Synthesis and Electronic Properties of Arene-Fused o-Carborane

A transition-metal-free, base-mediated intramolecular C-arylation of o -carborane provides facile access to arene - fused o -carboranes. The new naphthyl-fused o -carborane 2, as a fluoranthene analogue, was obtained with the reaction of 1-(8-Br-1-naphthyl)- o -carborane under basic conditions. This method is also applicable to the synthesis of biaryl-fused o -carboranes. The corresponding arene-fused nido -carborane was further obtained after deboronation with n Bu 4 NF. The fluorescence quantum efficiency of 5 has shown significant improvement compared to fluoranthene (Φ PL: 0.79 vs 0.2). In addition, the aromaticity of the o -carborane-annulated ring systems in these new compounds was studied and found to be enhanced compared to the corresponding rings of fluoranthene.