Synthesis of a Novel Chiral Squaraine Dye and Its Unique Aggregation Behavior in Solution and in Self‐Assembled Monolayers

An L-proline-derived amphiphilic squaraine dye displays unique self- assembly behavior in solution, forming new aggregates with large and symmetrical exciton splitting, while forming layered structures by an unprecedented “self-templating” effect on graphite surfaces. This unusual aggregation behavior is most likely the result of the dye's chiral molecular structure (see figure). These observations should facilitate the design of related self-assembled materials for (supra)molecular electronics.