We have synthesized a series of halogen‐end‐capped oligo‐phenylene‐ethynylenes to study interactions at the solid/liquid interface and in crystal structures. Here we probe the interplay and diversity of intermolecular interactions between halide end‐groups and oligo‐phenylene‐ethynylene backbones through solution depositions (2D) and X‐ray crystal structures (3D). The STM images and crystal structures reveal a striking complementarity in each case.
In the field of material science functionalization of substrate surfaces (e.g. metal, graphite) with organic molecules is of increasing interest. Desirable targets are molecules with functional groups providing for two‐dimensional assembly and three‐dimensional crystal growth. We have synthesized a series of halogen‐end‐capped oligo‐phenylene‐ethynylenes (OPEs) to study the interactions at the solid/liquid interface and in crystal structures. Organohalides can be involved in a wide variety of intermolecular interactions such as C–X···H, C–X···X–C and C–X···π‐orbitals. The range of halogen‐based interactions and the diversity of intermolecular forces along different crystal axes makes the investigation of such structures particular interesting and challenging. Here we probe the interplay of halide end‐groups and the backbone of an OPE to investigate the intermolecular interactions in both solution depositions (2D) and X‐ray crystal structures (3D). The STM images and the crystal structures of each OPE reveal striking packing similarities. For each molecule, a plane in the crystal structure with an arrangement of molecules resembling its two‐dimensional packing on a flat surface was found. These results support the hypothesis of sheet‐by‐sheet crystal growth and suggest that flat surfaces would be ideal interfaces to promote crystal growth for halide‐end‐capped OPEs.
Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer‐reviewed, but not copy‐edited or typeset. They are made available as submitted by the authors.
Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.