Attaching hexylbenzene and poly(9,9-dihexylfluorene) to brominated graphenevia Suzuki coupling reaction

Halogenated organic compounds can represent a useful class of intermediates as they could act as precursors to a number of organometallic species and suitable substrates for metal-catalyzed cross coupling reactions. Here we present an interesting means of functionalizing graphene substrates based on a Suzuki coupling reaction. Firstly, brominated chemically converted graphene sheets were obtained by treating the graphene with ultrasonic assisted bromination. Next, the brominated graphene were modified via the formation of C–C bond between the brominated graphene and the employed aryl boronic. 4-Hexylphenyl boronic acid and 7-bromo-9,9-dihexyl-fluorene-2-ylboronic acids were chosen to show the utility of this reaction scheme in functionalizing graphene. The solubility and optical properties of the grafted material was improved dramatically by the modification. This will open a new interesting filed for the exploitation and application of graphene based materials.