Karl Franzens University Graz
Graz University of Technology
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Karl Franzens University Graz | Graz University of Technology | |
Aspects of molecular chirality at surfaces Crystallization of organic compounds is one of the most important means in chemical and pharmaceutical industry to obtain products. However, not much is understood about important phenomena like polymorphism and optical resolution, i.e., separation of chiral compounds into their left- and right-handed forms. A promising approach is to study these two-dimensional (2D) crystallization phenomena on well-defined substrates with scanning tunneling microscopy (STM) and other surface sensitive techniques. Understanding selfassembly phenomena of organic molecules at metal surfaces is also important for new materials systems for photovoltaic and organic electronics. We investigate symmetry mismatch effects in crystallization, by 2D tiling with fivefoldsymmetric corannulene derivatives, so-called buckybowls. STM reveals interesting strategies to achieve close-packing where the symmetry actually does not allow perfect tiling. The interplay of handedness in chiral monolayers shows new cooperative effects like amplification of enantiomorphism or suppression of long-range order by chiral impurities. |