The present interest in graphene, a naturally occurring two-dimensional polymer 1 (2DP), makes clear that there is a lack of synthetic methods that would allow accessing covalently bonded monolayer sheets with internal periodicity under conditions mild enough to allow for the organic chemistry repertoire to be applied. The presentation will start with a brief overview of the many approaches performed so far towards this goal. They led to invaluable insights and paved the way for the first feasible solutions reported in 2012 by the author's laboratory. The concept rests upon three steps: (a) careful monomer design, (b) interfacial 2,4,6 and single crystalline pre-ordering 3,5 of the monomers and (c) fixation of the ordered state preferably by light-induced polymerizations. The lecture will discuss the developments which took place since this first unequivocal case of a 2DP with an all carbon structure to the present point where we got closer to a technological exploitation with a remarkably simple system. 5

Vapor-phase post-synthetic modification (VP-PSM) is herein described. VP-PSM is a tool that overcomes limitations of standard PSM methods by giving a higher yield in short reaction times and will give more flexibility in designing metal-organic frameworks with functionalization for chemical and physical applications.

Synthetic covalent monolayer sheets and their subclass, two-dimensional polymers are of particular interest in materials science because of their special dimensionality which renders them very different from any bulk matter. However, structural analysis of such entities is rather challenging, and there is a clear need for additional analytical methods. The present study shows how tip-enhanced Raman spectroscopy (TERS) can be performed on monomer monolayers and the covalent sheets prepared from them by [4 + 4]-cycloaddition to explore rather complex structural and mechanistic issues. TERS is a surface analytical method that combines the high lateral resolution of scanning probe microscopy (SPM) with a greatly enhanced Raman scattering intensity. The high spatial resolution (<60 nm) and the significantly improved sensitivity (contrast factor of >4000) compared to confocal Raman microscopy provides new insights into the formation of this new and exciting material, namely significant consumption of the reactive units (anthracenes) and exclusion of the alternative [4 + 2]-cycloaddition. Moreover, due to the high lateral resolution, it was possible to find a first spectroscopic hint for step growth as the dominant mechanism in the formation of these novel monolayer sheets. In addition, TERS was used to get first insights into the phase behavior of a comonomer mixture.

The novel hydrocarbon propeller-shaped D3h-symmetric cyclophane (3), "anthraphane", was prepared through a revisited and optimized gram-scale synthesis of the key building block anthracene-1,8-ditriflate 7. Anthraphane has a high tendency to crystallize and single crystals in size ranges of 100-200 μm are easily obtained from different solvents. The crystallization behavior of 3 was extensively studied to unravel packing motifs and determine whether the packing can be steered into a desired direction, so to allow topochemical photopolymerization. SC-XRD shows that anthraphane packs in layers irrespective of the solvent used for crystallization. However, within the layers, intermolecular arrangements and π-π interactions of the anthracene units vary strongly. Four interaction motifs for the anthracene moieties are observed and discussed in detail: two types of exclusively edge-to-face (etf), a mixture of edge-to-face and face-to-face (ftf), and no anthracene-anthracene interaction at all. To elucidate why an exclusive ftf stacking was not observed, electrostatic potential surface (EPS) calculations with the semiempirical PM3 method were performed. They show qualitatively that the anthracene faces bear a strong negative surface potential, which may be the cause for this cyclophane to avoid ftf interactions. This combined crystallographic and computational study provides valuable insights on how to create all-ftf packings.