The field of macrocyclic host–guest chemistry was born with the discovery of crown ethers (CEs) by Pederson and has been the catalyst that led to the field of supramolecular chemistry more generally (Pedersen, 1967). Apart from CEs, the diversity of macrocyclic hosts with different shapes and cavities is staggering and many other examples such as cyclodextrins (CDs), (Szejtli, 1998; Harada, 2001; Davis and Brewster, 2004; Antoniuk and Amiel, 2016) cucurbit[n]urils (CB[n]s), (Lagona et al., 2005; Masson et al., 2012; Ni et al., 2014; Murray et al., 2017; Palma et al., 2017; Chen et al., 2022a) calix[n]arenes (CA[n]s), (Diamond and McKervey, 1996; Baldini et al., 2007; Kim and Quang, 2007; Guo and Liu, 2014) pillar[n]arenes (PA[n]s) (Ogoshi et al., 2008; Xue et al., 2012; Kakuta et al., 2018; Ogoshi et al., 2018; Xiao et al., 2018; Xiao et al., 2019a; Xiao et al., 2019b; Xiao et al., 2019c; Ma et al., 2022; Wang et al., 2022) and other macrocyclic molecules have been reported (Chen and Han, 2018; Wang et al., 2020a; Peng et al., 2020; Wu et al., 2022; Zhang and Li, 2022). The dynamic binding behaviour of many different hosts and guests endows these materials with useful properties including stimuli-responsiveness, self-healing, degradability and recyclability. As a result, host–guest chemistry plays an important role in many research areas, such as supramolecular polymers, (Harada et al., 2009; Xiao et al., 2020a; Wu and Xiao, 2020; Hua et al., 2022) supramolecular networks/frameworks, (Wang et al., 2018; Wang et al., 2020b; Huang et al., 2020; Li et al., 2021) drug delivery, (Duan et al., 2013; Braegelman and Webber, 2019) artificial light-harvesting systems, (Xiao et al., 2019d; Xiao et al., 2022; Xiao et al., 2023) and dynamic hydrogels (Xiao et al., 2019e; Chen et al., 2022b) etc. In this context, we organized the Research Topic “host–guest chemistry of macrocycles” in 2020 which led to the publication of 15 important articles demonstrating the latest research in this area (Xiao et al., 2020b). Because of the importance and popularity of this Research Topic, we have now organised a second volume on this topic. Herein, we briefly introduce the works in this new Research Topic.
The structure of molecules in the solution is determined by the intrinsic properties of the molecules and their interaction with the surrounding solvent. Therefore, the protonation site of a molecule depends on both their intrinsic strengths and different stabilizations by the solvent. The complexation of a guest molecule with multiple basic sites and a macrocyclic host could stabilize, probe, or facilitate the formation of a specific protomer. To verify this, Alcázar et al. investigated the impact of CB[7] on the synthetic dyes 7-(dialkylamino)-aza-coumarin derivatives (SACs), which bear two basic sites in their structure (Alcázar et al., 2022). They first synthesized three styryl-derived SACs, namely SAC1, SAC2, and SAC3, which were fully characterized by HR ESI-MS, IR, and NMR. The spectral behavior of the SACs in the absence and presence of CB7 was studied. In contrast to the heterocyclic nitrogen, the dialkylamino nitrogen in SAC1 (pKa = 1.30) and SAC2 (pKa = 2.35) are more likely to be protonated. However, the protonation of SAC3 could take place both in the heterocyclic nitrogen (pKa = 1.67) and dialkylamino nitrogen (pKa = 1.75) independently. These protomers of the SACs were confirmed by UV-vis absorbance experiments and DFT calculations. Intriguingly, in the presence of CB[7], the heterocyclic nitrogen was favored to be protonated over the dialkylamino nitrogen, which may be due to a change in the protonation preference of SACs induced by CB[7] upon host–guest interaction. Notably, a bathochromic shift of ≈4500 cm−1 (SAC1-3) was observed in the presence of CB[7].
Fluorescent indicator displacement (FID) assays are an excellent method to probe analytes via the conversion of receptors into optical sensors that can sense binding of different guests. Given the rapid development of supramolecular host–guest chemistry, macrocycle-based FID assays have received considerable attention due to their potential in the area of chemical sensing. Food additives based on phenolic compound play a key role in the food industry on account of their remarkable antibacterial and antioxidant properties. However, the excessive use and accumulation of food additives in the environment is gradually increasing and is responsible for significant environmental concern. In this context, Duan et al. prepared a novel FID assay based on a cationic PA[6] (CP6) for the detection of some vital phenolic food additives, such as p-gallic acid (GA), trans-ferulic acid (FA) and coumaric acid (CA) (Duan et al., 2022a). The 6-p-toluidinylnaphthalene-2-sulfonate (TNS) was used as the fluorescent indicator in this FID system due to its enhanced emission in non-polar environments. Upon the host-guest complexation of CP6 and TNS, the fluorescence of TNS was switched on. However, in the presence of GA, FA and CA, the fluorescence was turned off due to the guest’s displacement from the cavity of CP6. As a result, the host–guest chemistry-based FID system can be used as a sensor towards these phenolic food additives.
In a minireview paper, Duan et al. further summarized recent progresses on FID assays based on macrocyclic arenes (Duan et al., 2022b). The authors mainly divided the content to two parts: CA[n]-based FID assays and PA[n]-based FID assays. Due to their unique macrocyclic structure and versatile host–guest binding behaviors, the combination of CA[n]s or PA[n]s with various fluorophores is broadly used in FID assays for the specific and selective sensing of analytes. There is a larger diversity of reported analytes including neutral molecules, anions, cations, and biomolecules. Finally, the authors discussed the prospect and remaining challenges in this research area.
Hydrophobic interactions are another important non-covalent force in supramolecular chemistry. Nanoparticles (NPs) formed by surfactants in water are usually driven by hydrophobic interactions. In this Research Topic, Zhu et al. reported that multiple W/O/W (W: water, O: oil) emulsions can be obtained by using CaCO3 NPs and a surfactant (SDS) of different concentrations (Zhu et al., 2022). Once the low surface-activity CaCO3 NPs are treated, they become surface-active in situ with the addition of SDS. These emulsions possess very high stability, which can stand for at least 1 month without coalescence. The strategy provided in this work not only promotes stabilization of multiple emulsions but also avoids the tedious synthesis often associated with colloidal NPs.
In conclusion, this Research Topic collects some new advances in macrocycle-based host–guest chemistry covering a broad range of supramolecular chemistry research. As the field further develops, we believe host–guest chemistry will continue to be a source of intrigue for basic science and gradually, with investment and critical thinking provide real-world applications across health, environmental and materials science.
Statements
Author contributions
All authors listed have made a substantial, direct, and intellectual contribution to the work and approved it for publication.
Funding
We acknowledge financial support by the National Natural Science Foundation of China (21702020, 21801139) and Science Foundation Ireland (SFI) co-funded under the European Regional Development Fund under Grant number 12/RC/2275_P2.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Publisher’s note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.
References
1
Alcázar J. J. Márquez E. García-Río L. Robles-Muñoz A. Fierro A. Santos J. G. et al (2022). Changes in protonation sites of 3-styryl derivatives of 7-(dialkylamino)-aza-coumarin dyes induced by cucurbit[7]uril. Front. Chem.10, 870137. 10.3389/fchem.2022.870137
2
Antoniuk I. Amiel C. (2016). Cyclodextrin-Mediated Hierarchical self- assembly and its potential in drug delivery applications. J. Pharm. Sci.105, 2570–2588. 10.1016/j.xphs.2016.05.010
3
Baldini L. Casnati A. Sansone F. Ungaro R. (2007). Calixarene-based multivalent ligands. Chem. Soc. Rev.36, 254–266. 10.1039/B603082N
4
Braegelman A. S. Webber M. J. (2019). Integrating stimuli-responsive properties in host-guest supramolecular drug delivery systems. Theranostics9, 3017–3040. 10.7150/thno.31913
5
Chen C. F. Han Y. (2018). Triptycene-derived macrocyclic arenes: From Calixarenes to Helicarenes. Acc. Chem. Res.51, 2093–2106. 10.1021/acs.accounts.8b00268
6
Chen F. Huang Z. Li T. Xiao T. Wang S. Bai G. et al (2022). Highly Deformable and Durable hydrogels through Synergy of covalent Crosslinks and Nanosheet‐Reinforced dynamic interactions toward Flexible sensor. Adv. Mater. Technol.8, 2200745. 10.1002/admt.202200745
7
Chen X. Huang Z. Sala R. L. McLean A. M. Wu G. Sokolowski K. et al (2022). On-resin Recognition of aromatic Oligopeptides and Proteins through host-enhanced Heterodimerization. J. Am. Chem. Soc.144, 8474–8479. 10.1021/jacs.2c02287
8
Davis M. E. Brewster M. E. (2004). Cyclodextrin-based pharmaceutics: Past, present and future. Nat. Rev. Drug Discov.3, 1023–1035. 10.1038/nrd1576
9
Diamond D. McKervey M. A. (1996). Calixarene-based sensing agents. Chem. Soc. Rev.25, 15–24. 10.1039/CS9962500015
10
Duan Q. Wang F. Lu K. (2022). Recent advances in macrocyclic arenes-based fluorescent indicator displacement assays. Front. Chem.10, 973313. 10.3389/fchem.2022.973313
11
Duan Q. Xing Y. Guo K. (2022). The detection of food additives using a fluorescence indicator based on 6– p–Toluidinylnaphthalence-2-sulfonate and cationic pillar[6]arene. Front. Chem.10, 925881. 10.3389/fchem.2022.925881
12
Duan Q. Cao Y. Li Y. Hu X. Xiao T. Lin C. et al (2013). pH-Responsive supramolecular vesicles based on water-soluble pillar[6]arene and ferrocene derivative for drug delivery. J. Am. Chem. Soc.135, 10542–10549. 10.1021/ja405014r
13
Guo D.-S. Liu Y. (2014). Supramolecular chemistry of p-Sulfonatocalix[n]arenes and its Biological applications. Acc. Chem. Res.47, 1925–1934. 10.1021/ar500009g
14
Harada A. (2001). Cyclodextrin-based molecular Machines. Acc. Chem. Res.34, 456–464. 10.1021/ar000174l
15
Harada A. Takashima Y. Yamaguchi H. (2009). Cyclodextrin-based supramolecular polymers. Chem. Soc. Rev.38, 875–882. 10.1039/B705458K
16
Hua B. Shao L. Li M. Liang H. Huang F. (2022). Macrocycle-based Solid-State supramolecular polymers. Acc. Chem. Res.55, 1025–1034. 10.1021/acs.accounts.2c00011
17
Huang Z. Chen X. Wu G. Metrangolo P. Whitaker D. McCune J. A. et al (2020). Host-enhanced Phenyl-Perfluorophenyl Polar-π interactions. J. Am. Chem. Soc.142, 7356–7361. 10.1021/jacs.0c02275
18
Kakuta T. Yamagishi T.-a. Ogoshi T. (2018). Stimuli-Responsive supramolecular assemblies constructed from pillar[n]arenes. Acc. Chem. Res.51, 1656–1666. 10.1021/acs.accounts.8b00157
19
Kim J. S. Quang D. T. (2007). Calixarene-derived fluorescent probes. Chem. Rev.107, 3780–3799. 10.1021/cr068046j
20
Lagona J. Mukhopadhyay P. Chakrabarti S. Isaacs L. (2005). The Cucurbit[n]uril Family. Angew. Chem. Int. Ed.44, 4844–4870. 10.1002/anie.200460675
21
Li Y. Li Q. Miao X. Qin C. Chu D. Cao L. (2021). Adaptive Chirality of an Achiral cucurbit[8]uril-based supramolecular organic framework for Chirality Induction in water. Angew. Chem. Int. Ed.60, 6744–6751. 10.1002/anie.202012681
22
Ma L. Tang R. Zhou Y. Bei J. Wang Y. Chen T. et al (2022). Pillar[5]arene-based [1]rotaxanes with salicylaldimine as the stopper: Synthesis, characterization and application in the fluorescence turn-on sensing of Zn(2+) in water. Chem. Commun.58, 8978–8981. 10.1039/d2cc02893j
23
Masson E. Ling X. Joseph R. Kyeremeh-Mensah L. Lu X. (2012). Cucurbituril chemistry: A tale of supramolecular success. RSC Adv.2, 1213–1247. 10.1039/C1RA00768H
24
Murray J. Kim K. Ogoshi T. Yao W. Gibb B. C. (2017). The aqueous supramolecular chemistry of cucurbit[n]urils, pillar[n]arenes and deep-cavity cavitands. Chem. Soc. Rev.46, 2479–2496. 10.1039/c7cs00095b
25
Ni X.-L. Xiao X. Cong H. Zhu Q.-J. Xue S.-F. Tao Z. (2014). Self-Assemblies based on the “Outer-surface interactions” of cucurbit[n]urils: New Opportunities for supramolecular Architectures and materials. Acc. Chem. Res.47, 1386–1395. 10.1021/ar5000133
26
Ogoshi T. Kakuta T. Yamagishi T. A. (2018). Applications of pillar[n]arene-based supramolecular assemblies. Angew. Chem. Int. Ed.58, 2197–2206. 10.1002/anie.201805884
27
Ogoshi T. Kanai S. Fujinami S. Yamagishi T.-A. Nakamoto Y. (2008). para-Bridged Symmetrical pillar[5]arenes: Their Lewis acid Catalyzed synthesis and host–guest property. J. Am. Chem. Soc.130, 5022–5023. 10.1021/ja711260m
28
Palma A. Artelsmair M. Wu G. Lu X. Barrow S. J. Uddin N. et al (2017). Cucurbit[7]uril as a supramolecular artificial Enzyme for Diels–Alder Reactions. Angew. Chem. Int. Ed.56, 15688–15692. 10.1002/anie.201706487
29
Pedersen C. J. (1967). Cyclic polyethers and their complexes with metal salts. J. Am. Chem. Soc.89, 7017–7036. 10.1021/ja01002a035
30
Peng S. He Q. Vargas-Zúñiga G. I. Qin L. Hwang I. Kim S. K. et al (2020). Strapped calix[4]pyrroles: From syntheses to applications. Strapped calix[4]pyrroles syntheses Appl. Chem. Soc. Rev.49, 865–907. 10.1039/C9CS00528E
31
Szejtli J. (1998). Introduction and general Overview of cyclodextrin chemistry. Chem. Rev.98, 1743–1754. 10.1021/cr970022c
32
Wang J. Cen M. Wang J. Wang D. Ding Y. Zhu G. et al (2022). Water-soluble pillar[4]arene[1]quinone: Synthesis, host-guest property and application in the fluorescence turn-on sensing of ethylenediamine in aqueous solution, organic solvent and air. Chin. Chem. Lett.33, 1475–1478. 10.1016/j.cclet.2021.08.044
33
Wang L. Cheng L. Li G. Liu K. Zhang Z. Li P. et al (2020). A self-Cross-Linking supramolecular polymer network Enabled by crown-Ether-based molecular Recognition. J. Am. Chem. Soc.142, 2051–2058. 10.1021/jacs.9b12164
34
Wang S. Xu Z. Wang T. Xiao T. Hu X.-Y. Shen Y.-Z. et al (2018). Warm/cool-tone switchable thermochromic material for smart windows by orthogonally integrating properties of pillar[6]arene and ferrocene. Nat. Commun.9, 1737. 10.1038/s41467-018-03827-3
35
Wang X. Jia F. Yang L. P. Zhou H. Jiang W. (2020). Conformationally adaptive macrocycles with flipping aromatic sidewalls. Conformationally Adapt. macrocycles Flip. aromatic sidewalls. Chem. Soc. Rev.49, 4176–4188. 10.1039/d0cs00341g
36
Wu H. Xiao T. (2020). Supramolecular polymers with AIE property fabricated from a Cyanostilbene Motif-derived Ditopic Benzo-21-crown-7 and a Ditopic Dialkylammonium Salt. Front. Chem.8, 610093. 10.3389/fchem.2020.610093
37
Wu J. R. Wu G. Yang Y. W. (2022). Pillararene-inspired macrocycles: From Extended pillar[n]arenes to Geminiarenes. Acc. Chem. Res.55, 3191–3204. 10.1021/acs.accounts.2c00555
38
Xiao T. Chen D. Qian H. Shen Y. Zhang L. Li Z.-Y. et al (2023). Pillar[5]arene-based light-harvesting assemblies with sequential energy-transfer for tunable emission and photocatalysis. Dyes Pigments210, 110958. 10.1016/j.dyepig.2022.110958
39
Xiao T. Elmes R. Yao Y. (2020). Editorial: Host-Guest chemistry of macrocycles. Front. Chem.8, 628200. 10.3389/fchem.2020.628200
40
Xiao T. Qi L. Zhong W. Lin C. Wang R. Wang L. (2019). Stimuli-responsive nanocarriers constructed from pillar[n]arene-based supra-amphiphiles. Mater. Chem. Front.3, 1973–1993. 10.1039/c9qm00428a
41
Xiao T. Qian H. Shen Y. Wei C. Ren D. Zhang L. et al (2022). A tunable artificial light-harvesting system based on host-guest interaction exhibiting ultrahigh antenna effect and narrowed emission band. Mater. Today Chem.24, 100833. 10.1016/j.mtchem.2022.100833
42
Xiao T. Xu L. Zhong W. Zhou L. Sun X.-Q. Hu X.-Y. et al (2018). Advanced Functional materials constructed from pillar[n]arenes. Isr. J. Chem.0, 1219–1229. 10.1002/ijch.201800026
43
Xiao T. Xu L. Zhou L. Sun X.-Q. Lin C. Wang L. (2019). Dynamic hydrogels mediated by macrocyclic host–guest interactions. J. Mater. Chem. B7, 1526–1540. 10.1039/C8TB02339E
44
Xiao T. Zhong W. Xu L. Sun X.-Q. Hu X.-Y. Wang L. (2019). Supramolecular vesicles based on pillar[n]arenes: Design, construction, and applications. Supramol. vesicles based pillar[n]arenes Des. Constr. Appl. Org. Biomol. Chem.17, 1336–1350. 10.1039/C8OB03095B
45
Xiao T. Zhong W. Zhou L. Xu L. Sun X.-Q. Elmes R. B. P. et al (2019). Artificial light-harvesting systems fabricated by supramolecular host–guest interactions. Chin. Chem. Lett.30, 31–36. 10.1016/j.cclet.2018.05.034
46
Xiao T. Zhou L. Sun X.-Q. Huang F. Lin C. Wang L. (2020). Supramolecular polymers fabricated by orthogonal self-assembly based on multiple hydrogen bonding and macrocyclic host–guest interactions. Chin. Chem. Lett.31, 1–9. 10.1016/j.cclet.2019.05.011
47
Xiao T. Zhou L. Xu L. Zhong W. Zhao W. Sun X.-Q. et al (2019). Dynamic materials fabricated from water soluble pillar[n]arenes bearing triethylene oxide groups. Chin. Chem. Lett.30, 271–276. 10.1016/j.cclet.2018.05.039
48
Xue M. Yang Y. Chi X. Zhang Z. Huang F. (2012). Pillararenes, A new Class of macrocycles for supramolecular chemistry. Acc. Chem. Res.45, 1294–1308. 10.1021/ar2003418
49
Zhang Z. Y. Li C. (2022). Biphen[n]arenes: Modular synthesis, Customizable cavity Sizes, and Diverse Skeletons. Acc. Chem. Res.55, 916–929. 10.1021/acs.accounts.2c00043
50
Zhu Y. Chen T. Cui Z. (2022). Multiple Pickering emulsions stabilized by the same particles with different extent of hydrophobization in situ. Front. Chem.10, 950932. 10.3389/fchem.2022.950932
Summary
Keywords
host-guest chemistry, macrocyclic molecules, supramolecular self-assembly, pillar[n]arenes, cucurbit[n]urils
Citation
Xiao T, Elmes R and Yao Y (2023) Editorial: Host–guest chemistry of macrocycles— Volume II. Front. Chem. 11:1162019. doi: 10.3389/fchem.2023.1162019
Received
09 February 2023
Accepted
14 February 2023
Published
21 February 2023
Volume
11 - 2023
Edited and reviewed by
Tony D. James, University of Bath, United Kingdom
Updates
Copyright
© 2023 Xiao, Elmes and Yao.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Tangxin Xiao, xiaotangxin@cczu.edu.cn; Robert Elmes, robert.elmes@mu.ie; Yong Yao, yaoyong1986@ntu.edu.cn
This article was submitted to Supramolecular Chemistry, a section of the journal Frontiers in Chemistry
Disclaimer
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.