A Highly Strained All‐Phenylene Conjoined Bismacrocycle

Herein, we report the precise synthesis of a 3D highly strained all‐phenylene bismacrocycle, termed conjoined (1,4)[10]cycloparaphenylenophane ( SCPP[10] ). This structure consists of a twisted benzene ring which is bridged twice by phenylene units anchored in two para‐positions. The conjoined structure of SCPP[10] was confirmed in real space at the atomic scale by scanning tunneling microscopy. Theoretical calculations indicate that this bismacrocycle has a very high strain energy of 110.59 kcal mol −1 and the largest interphenylene torsion angle of 46.07° caused by multiple repulsive interactions. Furthermore, a 1:2 host–guest complex of SCPP[10] and [6,6]‐phenyl‐C 61 ‐butyric acid methyl ester was investigated, which represents the first peanut‐shaped 1:2 host–guest complex based on bismacrocycles.