Self‐Assembly of Aminocyclopropenium Salts: En Route to Deltic Ionic Liquid Crystals

Abstract

Aminocyclopropenium ions have raised much attention as organocatalysts and redox active polymers. However, the self‐assembly of amphiphilic aminocyclopropenium ions remains challenging. The first deltic ionic liquid crystals based on aminocyclopropenium ions have been developed. Differential scanning calorimetry, polarizing optical microscopy and X‐ray diffraction provided insight into the unique self‐assembly and nanosegregation of these liquid crystals. While the combination of small headgroups with linear p‐alkoxyphenyl units led to bilayer‐type smectic mesophases, wedge‐shaped units resulted in columnar mesophases. Upon increasing the size and polyphilicity of the aminocyclopropenium headgroup, a lamellar phase was formed.

Dual stimuli-responsive porous ionic liquids with reversible phase transition behavior based on ionic liquid crystals for CO2 and C2H4 adsorption

“…1c). 22 Besides, the typical columnar liquid crystal textures of [C 4 ImC 3 N 111 ][NTf 2 ] 2 were obtained (Fig. 1f–i).…”

Unusual Alternating Crystallization-Induced Emission Enhancement Behavior in Nonconjugated ω-Phenylalkyl Tropylium Salts

“…The even-numbered linker analogues ( 1 - 0 , 1-II , and 1-IV ) are novel clusteroluminogens with CIEE phenomenon, while the odd-numbered linker compounds ( 1-I and 1-III ) are novel room-temperature ionic liquids. To the best of our knowledge, 1-I and 1-III marked the first examples of the nonbenzenoid aromatic tropylium ion in ionic liquids, despite the relevant cyclopropenium ionic liquids having been known for years. , …”

Current Topics in Ionic Liquid Crystals

“…Recently, Laschat and co‐workers described deltic ILCs, where either linear 4‐alkoxyphenyl or wedge‐shaped 4‐[(3,4,5‐trialkoxybenzoyl)oxy]phenyl moieties carried trisaminocyclo‐propenium units as „extended guanidinium“ cationic head group (Figure 13). [125,126] Depending on the relative volume requirements of head group and core unit SmA or Col r /Col h phases were formed in the former and latter case respectively.…”

“…The values of 5(C 12 ) , and 5(C 14 ) were taken from ref [127] . The Figure was taken and adapted from ref [125] . This is an open access article distributed under the terms of the Creative Commons CC BY license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.…”