Theoretically Predicted New Multicyclic Compound by Stilbene Dimer.

Host molecules with a cavity or scaffold with a limited space have been utilized for photodimerization of trans‐stilbene dimer with [2 + 2] cycloaddition. The degrees of freedom of the molecules inside the cavity are generally constrained. The cycloaddition reaction of trans‐stilbene dimer was investigated for variously constrained with inter‐stilbene distances and torsional angles by ab‐initio calculations at MP2/6‐31G* level of theory. In a very short inter‐stilbene distance, a new multicyclic compound (P1) was obtained, while [2 + 2] cycloaddition product (P2) was obtained from a wide range of geometries. Both inter‐stilbene distance and torsional angle play a pivotal role in determining which product (P1 or P2) could be obtained from the cycloaddition reaction of trans‐stilbene dimer. [ABSTRACT FROM AUTHOR]