Copper-mediated phospha-annulation to attain water-soluble polycyclic luminophores

Abstract

A 6-membered P-heterocycle has been fused with a polyaromatic framework through intramolecular transformation of anthracene-based phosphine induced by CuCl₂. The resulting water soluble phosphonium fluorophores exhibit extremely high quantum efficiency along with prominent stability and low toxicity that make them suitable for one- and two-photon imaging purposes.