You are here

Barbara Marchetti, Ph. D.

Instructor of chemistry

Montgomery Hall, Room 218
P.O. Box 43700
Lafayette, LA 70504
barbara.marchetti1@louisiana.edu

 

Education:

  • 2016: Ph.D. Chemistry, University of Bristol, Bristol, UK. Advisor: Prof. Michael Ashfold. Thesis entitled: Gas-Phase Photochemistry of (Bio)Molecules and Metal Complexes
     
  • 2012: M.Sci. Chemistry with Honors, University of Perugia, Italy.

 

Professional Appointments:

(2018 – Present) University of Louisiana at Lafayette, Lafayette, U.S.A
Instructor of chemistry

(2017 – 2018) University of Pennsylvania, Philadelphia, U.S.A
Marie Skłodowska-Curie Research Fellow – Synthesis, spectroscopy and photochemistry of atmospherically relevant oxidants.

(2016 – 2017) Technical University of Munich, Munich, Germany
Technical University Foundation Fellow – Spectroscopic characterization and reactivity of homo-metallic size-selected sub-nanoclusters for heterogeneous catalysis

 

Research interests:

As well as teaching commitments, I also run an active research group. My research involves experimental studies of the spectroscopy and photochemistry of (bio)molecules in bulk complex environments. We are particularly interested in the ultrafast and long-timescale dynamics of electronically excited chromophores and how such processes apply to atmospheric and biological systems.

Our ongoing research projects are reported below.

  1. Photochemistry of simple aromatic and heteroaromatic molecules. Spectral evolution and kinetics of photoirradiation of aromatic and heteroaromatic building blocks can be acquired at different excitation wavelengths using our set-up: the studies are aimed at exploring how well the organic molecules cope with prolonged exposure to UV-Vis light. Deep insights into the mechanism of photoreactions (including the role of the solvent) are provided by computation of reaction pathways.
     
  2. Synthesis and characterization of new sunscreen prototypes. The project is an extension of previous studies and is carried out in collaboration with the synthetic organic chemistry group (Dr. Gallo) and computational chemistry group (Dr. Karsili). The project relies on the synthesis of new compounds from naturally occurring precursors. Such compounds are carefully tailored to be highly stable under sustained and prolonged UV-Vis irradiation, in order to be  potential candidates as active ingredients in sunscreen formulations. Spectroscopic characterization of the synthesized molecules are carried out prior photoirradiation studies to test photostability.  The effects of solvent, temperature and chemical substitution on the photostability of the prototypes are also explored. As a last step, the effect of synergistic photostability-enhancing compounds, such as radical scavengers and excited state quenchers, is also a central part of this project.
     
  3. Photo-oxidative potential of dissolved organic matter in the coastal environments of Louisiana. Dissolved organic matter (DOM) is a highly composite mixture of organic materials found in water environments. They mostly derive from the decay of organic tissues.  DOM has vital importance for recycling of essential nutrients as well as participating in the transport and reactivity of many organic components dissolved in rivers, basins and sea waters. An important sub-set of such reactions include the production of extremely reactive intermediates (e.g. singlet oxygen and hydroxyl radicals) following absorption of UV-Vis light on ocean surfaces and estuarian waters. We aim at investigating the photochemical and photophysical processes involved in the photoexcitation of DOM and/or its various components in pure water and saline solutions, including their dependence on the irradiation wavelengths and chemical environment on the photochemistry of DOM.
     
  4. Photodynamic therapy via organometallic complex sensitization. Organometallic complexes have been at the focus of chemical research in the past decades for their pronounced ability of facilitating chemical reactions. Here, our focus is on the ways in which organometallic compounds promote the formation of singlet oxygen via sensitization. The ultimate goal is the development of efficient light activated prodrugs for the effective damage of DNA and protein structures - which may then be used in future cancer therapy. In this project, we collaborate with the group of Dr. Radhey Srivastava who are experts on the synthesis of highly chiral and ordered organometallic frameworks for asymmetric catalysis.

 

Awarded grants:

  1. Marie-Skłodowska-Curie Global Post-Doctoral Fellowship. PhARRAO: Photo- and Radical- induced Reactivity of Atmospheric Oxidants. 2016. Grant Amount: $280,000.
     
  2. Technical University of Munich Foundation Fellowship. 2016. Grant Amount: 35,000 Euros.

 

Latest publications:

  1. M. F. Vansco, B. Marchetti, T. Bhagde, G. Wang, N. Trongsiriwat, P. J. Walsh, S. J. Klippenstein, and Marsha I. Lester, Synthesis, Electronic Spectroscopy, and Photochemistry of Methacrolein Oxide: A Four-Carbon Unsaturated Criegee Intermediate from Isoprene Ozonolysis, J. Am. Chem. Soc,, 2019, 141, 15058.
     
  2. B. Marchetti, T. N. V. Karsili and M. N. R. Ashfold, Exploring Norrish Type I and Type II Reactions: An ab initio Mechanistic Study Highlighting Singlet- State Mediated chemistry, Phys. Chem. Chem. Phys., 2019, 21, 14418.
     
  3. M. F. Vansco, B. Marchetti and M. I. Lester, Electronic spectroscopy of methyl vinyl ketone oxide: A four-carbon unsaturated Criegee intermediate from isoprene ozonolysis, J. Chem. Phys., 2018, 149, 244309.
     
  4. B. Marchetti, T. N. V. Karsili and M. N. R. Ashfold, The Role of ps* States in the Formation of Adenine Radical-Cations in DNA Duplexes, Chemical Physics, 2018, 515, 464.
     
  5. P. Chakraborty, T. N. V. Karsili, B. Marchetti and S. Matsika, Mechanistic insights into photoinduced damage of DNA and RNA nucleobases in the gas phase and in bulk solution, Faraday Discussions, 2018, 207, 329.

For the full list of publication click here