Tetrakispyrazolylethene: Protonation-Induced Emission.

Tetrakispyrazolylethene () was synthesized from pyrazole and hexachloroethane through a one-step substitution reaction. The increase of emission was detected both in solid and aqueous THF solution, compared with that in anhydrous THF. While the former originates from the crystal packing, the latter is attributed to the protonation-induced emission, independent of aggregation, based on the optical measurement under varying concentrations and particle-size distribution analysis.

Hexakispyrazolylethane: New Strategy for Stabilization of Hexaarylethane.

Hexakis(4-trimethylsilylpyrazol-1-yl)ethane was synthesized by the oxidative dimerization of tris(4-trimethylsilylpyrazol-1-yl)methane. Single-crystal X-ray structural analysis of hexakis(4-trimethylsilylpyrazol-1-yl)ethane showed that the ethane C-C bond (1.623(4) Å) is shorter than that in hexaphenylethane (1.

Synthesis of Triptycenemonohydroquinonedibenzoquinone by Comproportionation.

Triptycenetribenzoquinone (BQ), where the three benzene rings of triptycene are replaced by 1,4-benzoquinone (BQ) rings, is known to be reduced to triptycenetrihydroquinone (HQ). In contrast, a molecule where both BQ and HQ moieties coexist in a triptycene framework has never been reported. In this study, triptycenemonohydroquinonedibenzoquinone ((HQ)(BQ)) in which one HQ unit and two BQ units coexist was generated by comproportionation between (BQ) and (HQ) and isolated by recrystallization.