Education

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

VCU Outstanding Early Career Faculty Award, 2020
Presidential Early Career Award in Science and Engineering (PECASE), 2019
VCU CHS Excellence in Scholarship in Math and Sciences Award, 2019

---

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 and carbon-based nanomaterials using laser methods and elucidating reaction mechanisms for these transformations, and (2) probing and controlling the dissociation dynamics of polyatomic radical cations in the gas phase.

Laser synthesis of nanomaterials

Metal nanoparticles, metal-oxide composites, and carbon-based nanomaterials with tailored compositions and structures 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, laser synthesis has the advantages of avoiding the use of environmentally damaging reducing agents and organic surfactants that can limit practical use of the resulting materials. Current projects include controlling metal ion reduction kinetics and metal nanoparticle sizes using hydroxyl radical scavengers, controlling the composition of doped metal-oxide composite materials as CO2 hydrogenation catalysts, designing new one-step routes to metal-porous carbon nanomaterials, and depositing metal nanoparticles onto laser-induced periodic surface structures (LIPSS).

Ultrafast dissociation dynamics of polyatomic molecules

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, nitrotoluenes as models for nitroaromatic explosives, and drug compounds that are difficult to detect with traditional mass spectrometry methods.

---

Publications

Publications at VCU

Nanomaterials synthesis

K. E. Kay, L. M. Frisas Batista, K. M. Tibbetts, and J. K. Ferri, Stability of Uncapped Gold Nanoparticles Produced Via Laser Synthesis" Colloids Surf. A 2022 652 129860

L. M. Frisas Batista, A. Nag, V. K. Meader, and K. M. Tibbetts, "Generation of Nanomaterials by Reactive Laser Synthesis in Liquid", Sci. China Phys. Mech. Astron. 2022 65 1-45

L. M. Frias Batista, K. Kunzler, M. G. John, B. Clark, A. Bullock, J. Ferri, B. F. Gupton, and K. M. Tibbetts, “Laser Synthesis of Uncapped Palladium Nanocatalysts” Appl. Surf. Sci. 2021 557 149811

A. Nag, L. M. Frias Batista, and K. M. Tibbetts, “Synthesis of Air-Stable Cu Nanoparticles Using Laser Reduction in Liquid” Nanomaterials 2021 11 814

E. Broadhead, A. Monroe, and K. M. Tibbetts, “Deposition of Cubic Copper Nanoparticles on Silicon LIPSS via Reactive Laser Ablation in Liquid” Langmuir 2021 37 3740–3750

C. B. Nguyen, L. M. Frias Batista, M. G. John, C. J. Rodrigues, and K. M. Tibbetts, “Mechanism of Gold-Silver Alloy Nanoparticle Formation by Laser Co-Reduction of Gold and Silver Ions in Solution” J. Phys. Chem. B 2021 125 907-917

J. A. Bobb, C. J. Rodrigues, M. S. El-Shall, and K. M. Tibbetts, “Laser-assisted synthesis of gold-graphene oxide nanocomposites: Effect of pulse duration” Phys. Chem. Chem. Phys. 2020 22 18294-18303

E. Broadhead and K. M. Tibbetts, “Fabrication of Gold-Silicon Nanostructured Surfaces with Reactive Laser Ablation in Liquid” Langmuir 2020 36 10120-10129

M. G. John and K. M. Tibbetts, “Mechanism of Nickel Phyllosilicate Formation by Laser Ablation in Liquid”, J. Phys. Chem. C 2020 124 13273-13282

M. G. John and K. M. Tibbetts, “Controlling the morphology of copper-silica nanocomposites from laser ablation in liquid”, Appl. Surf. Sci. 2020 510 145037

L. M. Frias Batista, V. K. Meader, K. Romero, K. Kunzler, F. Kabir, A. Bullock, and K. M. Tibbetts, “Kinetic Control of [AuCl4]- Photochemical Reduction and Gold Nanoparticle Size with Hydroxyl Radical Scavengers”, J. Phys. Chem. B 2019 123 7204-7213

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

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

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

Ultrafast dissociation dynamics

V. Singh, H. A. López Peña, J. M. Shusterman, P. Vindel-Zandbergen, K. M. Tibbetts, and Spiridoula Matsika, “Conformer-Specific Dissociation Dynamics in Dimethyl Methylphosphonate Radical Cation”, Molecules 2022 27 2269

H. A. López Peña, J. M. Shusterman, D. Ampadu Boateng, K. U. Lao, and K. M. Tibbetts, “Coherent control of molecular dissociation by selective excitation of nuclear wave packets” Front. Chem. 2022 10 859095

M. D. Word, H. A. López Peña, D. Ampadu Boateng, S. L. McPherson, G. L. Gutsev, L. G. Gutsev, K. U. Lao, and K. M. Tibbetts, “Ultrafast Dynamics of Nitro-Nitrite Rearrangement and Dissociation in Nitromethane Cation”, J. Phys. Chem. A 2022 126 879-888

S. L. McPherson, J. M. Shusterman, H. A. López Peña, D. Ampadu Boateng, and K. M. Tibbetts, “Quantitative Analysis of Nitrotoluene Isomer Mixtures Using Femtosecond Time-Resolved Mass Spectrometry” Anal. Chem. 2021 93 11268-11274

H. A. López Peña, D. Ampadu Boateng, S. L. McPherson, and K. M. Tibbetts, “Using computational chemistry to design pump-probe schemes for measuring radical cation dynamics” Phys. Chem. Chem. Phys. 2021 23 13338-13348

G. L. Gutsev, S. L. McPherson, H. A. López Peña, D. Ampadu Boateng, L. G. Gutsev, B. R. Ramachandran, and K. M. Tibbetts, “Dissociation of Singly and Multiply Charged Nitromethane Cations: Femtosecond Laser Mass Spectrometry and Theoretical Modeling”, J. Phys. Chem. A 2020 124 7427-7438

G. L. Gutsev, H. A. López Peña, S. L. McPherson, D. Ampadu Boateng, B. R. Ramachandran, L. G. Gutsev, and K. M. Tibbetts, “From Neutral Aniline to Aniline Trication: A Computational and Experimental Study,” J. Phys. Chem. A 2020 124 3120-3134

K. M. Tibbetts, “Coherent vibrational and dissociation dynamics of polyatomic radical cations”, Chem. Eur. J. 2019 25, 8431-8439

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

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

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

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