CCE Newsletter Winter 2023

Welcome Message from the Chair, Dennis Dougherty

This issue of our Winter newsletter covers quite a bit activity from the last few months. We highlight just some of our divisional events like the biannual Safety Day, the return of the traditional CCE Golf Tournament, and National Chemistry Week. We also highlight some of the major awards and honors received by CCE members as well as some of the cutting edge research conducted here. This quarter, we meet a couple of new members of the division including our new machinist and new Senior Director of Development. We continued our Institute-leading work in DEI with a joint winter social hosted by DICI, WiC and the CGSC. Finally, the highlight of our newsletter is coverage of the Inaugural Peter Dervan Lecture presented by Nobel Laureate Jennifer Doudna. As CCE continues its tradition of excellence I would love to hear your thoughts via email to cce@caltech.edu.

Chan Lab

"New theory explains magnetic trends in high-temperature superconductors"

In a field where scientists have not yet figured out how cuprate superconductors work, researchers in the Chan Lab have developed a theory that explains some of their magnetic properties.

In a paper titled "Systematic electronic structure in the cuprate parent state from quantum many-body simulations", published in the journal Science, Professor Garnet Chan and his coauthors explain how the magnetic layer effect arises from fluctuations of the electrons between the copper and oxygen atoms and their surrounding atoms.

Nelson Lab

"Taking inspiration from nature to make molecules like nature does"

In a paper titled "Catalytic asymmetric C–H insertion reactions of vinyl carbocations" published in the journal Science, Professor Hosea Nelson describes a new technique devised in his lab that allows for the precise selection of molecular handedness in chemical reactions.

Robb Lab

"A Rainbow of Force-Activated Pigments"

Professor Maxwell Robb has been working to make stress easier to identify through the creation of polymers that change color when a force is applied to them. In a paper published in Nature Chemistry titled "Mechanically gated formation of donor– acceptor Stenhouse adducts enabling mechanochemical multicolour soft lithography", Robb shows how his team created a new type of these polymers that can be made to change to almost any colors the user wants. This is in contrast to the polymers he had previously developed, which could only change to a single, predetermined color.

Ismagilov Lab

Extreme differences in SARS-CoV-2 viral loads among respiratory specimen types during presumed pre-infectious and infectious periods

In a longitudinal study of SARS-CoV-2 Omicron viral loads in three paired specimen types (saliva, anterior-nares swabs, and oropharyngeal swabs), the Ismagilov lab found extreme differences among paired specimen types collected from a person at the same timepoint, and that viral loads in different specimen types from the same person often do not correlate throughout infection. Individuals often exhibited high, presumably infectious viral loads in oral specimen types before nasal viral loads remained low or even undetectable. Combination oropharyngeal-nasal swabs were inferred to have superior clinical sensitivity to detect infected and infectious individuals. This demonstrates that single specimen type reference standard tests for SARS-CoV-2, such as in clinical trials or diagnostics evaluations, may miss infected and even infectious individuals.

Peters Lab

"Catalytic transfer hydrogenation of N2 to NH3 via a photoredox catalysis strategy"

Any effort to “decarbonize” the world’s economies will need to come to grips with finding new ways to make ammonia—a substance essential to agricultural fertilizers,

The Peters lab now reports an advance in one such alternative approach—using light to drive the chemical reduction of atmospheric nitrogen that lies at the heart of ammonia production. The finding, stresses research team leader Jonas Peters, is still at the “fundamental science” stage, and not ready for direct application, however it does offer interesting progress toward more sustainable production of an indispensable material as the world grapples with climate change.