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. Two cis‐connected cyclic tetraphenylethylenes, [2]c‐CTPE and [3]c‐CTPE, were synthesized by platinum‐mediated cyclization. The strain energy of [2]c‐CTPE is up to 86.28 kJ ⋅ mol−1. [2]c‐CTPE and [3]c‐CTPE demonstrates typical Aggregation‐Induced Emission (AIE) characteristics. Moreover, both [2]c‐CTPE and [3]c‐CTPE display mechanofluorochromic properties.