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
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!
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.
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!
Last week Craig and Sara traveled to Chicago for the 10th International Conference on Chemical Kinetics hosted by the University of Illinois at Chicago. This 4-day conference featured talks from many different areas of research including pyrolysis, catalysis, and atmospheric chemistry.
Sara presented a poster on the reactions of the simplest Criegee intermediate with inorganic acids and alcohols:
They also had many opportunities to try the fantastic food Chicago has to offer, and highly recommend the cheeseburger with egg and bacon at Au Cheval.
They also visited The Bean!
Many congratulations to Liz, whose work has been recognized with the award of the E.K.C. Lee Fellowship. The Lee Fellowship is named after Prof. Ed Lee, one of the department’s founding faculty members and is awarded “to support outstanding students in chemistry.”
Our latest paper, exploring the photochemistry of acetaldehyde to form CH3 + HCO across a broad range of wavelengths, has been published in PCCP. We used a combination of time-resolved ion imaging, with nanosecond and picosecond pulsed lasers, and photofragment excitation action spectroscopy to identify three distinct dissociation mechanisms. At long wavelengths, dissociation occurs statistically on the S0 surface after many tens of nanoseconds. Dissociation at intermediate wavelengths is dominated by relatively fast dissociation on the T1 surface, leading to fast-moving CH3 radicals. At short wavelengths, a new pathway opens that is assigned to dissociation on the S0 surface, accessed via a conical intersection.
The article can be accessed here: 10.1039/c7cp02573d
Our building, Rowland Hall, was dedicated as a National Historic Chemical Landmark by the ACS on April 18th, in recognition of the Nobel Prize-winning work performed there by Sherry Rowland and Mario Molina that identified the role of chlorofluorocarbons in stratospheric ozone loss. A two-day symposium was held at the Beckman Center on April 18th–19th to mark the occasion, featuring distinguished guest speakers from academia, and local AirUCI contributions. Kara and Saswata Roy from Prof. Filipp Furche’s group gave a great joint TED-style presentation explaining how a combination of experiment and theory can provide insights into molecular photochemistry.
On May 12th, we attended the 34th Informal Symposium on Kinetics and Photochemical Processes in the Atmosphere held at UCSD. I gave a talk describing some of our work on the reactions of Criegee intermediates with trace atmospheric gases, Sara presented a poster on the same, and Kara
loitered networked. Aside from learning some exciting new science, we also discovered that the tacos at Puesto in La Jolla are excellent.
Finally, we bade a fond farewell to Ben who has moved on to pastures new. This month he begins a post-doctoral position at Lawrence Berkeley National Lab, working with Dr. Oliver Gessner and Prof. Steve Leone in the Ultrafast X-Ray Science Laboratory. We wish him all the best in the Bay Area and have no doubt that he will be tremendously successful there.
Last week Craig, Kara, and Liz traveled to Asilomar, CA to attend the Pacific Conference on Spectroscopy and Dynamics 2017. Luck was on our side and we were not swept away by a tsunami or mudslide!
In the poster sessions Craig and Kara presented “Competing Pathways in the Near-UV Photochemistry of Acetaldehyde” and “UV photodissociation dynamics of CHI2Cl and its role as a photolytic precursor for a chlorinated Criegee intermediate”.
Liz presented a talk entitled “Direct Kinetics Measurements and Atmospheric Implications of the Reactions between Criegee Intermediates and Tropospheric Pollutants”.