External Pressure in Conceptual Density Functional Theory: Molecular Reactivity and Electronic Structure via the Extreme Pressure Polarizable Continuum Model.

While the influence of pressure on physical and chemical properties
of substances has been the subject of long-standing interest in
chemistry, scrutinizing molecular behavior at extreme pressures has
spiked in recent years. A scientific knowledge gap, however, is still
present on how and why chemistry at the molecular level under high
pressure is different from that at ambient conditions. The global aim
of the research project involves the study of the effect of external
pressure on chemical reactivity as probed through the recently
introduced XP-PCM model and Density Functional Theory based
reactivity indices. Incorporating the effect of pressure into this
framework through the Pauli potential should allow for a better
understanding of the difference between purely electronic effects and
the influence of the volume. Starting from recent results on atomic
systems, small molecules will serve as a first guide in the exploration
of pressure as an external perturbation of the response functions.
Then, the regioselectivity of the Diels-Alder reaction will be probed
and the effects of pressure on the aromaticity of the transition state
will be examined for the first time. Finally, the obtained knowledge
will be implemented in the design of pressure-induced molecular
switches based on expanded porphyrins.