ABSTRACT
Graphene continues to draw immense interest because of its unusual electronic and spin properties resulting from a simple structure composed of a single layer of carbon atoms arranged in a two-dimensional honeycomb pattern. Producing a band gap is probably one of the most important challenges that must be addressed before graphene can ultimately enable practical applications ranging from digital electronics to infrared nanophotonics. Chemical modification of graphene by covalently functionalizing its surface potentially allows a wider flexibility in engineering electronic structure, in particular the local density of states of the carbon atoms bound to the modifier that can result in the opening of the band gap. The graphene–metal interaction in haptic functionalization has direct consequences on the electronic properties of graphene. Metallocenes and metal-bis-arene compounds are known to be good electronic donors and graphene shows the strongest interaction with electron donor and acceptor molecules via molecular charge transfer.
