Research Highlights
Nature Chemistry: Collisional Alignment and Molecular Rotation Control the Chemi-ionization
of Individual Conformers of Hydroquinone with Metastable Neon
A newly published review article has recently been published in Nature Chemistry coauthored by Dr. Jesus Pérez-Ríos! In this work, Dr. Pérez-Ríos and his collaborators
focus on a central tenet in chemistry: the relationship between the shape of a molecule
and its chemical reactivity.
Chemi-ionization (CI) reactions are important in plasmas, planetary atmospheres and interstellar space, reactive collisions with quantum effects, and other energetic environments. In this study, the authors deployed an experiment utilizing electrostatic deflection to separate individual conformers of 1,4-dihydroxybenzene (hydroquinone, HYQ) within a molecular beam. These conformers differ by a single bond rotation (as shown in the figure below), which leads to different dipole moments. These are intersected with another beam containing metastable neon atoms in the excited (2p)5(3s)13P2,0 states (Ne* ) that ionize the molecular collision partner.
Schematic of the setup and geometries of the polar cis- and apolar trans-HYQ. Differences
in effective dipole moment between the two conformers lead to spatial separation after
passing through the electrostatic deflector.
Nature Astronomy: Free-floating Binary Planets from Ejections During Close Stellar
Encounters
Exoplanets -- planets beyond our solar system -- have been found in increasing amounts
over the years as our telescope techonology continues to improve. However, a number
of exoplanets about the same size of Jupiter have been found in pairs, floating together
through space with no host star to orbit around. These types of systems have been
dubbed JuMBOs, or Jupiter-Mass Binary Objects. Recently, Dr. Rosalba Perna and collaborators
have developed a theory to help explain the mysterious prevalence of the JuMBOs scattered
throughout the galaxy!
The key of this new theory lies in close fly-bys between two stars. One star is host
to the two Jupiter-size exoplanets, and when the second star gets close enough, the
two planets can be ejected out of their original host star's influence.
A sketch method through which JuMBOs are produced. On the left, we see the schematic
of the mechanism developed. Host star M1 has the two Jupiter-size exoplanets, marked by the blue dots. A fly-by of star M2 then causes these planets to be ejected out of the system together. The diagram on
the right shows the various variables needed to work out the theory's mathematical
details, such as the various orbit angles and the interloping star's velocity.
Nature Physics: Ultracold Chemistry as a Testbed for Few-body Physics
Dr. Jesus Pérez-Ríos and collaborators have recently published a new review article
in Nature Physics! With it, they seek to give insight into how cold systems with only a few particles
can serve as a unique tool to explore chemistry in these environments!
The potential of these systems span a broad range of interesting applications, from quantum computing to highly detailed study of chemical reactions. For example, ultracold studies provide access to behaviors at a quantum mechanical level, allowing researchers the ability to carefully prepare the molecules to control their chemical behaviors and reactivities! With temperatures as low as a few microkelvin (less than -400 °F), these molecules are incredibly cold. However, the interactions that they participate in can have energies thousands of times larger than that!
A diagram depicting the relevant energy scales and distances for these ultracold interactions.
a) A zoomed in view of the peak, showing how close the various rotational and vibrational
energy states are separated. b) Energy interactions on a longer distance scale, showing
that the overall large-scale interactions have behaviors more aligned with the small
scale energy differences, as opposed to the short-scale strong interactions.
Research Groups and Connected Research Centers