Direct visualization of enantiospecific substitution of chiral guest molecules into heterochiral molecular assemblies at surfaces

Site-specific chiral recognition in a two-dimensional heterochiral structure leading to highly enantiospecific substitution by a chiral guest was observed by scanning tunneling microscopy (STM). Thus, in the case of succinic acid (SU) on Cu(110), which forms two chiral motifs denoted D- and L-SU, (R,R)-tartaric acid ((R,R)-TA = R) only substitutes L sites (see picture; in the STM image R appears as "slots" aligned -20° to the [001] direction). (Figure Presented).