Figure 10: Strategy to make large graphene quantum dots soluble. (a) Attaching 1,3,5-trialkyl phenyl moieties (marked black) covalently to the edge of graphene (blue) to shield the graphenes from one another in three dimensions. Hydrogen atoms are marked white. (b) Molecular structure of graphene quantum dot 1, containing a graphene moiety with 168 conjugated carbon atoms. The graphene moiety is marked blue and the three solubilizing groups black. (c) A theoretically energy-minimized configuration of 1 in vacuum, showing the three-dimensional enclosure of the graphene core by the alkyl chains (black) [159].