91AV

The quantum mechanical properties of small molecules provide the basis for our quantitative understanding of chemistry and a testing ground for new theories of molecular structure and reactivity. With modern methods, small molecular systems can be investigated in extraordinary detail by high-resolution spectroscopic techniques in the frequency or the time domains, and by complementary theoretical and computational advances. This combination of cutting-edge approaches provides rigorous tests of our understanding of quantum phenomena in chemistry. The chemical properties of small molecules continue to present rich challenges at the chemistry/physics interface since these molecules exhibit properties in isolation, and interact with their environments, in ways that are not yet fully understood. The coupled electronic and nuclear motions may lead to complex structural or dynamical features that can now be observed experimentally. From a theoretical point of view, these features can only be explained if the quantum nature of the atomic nuclei is considered together with the possible couplings between nuclear and electronic degrees of freedom.
 
New developments, from both the theoretical and experimental side, are urgently needed if the properties of small molecules are to be optimally exploited in future technological, engineering and biological applications of outstanding importance.
 
This Faraday Discussion will address the quantum dynamical properties of small molecules, both in isolation where extraordinarily detailed and precise measurements and calculations are now emerging, and when embedded in complex media such as molecular clusters, quantum fluids and bulk liquids.
 
The Discussion will appeal to researchers working on both isolated and confined molecular systems.
The topics selected for discussion are fundamental in nature, but will have broader impacts in many fields: examples include atmospheric chemistry (e.g., properties and fates of reactive intermediates and long-lived greenhouse gases), biology (e.g. gaseous signalling molecules such as NO, H₂S and their bioactive products), physics (e.g., multi-charged molecular ions, cold matter, plasmas, quantum technologies, and high temperature and pressure processes), and astrophysics and astrochemistry (e.g., cold collisions, reaction mechanisms, and the formation of prebiotic molecules).
 

Format

The Faraday Division have been organising high impact Faraday Discussions in rapidly developing areas of the physical sciences, with a focus on physical chemistry and its interfaces with other scientific disciplines for over 100 years.
Faraday Discussions have a special format where research papers written by the speakers are distributed to all participants before the meeting, and most of the meeting is devoted to discussing the papers. Everyone contributes to the discussion - including presenting their own relevant research. The research papers and a record of the discussion are published in the journal Faraday Discussions.
   

Aims

This meeting aims to gather key participants representing the full scientific scope of the topic, conducting a deep and critical discussion on the spectroscopy and the reactivity of small molecular systems, which will pave the way for new theoretical insights and applications in wider areas. The event will help participants and the community to identify new and still unresolved challenges in the molecular sciences. The focus will be on small molecule chemical physics, which is essential for a deep understanding of the impact of quantum dynamics on these wider fields.

Themes

Precise Characterisation of Isolated Molecules
This session will present the latest developments in the field of precise characterization and study of isolated small molecular systems. The emphasis will be on exotic species, including molecules in electronic states located close to dissociation limits or to ionization.
 
Quantum Dynamics of Isolated Molecules
This session will focus on the quantum nature of electronic and nuclear motions in isolated molecules, their interplay, and their observation and control by advanced laser techniques. We will welcome contributions that offer new advances in the investigation of quantum localization.
 
Molecules in Confinement in Liquid Solvents
This session will examine how the properties of small molecules are modified by immersion in a liquid solvent. Recent theoretical and experimental developments have highlighted the importance of considering solute-solvent interactions explicitly at the atomic level. The interactions can be long or short range, and can be directional, as for example with hydrogen bonding. They modify ground and excited potential energy surfaces, the non-adiabatic interactions between electronic states, and consequently the nuclear dynamics of molecules undergoing chemical change.
 
Molecules in Confinement in Clusters, Quantum Solvents and Matrices
This session will focus on isolated molecules confined by a surrounding medium which has pronounced quantum mechanical character. Examples include molecular clusters, quantum solvents (e.g. superfluid He droplets) and frozen solid matrices (e.g. of p-H₂), and adsorption at nanostructures. In these quantum environments, unexpected effects have been observed on the properties and dynamics of small solute molecules, which remain to be fully explored and understood.

Poster Prize Winner

Low-energy electron transport in confined systems: From clusters to bulk
Loren Ban, ETH Zurich, Switzerland