Triaryl Boron-Based A-π-A vs Triaryl Nitrogen-Based D-π-D Quadrupolar Compounds for Single- and Two-Photon Excited Fluorescence

Three new A-π-A-type compounds with trivalent boron, protected by two mesityl groups, as electron acceptor have been synthesized and investigated together with their two diphenylamino-ended D-π-D analogues. These boranes exhibit large two-photon absorption cross sections and high fluorescence quantum yields.