Tibetts [View Image]

Katharine Tibbetts, Ph.D.

Associate Professor
(804) 828-7515
Oliver Hall 4020


A.B., Princeton University, 2005
Ph.D., Princeton University, 2012
Graduate Intern, Sandia National Laboratories, 2011
Postdoctoral Fellow, Temple University, 2012-2015

Honors and awards

  • National Science Foundation Graduate Research Fellowship, 2006-09
  • Centennial Fellowship, Princeton University, 2006-11
  • Hubert Alyea Teaching Award, Princeton University, 2008
  • Fulbright Fellowship in Germany, 2005-2006

Group website

Tibbetts group website

Research interests

The Tibbetts group investigates chemical reactions induced by strong-field femtosecond laser excitation of gas- and condensed-phase molecules. The short time duration (~10-14 s) and high electric field strength (~5 V/Å) of femtosecond laser pulses make them ideal for both inducing nonequilibrium chemical transformations and probing reaction dynamics in real time. Current research areas focus on (1) synthesizing metal-based nanoparticles from metal salt precursors and elucidating reaction mechanisms for these transformations in the condensed phase, and (2) probing and controlling the dissociation dynamics of polyatomic radical cations in the gas phase.

Synthesis of metal and composite nanoparticles

Metal nanoparticles with tailored sizes possess many unique optical and electronic properties that make then useful for applications such as catalysis and sensing. While many chemical synthetic routes to these types of nanomaterials exist, femtosecond laser reduction of metal salt precursors has the advantages of avoiding the use of environmentally damaging reducing agents and organic surfactants that can limit practical use of the resulting materials. Combining metal-salt reduction with laser ablation of a solid surface immersed in the solution enables the synthesis of additional composite nanomaterials with metastable phases. Current projects include controlling metal salt reduction kinetics and metal nanoparticle sizes using hydroxyl radical scavengers, synthesizing ultrasmall metal-oxide and metal-carbon nanocomposite catalysts from metal salt and organometallic precursors, and depositing metal nanoparticles onto silicon laser-induced periodic surface structures (LIPSS) for surface-enhanced Raman spectroscopy (SERS) sensing applications. Future work will focus on extending these synthetic techniques to earth-abundant metals such as Fe, Co, and Ni.

Dissociation dynamics of gas-phase polyatomic radical cations

Determining unimolecular dissociation mechanisms of radical cations is important to understand fundamental processes including ionizing radiation-induced DNA damage and initial energy release pathways in energetic molecules. Femtosecond time-resolved “pump-probe” measurements can follow these dissociation reactions on their natural timescales. Combined with quantum-chemical calculations of cationic electronic potential energy surfaces and reaction intermediates, these measurements can determine the reaction mechanisms with exquisite detail. Current projects focus on the reactions of organic phosphonates and phosphates as models for the DNA sugar-phosphate backbone and nitrotoluenes as models for nitroaromatic explosives. Future work will explore model systems for the deoxyribose sugar and nucleobases, as well as high-nitrogen content energetic molecules such as tetrazoles.


Publications at VCU

K. M. Tibbetts, “Coherent vibrational and dissociation dynamics of polyatomic radical cations”, Chem. Eur. J. 2019 DOI:10.1002/chem.201900363

D. Ampadu Boateng, M. D. Word, and K. M. Tibbetts, “Probing Coherent Vibrations of Organic Phosphonate Radical Cations with Femtosecond Time-Resolved Mass Spectrometry”, Molecules 2019, 24, 509

D. Ampadu Boateng, M. D. Word, L. G. Gutsev, P. Jena, and K. M. Tibbetts, “Conserved Vibrational Coherence in the Ultrafast Rearrangement of 2-Nitrotoluene Radical Cation”, J. Phys. Chem. A 2019, 123, 1140-1152

M. G. John and K. M. Tibbetts, “One-step femtosecond laser ablation synthesis of sub-3 nm gold nanoparticles stabilized by silica”, Appl. Surf. Sci. 2019, 475, 1048-1057

C. J. Rodrigues, J. A. Bobb, M. G. John, S. P. Fisenko, M. S. El-Shall, and K. M. Tibbetts, “Nucleation and growth of gold nanoparticles initiated by nanosecond and femtosecond laser irradiation of aqueous [AuCl4]-”, Phys. Chem. Chem. Phys. 2018, 20, 28465-28475

D. Ampadu Boateng and K. M. Tibbetts, “Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization” J. Vis. Exp. 2018, e58263

D. Ampadu Boateng, G. L. Gutsev, P. Jena, and K. M. Tibbetts, “Dissociation dynamics of 3- and 4-nitrotoluene radical cations: Coherently driven C-NO2 bond homolysis” J. Chem. Phys. 2018, 148, 134305

V. K. Meader, M. G. John, L. M. Frias Batista, S. Ahsan, and K. M. Tibbetts, “Radical Chemistry in a Femtosecond Laser Plasma: Photochemical Reduction of Ag+ in Liquid Ammonia Solution” Molecules 2018, 23, 532

D. Ampadu Boateng, G. L. Gutsev, P. Jena, and K. M. Tibbetts, “Ultrafast Coherent Vibrational Dynamics in Dimethyl Methylphosphonate Radical Cation” Phys. Chem. Chem. Phys. 2018, 20, 4636-4640

G. L. Gutsev, D. Ampadu Boateng, P. Jena, and K. M. Tibbetts, “A Theoretical and Mass Spectrometry Study of Dimethyl Methylphosphonate: New Isomers and Cation Decay Channels in an Intense Femtosecond Laser Field” J. Phys. Chem. A 2017, 121, 8414-8424

V. K. Meader, M. G. John, C. J. Rodrigues, and K. M. Tibbetts, “Roles of Free Electrons and H2O2 in the Optical Breakdown-Induced Photochemical Reduction of Aqueous [AuCl4]” J. Phys. Chem. A 2017, 121, 6742-6754

K. M. Tibbetts, X.-J. Feng, and H. Rabitz, “Exploring experimental fitness landscapes for chemical synthesis and property optimization” Phys. Chem. Chem. Phys. 2017, 19, 4266-4287

Select publications from postdoctoral and graduate work

K. M. Tibbetts, B. Tangeysh, J. H. Odhner, and R. J. Levis, “Elucidating Strong Field Photochemical Reduction Mechanisms of Aqueous [AuCl4]-: Kinetics of Multiphoton Photolysis and Radical-Mediated Reduction” J. Phys. Chem. A 2016, 120, 3562-3569

K. M. Tibbetts, M. Tarazkar, T. Bohinski, D. A. Romanov, S. Matsika, and R. J. Levis, “Controlling the Dissociation Dynamics of Acetophenone Radical Cation Through Excitation of Ground and Excited State Wavepackets” J. Phys. B: Opt. At. Mol. Phys. 2015, 48, 164002

B. Tangeysh, K. M. Tibbetts, J. H. Odhner, B. B. Wayland, and R. J. Levis, “Triangular Gold Nanoplate Growth by Oriented Attachment of Au Seeds Generated by Strong Field Laser Reduction” Nano Lett. 2015, 15, 3377-3382

T. Bohinski, K. M. Tibbetts, M. Tarazkar, D. A. Romanov, S. Matsika, and R. J. Levis, “Strong Field Adiabatic Ionization Prepares a Launch State for Coherent Control” J. Phys. Chem. Lett. 2014, 5, 4305-4309

T. Bohinski, K. M. Tibbetts, M. Tarazkar, D. A. Romanov, S. Matsika, and R. J. Levis, “Measurement of an Electronic Resonance in a Ground-State, Gas-Phase Acetophenone Cation via Strong-Field Mass Spectrometry” J. Phys. Chem. Lett. 2013, 4, 1587-1591

K. M. Tibbetts, X. Xing, and H. Rabitz, “Exploring Control Landscapes for Laser-Driven Molecular Fragmentation” J. Chem. Phys. 2013, 139, 144201

K. M. Tibbetts, X. Xing, and H. Rabitz, “Optimal Control with Homologous Families of Photonic Reagents and Chemical Substrates” Phys. Chem. Chem. Phys. 2013, 15, 18012-1802

K. W. Moore, A. Pechen, X.-J. Feng, J. Dominy, V. Beltrani, and H. Rabitz, “Universal Characteristics of Chemical Synthesis and Property Optimization” Chem. Sci. 2011, 2, 417-424

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