Submit to Special Issue Submit Abstract to Special Issue Review for Molecules Edit a Special Issue

Journal Menu

Journal Browser

► Journal Browser

Special Issue "Calixarene Complexes: Synthesis, Properties and Applications II"

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Published Papers

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Organic Chemistry".

Deadline for manuscript submissions: 30 November 2023 | Viewed by 5061

Share This Special Issue

Special Issue Editor

Prof. Dr. Paula M. Marcos

E-Mail Website
Guest Editor

1. CQE – Centro de Química Estrutural, Faculdade de Ciências da Universidade de Lisboa, Edifício C8, 1749-016 Lisboa, Portugal
2. Faculdade de Farmácia da Universidade de Lisboa, 1649-003 Lisboa, Portugal
Interests: macrocyclic and supramolecular chemistry; calixarenes; host-guest chemistry; ion binding; organic ion-pair recognition; NMR and UV-Vis absorption spectroscopy
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Ion recognition continues to attract the interest of researchers all over the world, due to the important role that cations and anions play in biological and chemical systems, and in the environment. Calixarenes, owing to their structural features, are one of the most widely studied supramolecular hosts. They possess a well-defined hydrophobic cavity available in different sizes and conformations, and an almost unlimited number of derivatives can be obtained by functionalization of their upper and lower rims. These macrocyclic compounds have been largely exploited as ionic and neutral molecule receptors, and present an increasing number of applications in different fields, such as organocatalysis, sensing, extraction and separation, and recently in biomedicine. Due to the high participation of the scientific community in the previous Special Issue, we decided to continue this topic. Thus, the second Issue of Calixarene Complexes: Synthesis, Properties and Applications aims to update the host–guest chemistry of calixarenes and related compounds, showing their most recent properties and applications, as well as progresses in their syntheses. Research and review articles on topics related to this field are welcome.

Prof. Dr. Paula M. Marcos
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2300 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (6 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

Open AccessArticle

Critical Analysis of Association Constants between Calixarenes and Nitroaromatic Compounds Obtained by Fluorescence. Implications for Explosives Sensing

Alexandre S. Miranda

Paula M. Marcos

José R. Ascenso

Mário N. Berberan-Santos

Peter J. Cragg

Rachel Schurhammer

and

Christophe Gourlaouen

Molecules 2023, 28(7), 3052; https://doi.org/10.3390/molecules28073052 - 29 Mar 2023

Viewed by 539

Abstract

The binding behaviour of two ureido-hexahomotrioxacalix[3]arene derivatives bearing naphthyl (1) and pyrenyl (2) fluorogenic units at the lower rim towards selected nitroaromatic compounds (NACs) was evaluated. Their affinity, or lack of it, was determined by UV-Vis absorption, fluorescence and NMR spectroscopy. Different computational methods were also used to further investigate any possible complexation between the calixarenes and the NACs. All the results show no significant interaction between calixarenes 1 and 2 and the NACs in either dichloromethane or acetonitrile solutions. Moreover, the fluorescence quenching observed is only apparent and merely results from the absorption of the NACs at the excitation wavelength (inner filter effect). This evidence is in stark contrast with reports in the literature for similar calixarenes. A naphthyl urea dihomooxacalix[4]arene (3) is also subject to the inner filter effect and is shown to form a stable complex with trinitrophenol; however, the equilibrium association constant is greatly overestimated if no correction is applied (9400 M⁻¹ vs 3000 M⁻¹), again stressing the importance of taking into account the inner filter effect in these systems. Full article

(This article belongs to the Special Issue Calixarene Complexes: Synthesis, Properties and Applications II)

► Show Figures

Figure 1

Open AccessArticle

Calix[4]arene Derivative for Iodine Capture and Effect on Leaching of Iodine through Packaging

Grazia Maria Letizia Consoli

Paola Rizzarelli

and

Emanuela Teresa Agata Spina

Molecules 2023, 28(4), 1869; https://doi.org/10.3390/molecules28041869 - 16 Feb 2023

Viewed by 786

Abstract

A hydrophobic calix[4]arene derivative was investigated for its iodine (I₂) capture efficiency from gaseous and liquid phase. The iodine uptake was followed by UV-vis spectroscopy. Additionally, the influence of the calix[4]arene derivative–polyolefin system on the leaching of iodine through packaging from a povidone-iodine-based (PVP-I) formulation was evaluated. In fact, iodine is a low-cost, multi-target, and broad-spectrum antiseptic. However, it is volatile, and the extended storage of I₂-based formulations is challenging in plastic packaging. Here, we investigated the possibility of reducing the loss of I₂ from an iodophor formulation by incorporating 4-tert-butylcalix [4]arene-tetraacetic acid tetraethyl ester (CX) and its iodine complex in high-density polyethylene (HDPE) or polypropylene (PP) via a swelling procedure. Surface and bulk changes were monitored by contact angle, thermogravimetric analysis (TGA), and UV-vis diffuse reflectance spectra. The barrier effect of the different polymeric systems (embedded with CX, iodine-CX complex, or I2) was evaluated by monitoring the I2 retention in a buffered PVP-I solution by UV-vis spectroscopy. Overall, experimental data showed the capability of the calix[4]arene derivative to complex iodine in solution and the solid state and a significant reduction in the iodine leaching by the PP-CX systems. Full article

(This article belongs to the Special Issue Calixarene Complexes: Synthesis, Properties and Applications II)

► Show Figures

Graphical abstract

Open AccessArticle

New Supramolecular Hypoxia-Sensitive Complexes Based on Azo-Thiacalixarene

and

Molecules 2023, 28(2), 466; https://doi.org/10.3390/molecules28020466 - 04 Jan 2023

Viewed by 677

Abstract

Hypoxia accompanies many human diseases and is an indicator of tumor aggressiveness. Therefore, measuring hypoxia in vivo is clinically important. Recently, complexes of calix[4]arene were identified as potent hypoxia markers. The subject of this paper is new hypoxia-sensitive host–guest complexes of thiacalix[4]arene. We report a new high-yield synthesis method for thiacalix[4]arene with four anionic carboxyl azo fragments on the upper rim (thiacalixarene L) and an assessment of the complexes of thiacalixarene L with the most widespread cationic rhodamine dyes (6G, B, and 123) sensitivity to hypoxia. Moreover, 1D and 2D NMR spectroscopy data support the ability of the macrocycles to form complexes with dyes. Rhodamines B and 123 formed host–guest complexes of 1:1 stoichiometry. Complexes of mixed composition were formed with rhodamine 6G. The association constant between thiacalixarene L and rhodamine 6G is higher than for other dyes. Thiacalixarene L-dye complexes with rhodamine 6G and rhodamine B are stable in the presence of various substances present in a biological environment. The UV-VIS spectrometry and fluorescence showed hypoxia responsiveness of the complexes. Our results demonstrate that thiacalixarene L has a stronger binding with dyes compared with the previously reported azo-calix[4]arene carboxylic derivative. Thus, these results suggest higher selective visualization of hypoxia for the complexes with thiacalixarene L. Full article

(This article belongs to the Special Issue Calixarene Complexes: Synthesis, Properties and Applications II)

► Show Figures

Figure 1

Open AccessArticle

The Formation of Inherently Chiral Calix[4]quinolines by Doebner–Miller Reaction of Aldehydes and Aminocalixarenes

and

Molecules 2022, 27(23), 8545; https://doi.org/10.3390/molecules27238545 - 04 Dec 2022

Cited by 1 | Viewed by 907

Abstract

The formation of inherently chiral calix[4]arenes by the intramolecular cyclization approach suffers from a limited number of suitable substrates for these reactions. Here, we report an easy way to prepare one class of such compounds: calixquinolines, which can be obtained by the reaction of aldehydes with easily accessible aminocalix[4]arenes in acidic conditions (Doebner–Miller reaction). The synthetic procedure represents a very straightforward approach to the inherently chiral macrocyclic systems. The complexation studies revealed the ability of these compounds to complex quaternary ammonium salts with different stoichiometries depending on the guest molecules. At the same time, the ability of enantioselective complexation of chiral N-methylammonium salts was demonstrated. Full article

(This article belongs to the Special Issue Calixarene Complexes: Synthesis, Properties and Applications II)

► Show Figures

Figure 1

Open AccessArticle

Electronic Tuning of Host-Guest Interactions within the Cavities of Fluorophore-Appended Calix[4]arenes

Varun Rawat

and

Arkadi Vigalok

Molecules 2022, 27(17), 5689; https://doi.org/10.3390/molecules27175689 - 03 Sep 2022

Viewed by 713

Abstract

A series of fluorescent calix[4]arene scaffolds bearing electron-rich carbazole moiety conjugated at the lower rim have been prepared. Studies of the fluorescence quenching in the presence of the N-methyl pyridinium guest revealed that the electronic properties of the distal phenolic ring play a major role in the host–guest complexation. In particular, placing an electron-donating piperidine fragment at that ring significantly increased the host–guest interactions, while introducing the same fragment into the proximal phenolic ring weakened the fluorescence response. These results suggest that the dominant interactions between the guest and calixarene cavity involve the oxygen-depleted fluorophore-bearing aromatic ring and not the more electron-rich unsubstituted phenolic fragments. Full article

(This article belongs to the Special Issue Calixarene Complexes: Synthesis, Properties and Applications II)

► Show Figures

Graphical abstract

Open AccessArticle

Anion Binding by Fluorescent Ureido-Hexahomotrioxacalix[3]arene Receptors: An NMR, Absorption and Emission Spectroscopic Study

Alexandre S. Miranda

Paula M. Marcos

José R. Ascenso

Mário N. Berberan-Santos

and

Filipe Menezes

Molecules 2022, 27(10), 3247; https://doi.org/10.3390/molecules27103247 - 19 May 2022

Cited by 1 | Viewed by 979

Abstract

Fluorescent receptors (4a–4c) based on (thio)ureido-functionalized hexahomotrioxacalix[3]arenes were synthesised and obtained in the partial cone conformation in solution. Naphthyl or pyrenyl fluorogenic units were introduced at the lower rim of the calixarene skeleton via a butyl spacer. The binding of biologically and environmentally relevant anions was studied with NMR, UV–vis absorption, and fluorescence titrations. Fluorescence of the pyrenyl receptor 4c displays both monomer and excimer fluorescence. The thermodynamics of complexation was determined in acetonitrile and was entropy-driven. Computational studies were also performed to bring further insight into the binding process. The data showed that association constants increase with the anion basicity, and AcO⁻, BzO⁻ and F⁻ were the best bound anions for all receptors. Pyrenylurea 4c is a slightly better receptor than naphthylurea 4a, and both are more efficient than naphthyl thiourea 4b. In addition, ureas 4a and 4c were also tested as ditopic receptors in the recognition of alkylammonium salts. Full article

(This article belongs to the Special Issue Calixarene Complexes: Synthesis, Properties and Applications II)

► Show Figures

Journal Menu

Journal Browser

Special Issue "Calixarene Complexes: Synthesis, Properties and Applications II"

Share This Special Issue

Special Issue Editor

Special Issue Information

Published Papers (6 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI