Alexander Aster, Giuseppe Licari, Francesco Zinna, Elodie Brun, Tatu
Kumpulainen, Emad Tajkhorshid, Jerome Lacour, and Eric Vauthey.
Tuning symmetry breaking charge separation in perylene bichromophores
by conformational control.
Chemical Science, 10:10629-10639, 2019.
ASTE2019-ET
Understanding structure-property relationships in multichromophoric molecular
architectures is a crucial step in establishing new design principles in organic
electronics as well as to fully understand how nature exploits solar energy. Here, we
study the excited state dynamics of three bichromophores consisting of two perylene
chromophores linked to three different crown-ether backbones, using stationary and
ultrafast electronic spectroscopy combined with molecular dynamics simulations. The
conformational space available to the bichromophores depends on the structure and
geometry of the crown-ether and can be significantly changed upon cation binding,
strongly affecting the excited-state dynamics. We show that, depending on the
conformational restrictions and the local environment, the nature of the excited state
varies greatly, going from an excimer to a symmetry-broken charge separated state.
These results can be rationalised in terms of a structure-property relationship that
includes the effect of the local environment.
