Continetti, Robert
Dissociation dynamics of transient species, three-body reaction dynamics, aerosol and ice grain chemistry, and novel mass-spectrometric methods

Contact Information
Distinguished Professor of Chemistry and Biochemistry
Senior Associate Vice Chancellor - Academic Affairs

Office: Urey Hall Addn 3020E
Phone: 858-534-5559
Group: View group members
1989 Ph.D., University of California, Berkeley
1983 B.A., Johns Hopkins University
2018 Sr. Associate Vice Chancellor Academic Affairs, UC San Diego
2015 Distinguished Professor, UC San Diego
2013 Professore Visitatore, University of Rome La Sapienza
2012 Wilsmore Fellow, University of Melbourne
2006-2012 Department Chair, UC San Diego
2006-2011 Kurt Shuler Scholar, UC San Diego
1999 Professor, UC San Diego
1997 Assoc. Professor, UC San Diego
1992 Asst. Professor, UC San Diego
1989 Postdoc, University of California, Berkeley
Awards and Academic Honors
Fellow, American Association for the Advancement of Science
UCSD Diversity Champion Award
ACS Division of Physical Chemistry Award in Experimental Chemistry
Fellow, American Physical Society
Alfred P. Sloan Research Fellowship
Camille Dreyfus Teacher-Scholar Award
David and Lucile Packard Fellowship in Sciences and Engineering
Camille and Henry Dreyfus New Faculty Award
Research Interests
Our laboratory studies chemical phenomena ranging from the dynamics of isolated molecular ions and radicals to aqueous kinetics in micron-sized droplets.

The traditional focus of the lab has been on studies of the transient species, including reactive free radicals and molecular clusters, that play central roles in governing the chemical behavior of complex systems. We characterize these species by using a variety of techniques, including mass spectrometry, photoelectron and photofragment spectroscopies and the measurement of scattering cross-sections. These experiments provide critical tests of modern electronic structure and dynamics calculations, and in the case of three-body dissociation, new types of experimental data on the dynamics of these processes.

Our studies of reactive free-radicals, transition-states and multi-body dissociation dynamics use the photoelectron-photofragment coincidence technique developed here. These experiments are carried out using fast, mass-selected anion beams with short-pulse tunable laser photodetachment. The photoelectron kinetic energy and angle of recoil is measured using imaging techniques, which determines the internal energy in the neutral molecule or cluster under study. If the neutral is unstable and dissociates, then the kinetic energy and angular distributions of the products are recorded using time- and position-sensitive detectors. Analysis of these experiments is carried out in conjunction with ab initio electronic structure, Franck-Condon and dynamics calculations. These techniques are applied to studies of reactive organic intermediates and the dynamics of hydroxyl radical reactions important in combustion and atmospheric processes. Another important research focus has been on decarboxylation dynamics of carboxylate anions and radicals in increasingly complex systems prepared using electrospray ionization.

In recent years we have developed a research thrust in the area of the spectroscopy and dynamics of aqueous aerosol droplets and the impact dynamics of sub- and micron-sized particles and ice grains. These experiments in the former case use a controlled-atmosphere electrodynamic balance instrumented with Mie scattering for the determination of particle phase and Raman spectroscopy for studying the chemical composition of aerosols undergoing chemical transformation. Our studies in the latter case are carried out using a unique apparatus we have constructed, the Aerosol Impact Spectrometer. This apparatus will makes use of electrospray ionization, charge detection mass spectrometry and a linear accelerator to measure the mass and charge of individual particles, and then accelerate or decelerate them to study the impact dynamics on various targets using image-charge-based detectors as well as impact-induced ionization time-of-flight mass spectrometry. With this apparatus we have studies the impact dynamics of tin particles and ice grains, and are now carrying out studies of ice grain impacts over a wide velocity range to understand the fragmentation of molecules in hypervelocity impacts and to learn about chemical gradients in ice grains.
Primary Research Area
Physical/Analytical Chemistry
Interdisciplinary interests
Atmospheric and Environmental
Physical Organic

Image Gallery

Experiment and Theory for the Benchmark Reaction F + H2O -> HF + OH

Selected Publications