Synthesis of functionalized ethynylphenothiazine fluorophores.

ABSTRACT

Alkynylated and butadiynyl-bridged phenothiazines with variable functionalization can be synthesized in good yields by cross-coupling and condensation approaches. In addition, the structure of the diethynylated phenothiazine (7a) has been corroborated by an X-ray structure analysis. These oligofunctional heterocycles are fluorescent with modest quantum yields (Phi(f) = 20-35%) and represent suitable building blocks for novel photoexcitable molecular wires.