Synthesis and Properties of [3]Rotaxanes with Two Oligo(para-phenylene) Axles.

Oligo(para-phenylene) (PPn) is a π-conjugated compound where phenylene units are directly connected at the 1,4-positions. Utilizing the catalytic activity of the macrocyclic dihydrodibenzophenanthroline-Ni complex, we succeeded in the synthesis of [3]- and [2]rotaxanes with PPn axles by biaryl coupling. The size of the macrocycle was critical to synthesize [3]rotaxanes, which consist of two oligo(para-phenylene) axles, in good yields.

Synthesis of Interlocked and Non-Interlocked Deca(para-phenylene) Derivatives by Ni-mediated Biaryl Coupling.

Oligo(para-phenylene) (PPn) is a compound composed of directly connected 1,4-phenylene moieties. The synthesis of PPn composed of six or more phenylene moieties with no substituent at the internal phenylene moiety has been challenging because of its low solubility. Herein we synthesized oligo(para-phenylene)[2]rotaxanes, including a deca(para-phenylene)[2]rotaxane, with a defined number of phenylene moieties.