New NSF award to study Criegee intermediate reactivity

We have been awarded $394,638 by the Chemistry Division of the National Science Foundation for a three-year project titled, “Kinetic and Mechanistic Studies of Criegee Intermediate reactivity.” The project is part of the Environmental Chemical Sciences program. We will use laser flash photolysis and broadband transient absorption spectroscopy to measure temperature-dependent rate constants of Criegee intermediate reactions with trace atmospheric gases. Specifically, we will study Criegee intermediate reactions with multifunctional volatile organic compounds, radical species, and explore the influence of humidity on reactivity. A new outreach program will establish air quality and weather monitoring stations at local high schools.

Summer 2019 research opportunity for high school teachers

An opportunity is available for a high school chemistry teacher to participate in summer research in Dr. Craig Murray’s laboratory in the Department of Chemistry at the University of California, Irvine (UCI). The Murray Group uses a variety of laser-based spectroscopic techniques to study fundamental photochemistry and reaction kinetics and has a particular interest in processes relevant to atmospheric chemistry. The ‘Teacher-in-Residence’ program comprises two parts:

  • Four-week summer research. You will work directly with Dr. Murray and his research group in the laboratory and participate in other research-related activities to obtain direct experience of an academic research environment. The scheduling can be flexible to work around other commitments (e.g. weeks need not be consecutive).
  • Class visit. You will bring your students (limited to 30 total visitors) to campus for a day. We will provide tours of various research laboratories and host a symposium to discuss research, educational opportunities at UCI, and current issues in environmental and atmospheric chemistry.

The ‘Teacher-in-Residence’ program is funded through an NSF award (CHE-1566064). Participants will receive a modest stipend during the summer and costs associated with the class visit will be covered. If you are interested in participating and experiencing a real academic research environment, or have any questions about the program, please contact Craig Murray (craig.murray@uci.edu) directly before May 10, 2019.

Acetaldehyde cation photofragmentation paper published in PCCP


We explore the UV photofragmentation dynamics of acetaldehyde cation in our latest paper published in PCCP. Single-photon VUV ionization was used to prepare cold acetaldehyde cations that are subsequently excited (and fragmented) by UV radiation. The photochemistry is surprisingly rich; we use velocity-map ion imaging to characterize four different photofragmentation channels across a broad range of wavelengths. The experiments are supported by complementary ab initio calculations. The article will appear in a special themed issue of PCCP on Photodissociation and Reaction Dynamics that will be published to celebrate the 65th birthday of former University of Bristol colleague Prof. Mike Ashfold.

You can read the paper here: 10.1039/c8cp06640j

Acetone photodissociation paper appears in PCCP

Our latest photodissociation dynamics paper has been published in PCCP. The new paper describes ion imaging and photofragment excitation spectroscopy experiments exploring the photochemistry of acetone. We identify ketene as a new primary photoproduct following excitation to S1 and suggest that a roaming mechanism may be responsible. The radical channel forming methyl and acetyl is characterized over a broad range of wavelengths and is dominated by dissociation on the T1 surface following intersystem crossing. Time-resolved measurements using a ps laser system at 266 nm, find an intersystem crossing rate that is surprisingly around six times slower than in acetaldehyde.

You can read the paper here: 10.1039/c7cp07320h

New Criegee paper in JPCA

Our new paper published in J. Phys. Chem. A. combines broadband transient absorption spectroscopy with complementary ab initio calculations to explore the kinetics of the reactions of the simplest Criegee intermediate with a series of alcohols. The results of this study provide new insights into trends in Criegee reactivity.

You can read the paper here: 10.1021/acs.jpca.7b09773

New imaging paper published in PCCP

Our most recent paper published in Phys. Chem. Chem. Phys. explores the photochemistry of chlorodiiodomethane (CHI2Cl), a precursor of chlorinated Criegee intermediates.  Velocity map ion imaging experiments and high-level ab initio calculations were employed to characterize the photodissociation dynamics of CHI2Cl over a range of wavelengths.  We further used transient absorption spectroscopy to measure the UV absorption spectrum of a chlorinated Criegee intermediate, ClCHOO, produced from the reaction of CHICl with O2.

Check out our paper here: 10.1039/C7CP06532A

This article was selected as part of the 2017 PCCP HOT Articles themed collection.

Liz defends… and departs

Congratulations to Liz, who successfully defended her PhD dissertation last week despite the best efforts of an antique laptop to derail her talk. The defense was concluded with the conferral of her ceremonial tool belt. It was also great to see Ben again, who belatedly received his. We also said farewell to Liz this week. Liz moves to New England, where she will begin a post-doctoral position at MIT, working with Profs. Bob Field and Christopher Cummins. We wish her every success in her new job!

Teachers join lab

We are delighted to welcome high school teachers Larry Sepulveda (Rosemead High School) and Linda Kazibwe-James (Whittier Christian School) to the group. Larry and Linda are participating in our NSF-funded ‘Teacher in Residence’ outreach program this year, and will be working with us in the lab for the next month. The program aims to provide high school teachers with hands-on experience of life in a research laboratory.

Liz gets hooded!

Last Saturday, Liz was hooded by Craig as a (soon-to-be) Doctor of Philosophy! The ceremony was held at the Bren Events Center and honored the hard work and achievements of the class of 2017. Craig did a great job with the hooding (no hats were knocked off!) and everyone’s efforts were rewarded with a champagne reception following the event.

Craig, Liz, and Dean Janda

Unofficially an official PhD!

Liz gives the experience two thumbs up!