Nanochannel Array within a Multilayered Network of a Planarized Dehydro[24]annulene

Abstract

Dehydro[24]annulene 1c adopts an unusual planarized conformation in the crystal. A multilayered stack of hydrogen-bonded grids delineates tightly packed nanotubular channels. The related macrocycles 1a and 1b, on the other hand, have the expected puckered conformations in the crystal.

Conjugated Macrocycles: Concepts and Applications

“…[152] Rubin and coworkers synthesized the tetra(hydroxymethyl) derivative of dehydro [24]annulene which formed tightly packed nanotubular channels in the solid state. [153] Hçger and co-workers reported the synthesis and STM images of shape-persistent oligo(phenylene-ethynylene-butadiynylene)s and triphenylene-butadiynylene macrocycles. [154] The STM images showed the formation of empty helical nanochannels, tubelike superstructures, and related nanoscale patterns.…”

Konjugierte Makrocyclen: Konzepte und Anwendungen

“…[152] Rubin und Mitarbeiter synthetisierten Tetra(hydroxymethyl)-Derivate des Dehydro [24]annulens, die dicht gepackte Nanorçhrenkanäle im Kristall bilden. [153] Hçger und Mitarbeiter berichteten über die Synthese und STM-Studien formstabiler Oligo(phenylenethinylenbutadiinylenen) und Triphenylenbutadiinylen-Makrocyclen. [154] Die STM-Bilder ließen die Bildung leerer helicaler Nanokanäle, rçhrenfçrmiger Überstrukturen und ähnlicher nanoskaliger Muster erkennen.…”

An Investigation into the Stephens–Castro Synthesis of Dehydrotriaryl[12]annulenes: Factors Influencing the Cyclotrimerization

“…This situation would normally be expected to be repulsive and counterproductive to columnar stacking. Although the stacking of dehydrobenzo[ n ]annulenes and related macrocycles into tubular columnar arrays has been reported, they comprise entirely hydrocarbon structures with no potentially repulsive intermolecular effects . In 4 however, the overlying pyridine rings are slipped and offset with respect to each other such that only edge‐to‐edge π–π contacts exist between the inner edge C1 and C5 and outer edge C3 and N1 atoms of each ring.…”

“…Although the stacking of dehydrobenzo[n]annulenes and related macrocycles into tubular columnar arrays has been reported, they comprise entirely hydrocarbon structures with no potentially repulsive intermolecular effects. [85] In 4 however, the overlying pyridine rings are slipped and offset with respect to each other such that only edge-to-edge π-π contacts exist between the inner edge C1 and C5 and outer edge C3 and N1 atoms of each ring. This gives an infinite stepped ladder arrangement of interpyridine π-π interactions, with C1-C3 and C5-N1 distances of 3.525 and 3.529 Å respectively, [86] that mitigates any repulsive dipole alignments that would arise if the center of the pyridine rings were more closely aligned.…”