hernández, C. E.; Kohler, B., "The Excited-State Lifetimes in a G•C DNA Duplex are Nearly Independent of Helix Conformation and Base-Pairing Motif", ChemPhysChem (Special Issue in Biophysics) 2009, 10, 1421-1425. Access article


  • 32. Middleton, C. T.; de La Harpe, K.; Su, C.; Law, Y. K.; Crespo-Hernández, C. E.; Kohler, B., "DNA Excited-State Dynamics: From Single Bases to the Double Helix", Annu. Rev. Phys. Chem. 2009, 60, 217-239. Access article


  • 2008

  • 31. Close, D. M.; C. E. Crespo-Hernández; L. Gorb; J. Leszczynski, "Ionization Energy Thresholds of Microhydrated Adenine and Its Tautomers", J. Phys. Chem. A 2008, 112, 12702-12706. Access article


  • 30. C. E. Crespo-Hernández; K. de La Harpe; B. Kohler; "Ground-State Recovery Following UV Excitation is Much Slower in G·C-DNA Duplexes and Hairpins Than in Mononucleotides", J. Am. Chem. Soc. 2008, 130, 10844-10845. Access article


  • 29. C. E. Crespo-Hernández; Burdzinski, G.; Arce, R.; "Environmental Photochemistry of Nitro-PAHs: Direct Observation of Ultrafast Intersystem Crossing in 1-Nitropyrene", J. Phys. Chem. A 2008, 112, 6313-6319. Access article


  • 28. T. Takaya; C. Su; K. de La Harpe; C. E. Crespo-Hernández; B. Kohler; "UV Excitation of DNA and RNA Strands Produces High yields of exciplex states between two stacked bases", Proc. Natl. Acad. Sci. USA 2008, 105, 10285-10290. Access article


  • 27. Close, D. M.; C. E. Crespo-Hernández; L. Gorb; J. Leszczynski, "Theoretical elucidation of conflicting experimental data on vertical ionization potentials of microhydrated thymine", J. Phys. Chem. A 2008, 112, 4405-4409. (SELECTED AS A HIGH-IMPACT LETTER)Access article


  • 26. Y. K. Law; J. Azadi;† C. E. Crespo-Hernández; E. Olmon;† B. Kohler; "Prediction of Thymine Dimerization Yields from Molecular Dynamics Simulations", Biophysical J. 2008, 94, 3590-3600. † Participated as undergraduate student.Access article


  • 2007

  • 25. C. E. Crespo-Hernández; C. N. J. Marai,† "Vertical Singlet Excitations on Adenine Dimer: A Time Dependent Density Functional Study", AIP Conference Proceedings, 2007, 963, 607-610. † Participated as undergraduate student.Access article
  • 24. C. E. Crespo-Hernández; D. M. Close; L. Gorb; J. Leszczynski, "Determination of Redox Potentials for the Watson-Crick Base Pairs, DNA Nucleosides, and Relevant Nucleosides Analogs", J. Phys. Chem. B 2007, 111, 5386-5395. Access article
  • 23. W. J. Schreier; T. E. Schrader; F. O. Koller; P. Gilch; C. E. Crespo-Hernández; V. N. Swaminathan; T. Carell; W. Zinth; B. Kohler, "Thymine Dimerization in DNA is an Ultrafast Photoreaction", Science 2007, 315, 625-629. Access article
  • 22. P. M. Hare; C. E. Crespo-Hernández; B. Kohler, "Internal Conversion to the Electronic Ground State Occurs via Two Distinct Pathways for Pyrimidine Bases in Aqueous Solution", Proc. Natl. Acad. Sci. USA 2007, 104, 435-440. Access article


  • 2006

  • 21. P. M. Hare; C. E. Crespo-Hernández; B. Kohler, "Solvent-Dependent Photophysics of 1-cyclohexyluracil: Ultrafast Branching in the Initial Bright State Leads Nonradiatively to the Electronic Ground State and a Long-Lived 1np State", J. Phys. Chem. B 2006, 110, 18641-18650. Access article
  • 20. L. Colón; C. E. Crespo-Hernández; R. Oyola; C. García; R. Arce, "Photochemical and Photophysical Properties of the A·T Sequence Isomers: An Experimental and Theoretical Approach", J. Phys. Chem. B 2006, 110, 15589-15596. Access article
  • 19. C. E. Crespo-Hernández; B. Cohen; B. Kohler, "Molecular spectroscopy: Complexity of Excited-State Dynamics in DNA (Reply)", Nature (Brief Communications Arising) 2006, 441, E7-E8. Access article
  • 18. D. M. Close; C. E. Crespo-Hernández; L. Gorb; J. Leszczynski, "The Influence of Microhydration on the Ionization Energy Thresholds of Thymine: Comparisons of Theoretical Calculations with Experimental Values", J. Phys. Chem. A 2006, 110, 7485-7490. Access article


  • 2005

  • 17. D. M. Close; C. E. Crespo-Hernández; L. Gorb; J. Leszczynski, "The Influence of Microhydration on the Ionization Energy Thresholds of Uracil and Thymine", J. Phys. Chem. A 2005, 109, 9279-9283. Access article
  • 16. C. E. Crespo-Hernández; B. Cohen; B. Kohler, "Base Stacking Controls Excited-State Dynamics in A·T-containing DNA", Nature 2005, 436, 1141-1144. Access article


  • 2004

  • 15. B. Cohen; C. E. Crespo-Hernández; B. Kohler, "Strickler-Berg Analysis of Excited Singlet State Dynamics in DNA and RNA Nucleosides", J. Chem. Soc., Faraday Discuss. 2004, 127, 137-147. Access article
  • 14. C. E. Crespo-Hernández; B. Kohler, "Influence of Secondary Structure on Electronic Energy Relaxation in Adenine Homopolymers", J. Phys. Chem. B 2004, 108, 11182-11188. Access article
  • 13. C. E. Crespo-Hernández; R. Arce; Y. Ishikawa; L. Gorb; J. Leszczynski; D. M. Close, "Ab initio Ionization Energy Thresholds of DNA and RNA Bases in Gas Phase and in Aqueous Solution", J. Phys. Chem. A 2004, 108, 6373-6377. Access article
  • 12. B. Cohen; C. E. Crespo-Hernández; P. M. Hare; B. Kohler, "Ultrafast Excited-State Dynamics in DNA and RNA Polymers", In Femtochemistry and Femtobiology: Ultrafast Events in Molecular Science; Martin, M.; Hynes, J. T.; Elsevier: Amsterdam, 2004, p. 463-470. Access article
  • 11. C. E. Crespo-Hernández; B. Cohen; P. M. Hare; B. Kohler, "Ultrafast Excited-State Dynamics in Nucleic Acids", Chem. Rev. 2004, 104, 1977-2019. Access article
  • 10. C. E. Crespo-Hernández; R. Arce, "Formation of Formamidopyrimidine Nucleobase and Nucleoside as Major Products in the 254 nm Low-Intensity and 266 nm High-Intensity Irradiation of the Guanine Derivatives in Unbuffered Aqueous Solution", J. Photochem. Photobiol. B: Biol. 2004, 73, 167-175. Access article


  • 2003

  • 9. C. Crespo-Hernández; R. Arce; E. Quiñones, "Magnetic Field Enhancement of the 6-Methylpurine Photoionization Yield", Chem. Phys. Lett. 2003, 382, 661-664. Access article
  • 8. C. E. Crespo-Hernández; R. Arce, "Near Threshold Photo-Oxidation of Dinucleotides Containing Purines upon 266 nm Nanosecond Laser Excitation. The Role of Bases Stacking, Conformation, and Sequence", J. Phys. Chem. B 2003, 107, 1062-1070. Access article


  • 2002

  • 7. C. E. Crespo-Hernández; R. Arce, "Photoinization of DNA and RNA Bases, Nucleosides and Nucleotides through a Combination of One- and Two-photon Pathways upon 266 nm Nanosecond Laser Excitation", Photochem. Photobiol. 2002, 76, 259-267. Access article
  • 6. C. E. Crespo-Hernández; L. Martínez; A. E. González-Sierra; A. Díaz-Vázquez; R. Arce, "The 254 nm Low Intensity and 266 nm Laser Photochemistry of Adenosine. Effect of pH and Concentration on the Reactive Precursors of the Principal Products, Adenine and FAPyAde", J. Photochem. Photobiol. A: Chem. 2002, 152, 123-133. Access article
  • 5. C. E. Crespo-Hernández, "Photochemical studies of DNA and RNA Bases, Nucleosides, Nucleotides, and Dinucleotides", Dissertation, University of Puerto Rico, Río Piedras, Puerto Rico, UMI, Order No. DA3083759, 2002, CAN 141:309127, AN 2004:104500.


  • 2001

  • 4. E. E. Méndez; C. Crespo-Hernández; R. Figueroa; R. Arce; E. Quiñones, "Water Photoreduction Through the Direct Photoexcitation of Methylviologen", J. Photochem. Photobiol. A: Chem. 2001, 142, 19-24.Access article


  • 2000

  • 3. C. E. Crespo-Hernández; R. Arce, "Part II. Mechanisms of Formation of Guanine as One of the Major Products in the 254 nm Photolysis of Guanine Derivatives: The Concentration and pH Effect", Photochem. Photobiol. 2000, 71, 544-550. Access article
  • 2. C. E. Crespo-Hernández; S. Flores; C. Torres; I. Negrón-Encarnación; R. Arce, "Part I. Photochemical and Photophysical Studies of Guanine Derivatives: Intermediates Contributing to its Photodestruction Mechanism in Aqueous Solution and the Participation of the Electron Adduct", Photochem. Photobiol. 2000, 71, 534-543. Access article
  • 1. C. A. Reyes; M. Medina; C. E. Crespo-Hernández; M. Z. Cedeño; R. Arce; O. Rosario; M. E. Sigman; R. Dabestani, "The Photochemistry of Pyrene in Nonactivated Silica Gel Surfaces as a Model of Atmospheric Particulate", Environ. Sci. Technol. 2000, 34, 415-421. Access article