Tiara[5]arenes: Synthesis, Solid‐State Conformational Studies, Host–Guest Properties, and Application as Nonporous Adaptive Crystals

Abstract

Tiara[5]arenes (T[5]s), a new class of five‐fold symmetric oligophenolic macrocycles that are not accessible from the addition of formaldehyde to phenol, were synthesized for the first time. These pillar[5]arene‐derived structures display both unique conformational freedom, differing from that of pillararenes, with a rich blend of solid‐state conformations and excellent host–guest interactions in solution. Finally we show how this novel macrocyclic scaffold can be functionalized in a variety of ways and used as functional crystalline materials to distinguish uniquely between benzene and cyclohexane.

per-Alkoxy-pillar[5]arenes as Electron Donors: Electrochemical Properties of Dimethoxy-Pillar[5]arene and Its Corresponding Rotaxane

“…The scope of pillararenes as hosts can be expanded by substituting the rim alkoxy positions with a desired group; either by cocyclisation of a functionalised monomeric subunit with 1,4-dimethoxybenzene [21,22]; by dealkylation and further reaction of the already formed macrocycle [23][24][25]; or by preorienting the cyclisation reaction with a 2,5-substituted benzyl alcohol [26,27], the latter affording ''rim-differentiated" pillararenes where each rim is pre-functionalised with a desired group. The chemistry of these fascinating molecules has recently been extended to a new family of tiara [5]arenes that exhibit more conformational flexibility [28].…”

Adsorptive Separation of Benzene, Cyclohexene, and Cyclohexane by Amorphous Nonporous Amide Naphthotube Solids

“…[7] Macrocyclic hosts have the advantage to distinguish molecules with minor structural differences, and have been explored in separation applications. [8][9][10] Earlier this year, Sues [9] and Huangs groups [10] independently achieved the [*] H. Yao [+] School of Chemistry and Chemical Engineering Harbin Institute of Technology No.92 Xidazhi Street, Harbin 150001 (China) separation of C 6 H 6 from C 6 H 12 with the nonporous adaptive crystals (NACs) [11] of tiara [5]arene and hybrid[3]arene, respectively. However, to the best of our knowledge, the separation of the ternary mixture of C 6 H 6 , C 6 H 10 , and C 6 H 12 has not been achieved with the method of adsorptive separation.…”

“…This is much faster than most NACs which usually require several hours or a day to reach saturation. [8][9][10] The activated solid of 1 a only adsorbs C 6 H 6 . In contrast, C 6 H 6 , C 6 H 10 , and C 6 H 12 can all be adsorbed by the activated solid of 1 b.…”

Structural Diversification of Pillar[n]arene Macrocycles

“…In the first highlighted article, Sue et al. reported the synthesis of tiara[5]arenes (T[5]s) in which every benzene ring only bears one alkoxy substituent . These structures cannot be prepared by direct condensation of mono‐alkoxybenzenes as this will lead to the formation of branched or even cross‐linked structures.…”