Metalla-phenalene complexes: synthesis, structure and aromaticity

Metallaaromatics show a diversity of aromaticity. In this work, we report the synthesis and structural characterization of the first rhena-phenalene complexes. In addition to the Huckel aromaticity and sigma-aromaticity, pseudo pi anti-aromaticity is observed. DFT computations show that this anti-aromaticity (paramagnetic properties) is induced by the fused aromatic naphthyl ring.