Surface-confined self-assembled janus tectons: A versatile platform towards the noncovalent functionalization of graphene

A general strategy for simultaneously generating surface-based supramolecular architectures on flat sp²-hybridized carbon supports and independently exposing on demand off-plane functionality with controlled lateral order is highly desirable for the noncovalent functionalization of graphene. Here, we address this issue by providing a versatile molecular platform based on a library of new 3D Janus tectons that form surface-confined supramolecular adlayers in which it is possible to simultaneously steer the 2D self-assembly on flat C(sp²)-based substrates and tailor the external interface above the substrate by exposure to a wide variety of small terminal chemical groups and functional moieties. This approach is validated throughout by scanning tunneling microscopy (STM) at the liquid-solid interface and molecular mechanics modeling studies. The successful self-assembly on graphene, together with the possibility to transfer the graphene monolayer onto various substrates, should considerably extend the application of our functionalization strategy.