While early investigations in two-photon absorption (TPA) mainly focused on developing structure/property
relationships for organic molecules with a conjugated path extending in one dimension, more recent research efforts
have also included molecules containing multiple TPA-active units or with multi-dimensional conjugated backbones.
However, a complete understanding of how the number and structure of branches in chromophores affect TPA properties
has not yet emerged. Here, we describe chromophores consisting of four donor-substituted branches linked to an
aromatic core (benzene or pyrazine) and compare them with linear analogues with only two branches (donor-Π-donor
distryrylbenzenes). It is shown that this design does not lead to large enhancement of the TPA cross sections, with only
a modest increase being observed going from compounds with two to compounds with four branches. It is also shown
that a molecular exciton model can describe semi-quantitatively both the one-photon and the two-photon spectra of this
type of multi-branched compounds. In contrast to the one-photon case, the model shows that pure additivity of the TPA
cross section should not, in general, be expected when two monomer units are coupled, and that the TPA cross section of
the composite molecule depends on the relative orientation of the constituent units and on the strength and sign of the
coupling interaction.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.