Using Photostability to Help Select Life

Speaker: Gregory Gate, UCSB 

Program Description:
The canonical nucleobases, shared by all life today, have very unique photostability properties. They exhibit UV light hardiness, not shared by most nucleobase analogues, suggesting a photochemical selection occured four billion years ago, when life was first arising. Conducting jet-cooled multiphoton ionization with various double resonant and pump-probe methods provides us with isomer selective spectroscopy in the picosecond time domain. These experiments let us map the relevant mechanisms that dissipate the photon energy following UV absorption. A picture emerges of complex excited state dynamics of nucleobases with subtle dependence on molecular structure.