Synthesis of seminaphtho-phospha-fluorescein dyes based on the consecutive arylation of aryldichlorophosphines.

Seminaphtho-phospha-fluorescein (SNAPF), a phosphine-oxide-containing unsymmetric fluorescein dye, was synthesized based on the consecutive arylation of PhPCl, followed by Friedel-Crafts cyclization. The resulting SNAPF exhibited several attractive photophysical properties including an intense fluorescence in the NIR region and a large Stokes shift.

Tuning the Photophysical Properties of Photostable Benzo[b]phosphole P-Oxide-Based Fluorophores.

We previously reported that constrained 2-phenylbenzo[b]phosphole P-oxides bearing a diphenylamino group show high photostability and thus are promising dyes for fluorescence imaging. Herein we investigated the impact of the bridging moieties on their photophysical properties. A series of benzo[b]phosphole P-oxides constrained with various carbon or silicon bridges were synthesized.