BEGIN:VCALENDAR VERSION:2.0 PRODID:-//jEvents 2.0 for Joomla//EN CALSCALE:GREGORIAN METHOD:PUBLISH BEGIN:VEVENT UID:b719534f1ffc971b1d34a76efecc2e47 CATEGORIES:Physical Chemistry Seminar CREATED:20210226T181143 SUMMARY:Prof. Leah Dodson, University of Maryland DESCRIPTION:Cryogenic Spectroscopy of Molecular Ions: Applications and Future Astrochem ical Directions\nPreparation of cold (< 50 K) molecules and ions in the gas phase enables discoveries of the fundamental chemical and physical prop erties of these species. In this talk, I will show how we investigated the intrinsic photophysics of nitrophenolate isomers (meta, para, and ortho) at low temperature using photodissociation mass spectrometry in a cryogenic i on trap instrument. This study revealed that each isomer has distinct photo physics that affect the excited state lifetimes, as observed experimentally in their spectroscopic linewidths. Visible-light-induced excitation of m-n itrophenolate gives rise to well-resolved vibronic features in the spectrum of the S1 state that have been assigned using a Franck-Condon analysis. Th e para and ortho isomers have broad spectra – even at cryogenic temperature s – due to their shorter exited state lifetimes and spectral congestion. I will present computational evidence for mixing of the first and second exci ted states of o-nitrophenolate, leading to significant additional broadenin g in the experimental spectrum.\nI will also introduce the astrochemical go als of my new research group at the University of Maryland and describe how we will use similar low-temperature techniques to prepare and study molecu les and ions at temperatures relevant to circumstellar and planetary enviro nments.\nHosted by Professor Richard Remsing\nFor Webex meeting information , please contact Loretta Lupo @ (mailto:lal275@chem.rutgers.edu)This email address is being protected from spambots. You need JavaScript enabled to v iew it.\n X-ALT-DESC;FMTTYPE=text/html:
Cryogenic Spectroscopy of Molecular Ions : Applications and Future Astrochemical Directions
Preparation of cold (< 50 K) molecules and ions in the gas phase enables discoveries of the fundamental chemical and physical properties of these s pecies. In this talk, I will show how we investigated the intrinsic photoph ysics of nitrophenolate isomers (meta, para, and ortho ) at low temperature using photodissociation mass spectrometry in a cryogen ic ion trap instrument. This study revealed that each isomer has distinct p hotophysics that affect the excited state lifetimes, as observed experiment ally in their spectroscopic linewidths. Visible-light-induced excitation of m-nitrophenolate gives rise to well-resolved vibronic features in t he spectrum of the S1 state that have been assigned using a Franck-Condon a nalysis. The para and ortho isomers have broad spectra – even at cryogenic temperatures – due to their shorter exited state lifetimes an d spectral congestion. I will present computational evidence for mixing of the first and second excited states of o-nitrophenolate, leading to significant additional broadening in the experimental spectrum.
I will also introduce the astrochemical goals of my new research group at the University of Maryland and describe how we will use similar low-temp erature techniques to prepare and study molecules and ions at temperatures relevant to circumstellar and planetary environments.
Hosted by Professor Richard Remsing
For Webex meeting information,
please contact Loretta Lupo @