Breaking of symmetry of a molecular species by interactions with the solvent that
can
modify the molecular charge distribution, to favour asymmetrical configurations.
Note:
An example is the stabilization by a polar solvent of a light-induced charge
transfer state in a symmetric donor–acceptor–donor system.
Source:
PAC, 2007, 79, 293
(Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006))
on page 422