Heteroatom-Connected Ferrocenyl BODIPYs: Synthesis, Structure, and Properties

Abstract

The set of heteroatom-connected ferrocenyl BODIPYs <b>2a</b>,<b>b</b> and <b>3c</b>,<b>d</b> were designed and synthesized by the nucleophilic aromatic substitution reaction of 8-chloro BODIPY <b>1</b>, with ferrocenyl anilines and ferrocenyl phenols. The effects of a heteroatom at the <i>meso</i> position on the optical and electrochemical properties of the BODIPYs were studied. The absorption spectra of the BODIPYs containing an N atom at the <i>meso</i> position (<b>2a</b>,<b>b</b>) show a blue shift of 80 nm, whereas the BODIPYs containing an O atom at the <i>meso</i> position (<b>3c</b>,<b>d</b>) show a blue shift of 50 nm in comparison to 8-chloro BODIPY (<b>1</b>). The DFT calculations reveal strong donor–acceptor interactions. The nature of the heteroatom does not affect the HOMO but perturbs the LUMO. The single-crystal X-ray structures of <b>2a</b>,<b>b</b> and <b>3c</b>,<b>d</b> show interesting supramolecular interactions. The crystal structure of <b>2a</b> shows two molecules in an asymmetric unit arranged into a complex 3D structural motif, <b>2b</b> contains a staircase-shaped arrangement of tetramers to form a 2D structural sheet, <b>3c</b> forms a sheet in a zigzag manner, and <b>3d</b> forms a sheet which contains alternating bands of ferrocenyl and BODIPY units