cis‐Linked Cyclotetraphenylenes: Synthesis, Structures and Fluorescence Properties

cis-Linked cyclotetraphenylene dimer [2]c-CTPE and trimer [3]c-CTPE were synthesized via Pt-mediated cyclization of cis-diboronated tetraphenylethene. The structure of [2]c-CTPE has been confirmed by single crystal X-ray diffraction. The strain energy of [2]c-CTPE and [3]c-CTPE was calculated to be 86.28·kJ mol-1 and 9.23 kJ·mol-1, respectively. [2]c-CTPE and [3]c-CTPE are typical AIEgens and show mechanofluorochromic properties. The comparisons of cis-linked cyclotetraphenylenes with gem-linked cyclotetraphenylenes were also discussed.