A recent study led by Zoltan Szakacs and Eric Vauthey from the University of Geneva explores excited-state symmetry breaking in donor-acceptor-donor systems. The associated paper just appeared in PCCP: Excited-state symmetry breaking in 9,10-dicyanoanthracene-based quadrupolar molecules: the effect of donor-acceptor branch length
The main idea behind this work is to use symmetry-selection rules and the associated forbidden transitions to probe how inversion symmetry is broken during the photodynamics. See [JPCL 2021, 12, 4067] for an initial discussion of the idea.