Orthogonal Action of Noncovalent Interactions for Photoresponsive Chiral Columnar Assemblies

Abstract

Gut gestapelt: Helicale columnare Architekturen entstehen in einer hierarchischen Selbstorganisation unter Beteiligung von H‐Brücken, π‐π‐ und Ion‐Dipol‐Wechselwirkungen (siehe Bild). Die strategische Kombination dieser supramolekularen Wechselwirkungen in mesomorphen Systemen liefert Materialien, bei denen photoinduzierte Chiralität und der Einbau von Ionen genutzt werden können, um multifunktionelle Flüssigkristalle zu entwerfen.

Chirality Transfer and Modulation in LB Films Derived From the Diacetylene/Melamine Hydrogen‐Bonded Complex

“…The signal for NH b of the central melamine unit also shifted downfield in the resulting complex. This 1 H‐NMR result was in accordance with that of the earlier work . When the PCDA/T complex solution was subjected to UV‐Vis absorption characterization, the absorption band for melamine unit (at 280 nm) was found to be obviously redshifted relative to the corresponding band in pure T solution (at 260 nm, as shown in Fig.…”

“…Using a combination of complementary hydrogen bonding to melamine derivatives and π–π stacking interactions, Versa's group has formed a remarkable self‐organizing ability of the propeller‐like hydrogen‐bonded complexes. This ability was ascribed to the synergistic action of the π–π stacking tendency of the melamine‐derived core and the strong lateral interactions between V‐shaped azobenzene molecules . However, the relationship between the helical packing of the aromatic cores and the peripheral flexible chains are still not fully understood.…”

Inspecting the Electronic Architecture and Semiconducting Properties of a Rosette‐Like Supramolecular Columnar Liquid Crystal

“…In addition to the diffuse halo at 4.5 Å, which is characteristic of the liquid‐crystal state, a sharp and intense reflection at 3.5 Å indicates long‐range intracolumnar order. These lattice parameters are sufficiently high to support the formation of a rosette‐like structure as a stacking unit and a calculated density value ρ =0.88 g cm −3 is obtained …”

“…In this respect, we decided to exploit a combined columnar/supramolecular strategy, by exploring, from experimental and theoretical points of view, a unique structure consisting of a rosette with six‐fold symmetry formed by H‐bonding of six melamines and six carboxylic acids. This rosette structure, which has melamine–melamine and melamine–acid H‐bonds, was reported to form highly organized columnar mesophases . However, the achievement of this type of hierarchical organization with semiconducting units to enforce a novel organization with a high degree of order and 1D nanosegregation that would permit the appropriate electronic distribution for charge transport has not been approached before.…”

“…H‐bonding interactions between M and acid TPC 10 were analyzed by 1 H NMR spectroscopy. The signals of the N‐H protons of M in CD 2 Cl 2 solution, which overlapped between 4.60 and 4.90 ppm, were shifted to lower fields in the spectrum of the mixture of M with TPC 10 in a 1:1 ratio . FTIR studies allowed H‐bonding interactions to be observed in the bulk.…”