Ion pairs are ubiquitous in Nature, from sea water and aerosols, to living organisms. Being the very first step of crystallisation of ionic species and influencing the properties of ion-concentrated solutions or ionic liquids, they also play a key role in countless applications. Although they are met in many areas of Physics, Chemistry and Biology, their characterisation is complicated by the co-existence of several types of pairs and their elusive nature in solution. Research in this field gathers, so far, condensed phase experiments and theoretical studies, leaving the description of ion pairs at the microscopic level with rare experimental counterparts.
This project aims at documenting net neutral ion pairs at the atomic scale by investigating them in the gas phase using IR and UV laser spectroscopy combined with quantum chemistry calculations. For this purpose, we will develop a dedicated instrumental setup in order to reveal the intrinsic optical properties of ion pairs of each kind, which will lead, with the assistance of high level theoretical methods, to the characterisation of both their tridimensional structure and the interactions within the pair. We will apply this approach to a large variety of systems, from isolated to microsolvated, in a series of experiments where each ion pair or solvent molecule is added in a controlled way. We will target several basic questions from three different fields, demonstrating the potential interdisciplinary benefits of such a novel approach: the influence of nearby counterions on the structure of charged biomolecules, the ability of solvent molecules to dissociate an ion pair, and the early stages of ionic crystallisation will all be investigated at the microscopic level in an unprecedented way. It is expected that the advances resulting from such an original approach will advertise cold ion pairs as a great playground for gas phase physical-chemists, and will promote the construction of new bridges between scientific communities.
Monsieur Eric Gloaguen (Laboratoire Interactions Dynamiques et Lasers)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
LIDYL - CNRS IDF SUD Laboratoire Interactions Dynamiques et Lasers
Help of the ANR 294,425 euros
Beginning and duration of the scientific project: September 2016 - 48 Months