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.

Capture of Sulfur Mustard by Pillar[5]arene: From Host-Guest Complexation to Efficient Adsorption Using Nonporous Adaptive Crystals

“…This novel class of materials was termed as nonporous adaptive crystals (NACs) ( Jie et al., 2018a , 2018b ). Very recently, NACs of other macrocycles such as biphen[ n ]arene ( Wang et al., 2019 ), hybrid[3]arene ( Zhou et al., 2020 ), leaning towerarene ( Wu et al., 2020 ), geminiarene ( Wu and Yang, 2019 ), and tiararenes ( Yang et al., 2020 ) have also been reported, showing interesting adsorption and separation properties. Notice that, in our vapor adsorption tests, SM simulants were utilized because no effective protection was available during the experiments for testing the real SM.…”

Harnessing Shape Complementarity for Upgraded Cyclohexane Purification through Adaptive Bottlenecked Pores in an Imidazole‐Containing MOF

“…In terms of the general problem concerning the trade-off between uptake and selectivity in various separations, [29] MAF-stu-13 outperforms all others featuring a high liquid separation selectivity of 412 along with high Bz uptake (Figure 4 f). In particular, the ultrahigh product purity (99.4 %) strengthens its advantage in practical application; other candidate materials include: hybrid [3]arene (97.5 %), [19] T[5]-(OMe) 5 (92.3 %), [18] [Li 2 Zn 2 (NO 2 -bdc) 3 (bpy)] (95 %) [16] and [Zn 4 (EGO 2 ) 2 (tdc) 2 (dabco)] (selectivity 92). [14] In conclusion, this work presents a solution to breaking the bottleneck (i.e.…”

Harnessing Shape Complementarity for Upgraded Cyclohexane Purification through Adaptive Bottlenecked Pores in an Imidazole‐Containing MOF

“…[44] Presumably, implementation of shape complementarity can be beneficial to gaining volumetric uptake, which is important for fixed-bed column chromatographic separation. We compared the gravimetric/volumetric uptakes of MAF-stu-13 with those of several porous [7][8][9][10][11][12][13][14][15][16] and nonporous [17][18][19][20][21] crystals (Figure 4 e; Supporting Information, Table S7). The volumetric uptake (176.5 g L À1 ) of MAF-stu-13 exceeds those of selected materials except for an adaptive pillararene host, EtP6b, (with CH uptake 263.6 g L À1 ; however, relative uptake only 55.1 %) reported recently.…”

“…[8][9][10][11][12][13][14][15][16][17][18][19][20][21] To target high-efficiency, upgraded liquid-phase purification, there must be a clear cut-off point for Bz/CH separation to ensure high selectivity; on the other hand, it should be favorable to attain high Bz uptake capacity to boost efficiency. Recently, nonporous adaptive crystals [17][18][19][20][21] were investigated for adsorptive separation of Bz and CH, reaching a product purity of 97.5 % at best for a hybrid [3]arene; [19] yet it seems difficult to balance the selectivity and efficiency for this type of materials (see below). Although the potential of porous metal-organic frameworks (MOFs) for highly selective Bz/CH adsorption, featuring different mechanisms, has been demonstrated earlier, [7][8][9][10][11][12][13][14][15][16] most works only provided single-component vapor sorption isotherms, and only a few evaluated the actual separation performances.…”