One-Pot Synthesis of π-Extended Fluorenone-Fused Subphthalocyanines.

A family of inherently chiral nonplanar aromatic chromophores, comprising Subphthalocyanines bearing fluorenone-fused units (SubFcs), have been prepared by an innovative one-pot synthesis, which relies on the standard cross-cyclotrimerization of phthalonitriles followed by intramolecular Friedel-Crafts acylation. Their Q-band absorption experiences a ca. 20 nm red shift per fused fluorenone as a consequence of the enlarged conjugated π-system.