Vernier Templating of Nanoscopic Porphyrin Rings

摘要

In nature, DNA replication constitutes a well-known template-assisted process, in which each individual strand of the original DNA serves as a template for production of the complementary strand. Templation is now widely recognized as a means to selectively connect different components with each other, thereby increasing molecular complexity and function. However, upon increasing the dimensions of the synthetic target, larger and more complex template molecules are required. Such sophisticated templates are, however, not always (easily) available, and thus the selective preparation of architectures beyond the nanosize becomes incredibly challenging. An elegant solution for this problem is the use of Vernier complexes; this approach makes use of the difference in the number of binding sites in the templating agent and the molecular building blocks that are programmed to be coupled. In Vernier complexes, the number of binding sites is the lowest common multiple between the host (that needs to be coupled) and guest (template) system, and thus smaller and simpler template molecules may selectively give access to relatively large structures (Figure 1) using relative little synthetic input. Although Vernier templating has all the characteristics of a powerful tool for the creation of molecular complexity, surprisingly only a few synthetic examples have been reported to date.