Abstract
Photoelectron spectroscopy of microjets expanded into vacuum allows access to orbital energies for solute or solvent molecules in the liquid phase. Microjets of water, acetonitrile and alcohols have previously been studied; however, it has been unclear whether jets of low temperature molecular solvents could be realized. Here we demonstrate a stable 20 μm jet of liquid ammonia (−60 °C) in a vacuum, which we use to record both valence and core-level band photoelectron spectra using soft X-ray synchrotron radiation. Significant shifts from isolated ammonia in the gas-phase are observed, as is the liquid-phase photoelectron angular anisotropy. Comparisons with spectra of ammonia in clusters and the solid phase, as well as spectra for water in various phases potentially reveal how hydrogen bonding is reflected in the condensed phase electronic structure.
Highlights
Liquid ammonia is often used as a medium for organic chemistry due its ability to support long-lived highly reducing solvated electrons, first demonstrated by Birch in 1944.1 Solvated electrons can be generated by adding an alkali metal to anhydrous liquid ammonia; the solvated electrons have lifetimes on the order of months for solutions which are free from oxygen and moisture
A further interest in the liquid ammonia photoelectron spectrum is the comparison of the two simplest hydrogen bonded liquids: the question of how electronic structure evolves from isolated molecular H2O or NH3 through molecular clusters all the way to liquid, and the effect of hydrogen bond strength on the orbital binding energies
A prerequisite to progress on the electronic structure of NH3(aq) is to demonstrate the generation of a stable liquid jet of ammonia to enable photoelectron studies in vacuum
Summary
Communication introduced into the head space of the sample cylinder to force the liquid ammonia through 6 mm dimeter steel tubing to a 20 μm diameter nozzle by pressurization (5 bar), keeping the line at the same temperature until reaching the beginning of the glass jet nozzle. PE experiments were carried out with the SOL3PES experimental setup[14] at the variable polarization UE52-SGM1 beamline at the synchrotron radiation facility BESSY II.[15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
