BisBF2 pyridoins: a new platform for the design of efficient two-photon absorbers

Abstract

We report the synthesis and photophysical studies of quadrupolar dyes based on a new core bearing two BF₂ moieties. Photophysical measurements showed the direct vs. via-spacer attachment of a strong donating substituent on the central core to playing a role in shifting the spectra but the same is critical for two-photon absorption cross-section. By comparing the obtained data, it was concluded that the direct attachment of the donor to the acceptor is not efficient to warrant the usefulness of dyes in bio-imaging. On the other hand, it was shown that for multi-photon absorption, introduction of the conjugated spacer in quadrupolar dyes is a more efficient way to increase the cross-section than the same for dipolar ones.