English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

A three-dimensional π-conjugated polyradicaloid molecular cage  c   -Ph14 , consisting of three Chichibabin's hydrocarbon motifs connected by two benzene-1,3,5-triyl bridgeheads, was synthesized. Compared with its linear model compound  l   -Ph4 , the prism-like  c   -Ph14 has a more rigid structure, which shows significant impact on the molecular dynamics, stability, and electronic properties. A higher rotation energy barrier for the quinoidal biphenyl units was determined in  c   -Ph14 (15.64 kcal/mol) than that of  l   -Ph4 (11.40 kcal/mol) according to variable-temperature NMR measurements, leading to improved stability, a smaller diradical character, and an increased singlet-triplet energy gap. The pressure-dependent Raman spectroscopic studies on the rigid cage  c   -Ph14 revealed a quinoidal-to-aromatic transformation along the biphenyl bridges. In addition, the ellipsoidal cavity in the cage allowed selective encapsulation of fullerene C 70 over C 60 , with an associate constant of about 1.43 × 10 4 M -1 . Moreover,  c   -Ph14 and  l   -Ph4 exhibited similar redox behavior and their cationic species (  c   -Ph14   6+  and  l   -Ph4   2+  ) were obtained by chemical oxidation, and the structures were identified by X-ray crystallographic analysis. The biphenyl unit showed a twisted conformation in  l   -Ph4   2+  and remained coplanarity in  c   -Ph14   6+  . Notably, molecules of  c   -Ph14   6+  form a one-dimensional columnar structure via close π-π stacking between the bridgeheads.

A Chichibabin’s Hydrocarbon-Based Molecular Cage: The Impact of Structural Rigidity on Dynamics, Stability, and Electronic Properties