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  • Article
  • Open Access
18 Citations
8,878 Views
12 Pages

Structural Study of Mismatched Disila-Crown Ether Complexes

  • Kirsten Reuter,
  • Fabian Dankert,
  • Carsten Donsbach and
  • Carsten Von Hänisch

Mismatched complexes of the alkali metals cations Li+ and Na+ were synthesized from 1,2-disila[18]crown-6 (1 and 2) and of K+ from 1,2,4,5-tetrasila[18]crown-6 (4). In these alkali metal complexes, not all crown ether O atoms participate in the coord...

  • Article
  • Open Access
3 Citations
2,639 Views
12 Pages

12 June 2023

Positively charged metal–ammonia complexes are known to host peripheral, diffuse electrons around their molecular skeleton. The resulting neutral species form materials known as expanded or liquid metals. Alkali, alkaline earth, and transition...

  • Communication
  • Open Access
2,656 Views
6 Pages

Synthesis and Structural Analysis of a Nitrobenzofurazan Derivative of Dibenzo-18-Crown-6 Ether

  • Alexandru Bujor,
  • Victorita Tecuceanu,
  • Anamaria Hanganu and
  • Petre Ionita

9 December 2022

Nitrobenzofurazan derivatives are well known for their fluorescence, whilst crown ethers are known for their complexing capacity toward cationic species. In this study, we present the synthesis and structural characterization of a new derivative cont...

  • Article
  • Open Access
4,219 Views
17 Pages

The Structure and Location of 18-Crown-6 Ether in Zeolites RHO and ZK-5

  • Antony Nearchou,
  • Catherine Dejoie,
  • Paul R. Raithby and
  • Asel Sartbaeva

13 March 2022

The use of organic additives presents the greatest versatility and control of zeolite synthesis in order to prepare novel architectures for desired applications. Despite this prospect, there is little clarity of how organic additives are involved in...

  • Article
  • Open Access
2 Citations
1,404 Views
20 Pages

Crown Ether-Functionalized Polyethersulfone Membranes with Potential Applications in Hemodialysis

  • Madalina Oprea,
  • Andreea Madalina Pandele,
  • Catalin Ionel Enachescu,
  • Iulian Vasile Antoniac,
  • Stefan Ioan Voicu and
  • Anca Maria Fratila

9 August 2025

Polyethersulfone (PES) is one of the most used synthetic polymers for the production of hemodialysis membranes, due to its appropriate features, such as biocompatibility, high permeability for low-molecular-weight proteins, high endotoxin retention a...

  • Article
  • Open Access
7 Citations
3,638 Views
7 Pages

Inter- and Intra-Molecular Organocatalysis of SN2 Fluorination by Crown Ether: Kinetics and Quantum Chemical Analysis

  • Young-Ho Oh,
  • Wonhyuck Yun,
  • Chul-Hee Kim,
  • Sung-Woo Jang,
  • Sung-Sik Lee,
  • Sungyul Lee and
  • Dong-Wook Kim

We present the intra- and inter-molecular organocatalysis of SN2 fluorination using CsF by crown ether to estimate the efficacy of the promoter and to elucidate the reaction mechanism. The yields of intramolecular SN2 fluorination of the veratrole su...

  • Article
  • Open Access
11 Citations
3,224 Views
15 Pages

Novel Crown Ether Amino Acids as Fluorescent Reporters for Metal Ions

  • Patrícia M. R. Batista,
  • Cátia D. F. Martins,
  • M. Manuela M. Raposo and
  • Susana P. G. Costa

Unnatural amino acids with enhanced properties, such as increased complexing ability and luminescence, are considered to be highly attractive building blocks for bioinspired frameworks, such as probes for biomolecule dynamics, sensitive fluorescent c...

  • Article
  • Open Access
7 Citations
9,602 Views
6 Pages

Synthesis of a Novel D-Glucose-Conjugated 15-Crown-5 Ether with a Spiro Ketal Structure

  • Takashi Yamanoi,
  • Yoshiki Oda,
  • Hitomi Muraishi and
  • Sho Matsuda

22 August 2008

This paper describes a synthetic approach to a novel D-glucose-conjugated 15-crown-5 ether having a spiroketal structure starting from a 1-C-vinylated glucose derivative. The approach consists of the glycosylation of the vinylated glucose derivative...

  • Article
  • Open Access
23 Citations
2,795 Views
16 Pages

Evaluation of Performance of Functionalized Amberlite XAD7 with Dibenzo-18-Crown Ether-6 for Palladium Recovery

  • Oana Alexandra Grad,
  • Mihaela Ciopec,
  • Adina Negrea,
  • Narcis Duteanu,
  • Petru Negrea and
  • Raluca Vodă

20 February 2021

Due to the increased demand for palladium, as well due to its reduced availability in nature, its recovery from diluted waste solutions becomes a necessity, and perhaps an emergency. As a result of economic and technological development, new material...

  • Article
  • Open Access
3 Citations
2,059 Views
16 Pages

The large-scale application of aromatic polyamide (PA) thin-film composite (TFC) membranes for reverse osmosis has provided an effective way to address worldwide water scarcity. However, the water permeability and salt rejection capabilities of the P...

  • Article
  • Open Access
12 Citations
3,906 Views
16 Pages

Achiral Molecular Recognition of Substituted Aniline Position Isomers by Crown Ether Type Chiral Stationary Phase

  • Atsushi Ohnishi,
  • Tohru Shibata,
  • Tatsuya Imase,
  • Satoshi Shinkura and
  • Kanji Nagai

18 January 2021

To understand the selectivity of the crown ether type chiral stationary phase (CSP), the retention selectivity for aniline and the positional isomers of substituted anilines were studied. In various substituted isomers, except nitroaniline, a remarka...

  • Article
  • Open Access
1,711 Views
21 Pages

Thorium Recovery with Crown Ether–Polymer Composite Membranes

  • Aurelia Cristina Nechifor,
  • Paul Constantin Albu,
  • Ludmila Motelica,
  • Geani Teodor Man,
  • Alexandra Raluca Grosu,
  • Szidonia-Katalin Tanczos,
  • Vlad-Alexandru Grosu,
  • Virgil Emanuel Marinescu and
  • Gheorghe Nechifor

30 October 2024

Thorium is a weak radioactive element, but the control of its concentration in natural aqueous systems is of great interest for health, because it is a toxic heavy metal. The present paper presents the recovery of thorium from diluted synthetic aqueo...

  • Article
  • Open Access
33 Citations
12,068 Views
10 Pages

4 April 2011

Arginine plays an important role in cell division and the functioning of the immune system. We describe a novel method by which arginine can be identified using an artificial monolayer based on surface plasmon resonance (SPR). The affinity of arginin...

  • Article
  • Open Access
1 Citations
2,237 Views
23 Pages

12 June 2025

Aza-crown ether structures have been proven to be effective in constructing fluorescent biosensors for selectively detecting and imaging alkali metal ions in biological environments. However, choosing the right aza-crown ether for a specific alkali m...

  • Feature Paper
  • Article
  • Open Access
20 Citations
6,571 Views
19 Pages

Improved Electronic Transport in Ion Complexes of Crown Ether Based Columnar Liquid Crystals

  • Peter Staffeld,
  • Martin Kaller,
  • Philipp Ehni,
  • Max Ebert,
  • Sabine Laschat and
  • Frank Giesselmann

31 January 2019

The Li+- and K+-complexes of new discotic mesogens, where two n-alkoxy-substituted triphenylene cores are connected by a central crown ether (12-crown-4 and 18-crown-6), provide interesting structural and electronic properties. The inter- and intra-c...

  • Article
  • Open Access
3 Citations
2,421 Views
19 Pages

Because of environmental impact, there is a great need for chemosensors, especially for toxic heavy metals such as lead. The conventional instrumental analytical techniques rarely provide an available real-time sensing platform, thus the development...

  • Article
  • Open Access
4 Citations
2,329 Views
22 Pages

22 December 2024

Direct lithium extraction from unconventional resources requires the development of effective adsorbents. Crown ether-containing materials have been reported as promising structures in terms of lithium selectivity, but data on adsorption in real, hig...

  • Article
  • Open Access
1,383 Views
22 Pages

Crown ethers have gained importance in the field of medicine because of their resemblance to natural ionophores like valinomycin. With the goal of developing new pharmacologically important crown ethers, a novel series of crown ethers linked with Fus...

  • Article
  • Open Access
6 Citations
4,265 Views
15 Pages

K+-Responsive Crown Ether-Based Amphiphilic Copolymer: Synthesis and Application in the Release of Drugs and Au Nanoparticles

  • Xiao Wang,
  • Xianghong Zheng,
  • Xinyu Liu,
  • Birong Zeng,
  • Yiting Xu,
  • Conghui Yuan and
  • Lizong Dai

20 January 2022

Due to unique chelating and macrocyclic effects, crown ether compounds exhibit wide application prospects. They could be introduced into amphiphilic copolymers to provide new trigger mode for drug delivery. In this work, new amphiphilic random polyme...

  • Article
  • Open Access
1 Citations
2,057 Views
19 Pages

10 November 2023

A crown ether-loaded hybrid adsorbent suitable for the separation and enrichment of strontium from high-level liquid waste was synthesized. 4′,4′(5″)-di(tert-butylcyclohexano)-18-crown-6 (DtBuCH18C6) and its modifiers dodecyl benzen...

  • Article
  • Open Access
11 Citations
3,411 Views
14 Pages

Crown Ether-Immobilized Cellulose Acetate Membranes for the Retention of Gd (III)

  • Oana Steluta Serbanescu,
  • Andreea Madalina Pandele,
  • Madalina Oprea,
  • Augustin Semenescu,
  • Vijay Kumar Thakur and
  • Stefan Ioan Voicu

17 November 2021

This study presents a new, revolutionary, and easy method of separating Gd (III). For this purpose, a cellulose acetate membrane surface was modified in three steps, as follows: firstly, with aminopropyl triethoxysylene; then with glutaraldehyde; and...

  • Article
  • Open Access
314 Views
22 Pages

Molecularly Engineered Aza-Crown Ether Functionalized Sodium Alginate Aerogels for Highly Selective and Sustainable Cu2+ Removal

  • Teng Long,
  • Ayoub El Idrissi,
  • Lin Fu,
  • Yufan Liu,
  • Banlian Ruan,
  • Minghong Ma,
  • Zhongxun Li and
  • Lingbin Lu

16 January 2026

Developing sustainable and molecularly selective adsorbents for heavy-metal removal remains a critical challenge in water purification. Herein, we report a green molecular-engineering approach for fabricating aza-crown ether functionalized sodium alg...

  • Article
  • Open Access
2,008 Views
22 Pages

A Bis(Acridino)-Crown Ether for Recognizing Oligoamines in Spermine Biosynthesis

  • Péter Kisfaludi,
  • Sára Spátay,
  • Marcell Krekó,
  • Panna Vezse,
  • Tünde Tóth,
  • Péter Huszthy and
  • Ádám Golcs

15 September 2024

Oligoamines in cellular metabolism carry extremely diverse biological functions (i.e., regulating Ca2+-influx, neuronal nitric oxide synthase, membrane potential, Na+, K+-ATPase activity in synaptosomes, etc.). Furthermore, they also act as longevity...

  • Article
  • Open Access
6 Citations
5,278 Views
11 Pages

12 August 2019

In this manuscript, we present the successful attachment of crown ether moieties onto fluoropolymer surfaces, via the combination of radiation-induced graft polymerization and a subsequent surface Kabachnik–Fields three-component reaction. The...

  • Article
  • Open Access
12 Citations
5,210 Views
16 Pages

28 February 2023

A silica-supported copper (Cu/SiO2) catalyst containing highly dispersed Cu nanoparticles was prepared via a crown-ether-assisted impregnation method. A 12-crown-4-ether-assisted Cu/SiO2 catalyst outperformed several Cu/SiO2 catalysts prepared with v...

  • Communication
  • Open Access
1,133 Views
9 Pages

Hybrid Crown Ether Ligands with Disiloxane Units and Their Complexes with Small s-Block Ions

  • Roman-Malte Richter,
  • Daniel James Stauf,
  • Anna Lena Rauchel,
  • Lutz Ruppach,
  • Kevin Bania,
  • Annalena Duncker and
  • Carsten von Hänisch

Herein, we present hybrid crown ether ligands with siloxane and ethylene oxide units and their coordination with the cations Li+, Na+, Mg2+ and Ca2+. The compounds prepared are (SiMe2O)2(C2H4O)3 (1, TrEGDS = Triethylenglycoldisiloxane) and (SiMe2O)2(...

  • Article
  • Open Access
36 Citations
6,459 Views
12 Pages

Crown-Ether Functionalized Graphene Oxide Membrane for Lithium Recovery from Water

  • Luisa Baudino,
  • Alessandro Pedico,
  • Stefano Bianco,
  • Monica Periolatto,
  • Candido Fabrizio Pirri and
  • Andrea Lamberti

18 February 2022

The massive worldwide transition of the transport sector to electric vehicles has dramatically increased the demand for lithium. Lithium recovery by means of ion sieves or supramolecular chemistry has been extensively studied in recent years as a via...

  • Article
  • Open Access
4 Citations
2,069 Views
16 Pages

The aim of the work was to analyze the preferential solvation process, and determine the composition of the solvation shell of cyclic ethers using the calorimetric method. The heat of solution of 1,4-dioxane, 12-crown-4, 15-crown-5 and 18-crown-6 eth...

  • Article
  • Open Access
10 Citations
5,226 Views
20 Pages

2 September 2024

The challenge of efficiently extracting Li+ from brines with high Na+ or Mg2+ concentrations has led to extensive research on developing highly selective separation membranes for electrodialysis. Various studies have demonstrated that nanofiltration...

  • Article
  • Open Access
10 Citations
3,192 Views
14 Pages

Covalently Immobilizable Tris(Pyridino)-Crown Ether for Separation of Amines Based on Their Degree of Substitution

  • Panna Vezse,
  • Bianka Benda,
  • András Fekete,
  • Ádám Golcs,
  • Tünde Tóth and
  • Péter Huszthy

29 April 2022

A great number of biologically active compounds contain at least one amine function. Appropriate selectivity can only be accomplished in a few cases upon the substitution of these groups, thus functionalization of amines generally results in a mixtur...

  • Article
  • Open Access
11 Citations
8,523 Views
7 Pages

31 August 2001

New podand and crown ether derivatives of 3,5-disubstituted 4H-pyran-4-one (8-11) were prepared by the nucleophilic substitution reaction of 3,5-bis(bromomethyl)-2,6-diphenyl-4H-pyran-4-one with o-nitrophenol, 8-hydroxyquinoline, 2-hydroxymethyl pyri...

  • Letter
  • Open Access
5 Citations
3,404 Views
8 Pages

Beryllium-Ion-Selective PEDOT Solid Contact Electrode Based on 9,10-Dinitrobenzo-9-Crown-3-Ether

  • Junghwan Kim,
  • Dae Hee Kim,
  • Jin Cheol Yang,
  • Jae Sang Kim,
  • Ji Ha Lee and
  • Sung Ho Jung

9 November 2020

A beryllium(II)-ion-selective poly(ethylenedioxythiophene) (PEDOT) solid contact electrode comprising 9,10-dinitrobenzo-9-crown-3-ether was successfully developed. The all-solid-state contact electrode, with an oxygen-containing cation-sensing membra...

  • Article
  • Open Access
13 Citations
4,332 Views
18 Pages

Study of Lithium-Extraction Systems Based on Benzo-15-Crown-5 Ether and Alkylimidazolium-Based Ionic Liquid

  • Alexey A. Bezdomnikov,
  • Liudmila I. Demina,
  • Lyudmila G. Kuz’mina,
  • Galina V. Kostikova,
  • Valeriy I. Zhilov and
  • Aslan Yu. Tsivadze

17 January 2023

The extraction of lithium from aqueous solutions of LiNTf2 and LiCl salts using benzo-15-crown-5 ether (B15C5) as an extractant in [C8mim][NTf2] ionic liquid was studied. The transition of the extractant into the aqueous phase and the distribution of...

  • Article
  • Open Access
28 Citations
5,699 Views
14 Pages

3 May 2018

Lead is a particularly toxic heavy metal that is present above acceptable levels in the water of many countries. This article describes a quick detection method of lead(II) ions using a polyvinyl chloride (PVC)-based ion-selective membrane electrode...

  • Article
  • Open Access
10 Citations
5,292 Views
15 Pages

10 June 2021

A series of CO2-selective polyimides (CE-PDMS-PI-x) was synthesized by copolymerizing crown ether diamine (trans-diamino-DB18C6) and PDMS-diamine with 4,4′-(hexafluoroisopropylidene) di-phthalic anhydride (6FDA) through the polycondensation reaction....

  • Article
  • Open Access
6 Citations
2,008 Views
14 Pages

26 February 2023

The solution enthalpy of 15-crown-5 and 18-crown-6 ethers in the mixture of formamide (F) and water (W) was measured at four temperatures: 293.15 K, 298.15 K, 303.15 K, 308.15 K. The standard molar enthalpy of solution, ΔsolHo, depends on the s...

  • Article
  • Open Access
2 Citations
3,526 Views
17 Pages

Grafting of Crown Ether and Cryptand Macrocycles on Large Pore Stellate Mesoporous Silica for Sodium Cation Extraction

  • Paula Duenas-Ramirez,
  • Caroline Bertagnolli,
  • Robin Weiss,
  • Joëlle Bizeau,
  • Loïc Jierry,
  • Philippe Choquet,
  • Ariane Zaloszyc,
  • Sylvie Bégin-Colin and
  • Damien Mertz

Regulation of the sodium cations level in the case of renal failure diseases is a very challenging task for clinicians, and new pollutant extractors based on nanomaterials are emerging as potential treatments. In this work, we report different strate...

  • Article
  • Open Access
1 Citations
1,594 Views
13 Pages

14 November 2023

A novel hydrogen-bonded supramolecular crown-ether-based inclusion compound, [(DL-α-Phenylglycine)(18-crown-6)]+[(CoCl4)0.5](1), was obtained via evaporation in a methanolic solution at room temperature using DL-α-phenylglycine, 18...

  • Article
  • Open Access
4 Citations
2,424 Views
14 Pages

Crown Ether Copolymerized Polyimide Film: Enhanced Mechanical, Thermal Properties and Low Dielectric Constant under High Frequency

  • Heming Li,
  • Xinming Wang,
  • Ziyang Ding,
  • Weiguo Gao,
  • Yan Liu,
  • Ke Ma,
  • Zhizhi Hu and
  • Yongqi Wang

24 April 2024

Polymer materials with a low dielectric constant and low dielectric loss have the potential to be applied to high-frequency signal transmissions, such as mobile phone antennas and millimeter wave radars. Two types of diamines, 4,4′-diamino-p-te...

  • Article
  • Open Access
37 Citations
10,908 Views
12 Pages

6 September 2010

Microwave irradiation was used to obtain a di-Schiff base type crosslinked chitosan dibenzocrown ether (CCdBE) via the reaction between the –NH2 and –CHO groups in chitosan and 4,4′-diformyldibenzo-18-c-6, respectively. The structure of the synthesiz...

  • Article
  • Open Access
31 Citations
4,781 Views
14 Pages

11 October 2021

Nanofiber membranes were successfully prepared with crown ether (CE) functionalized graphene oxide (GO), chitosan (CS), and polyvinyl alcohol (PVA) by low-temperature thermally induced liquid–liquid phase separation. The physical and chemical propert...

  • Article
  • Open Access
184 Views
21 Pages

Potassium Hexafluoroacetylacetonate Complex with 18-Crown-6 Ether as a Volatile Precursor of Molecular and Inorganic Films: Thermal and Structural Insights

  • Danil V. Kochelakov,
  • Evgeniia S. Vikulova,
  • Dina B. Kayumova,
  • Irina P. Malkerova,
  • Natalia V. Kuratieva,
  • Ilya V. Korolkov,
  • Nikolay B. Kompan’kov,
  • Darya D. Klyamer,
  • Andrey S. Alikhanyan and
  • Sergey A. Gromilov

25 February 2026

Volatile coordination compounds are widely used as precursors for the gas phase synthesis of functional materials. However, such complexes are still very rare for alkali metals, especially for heavy representatives of this family (potassium, rubidium...

  • Article
  • Open Access
4 Citations
4,163 Views
16 Pages

Extraction of Pb(II) with picrate ion [Pic] and 0, 0.58, 15, 48, or 97 mmol·dm−3 Cd(NO3)2 by benzo-18-crown-6 ether (B18C6; L as its symbol) into benzene (Bz) was studied. Three kinds of extraction constants, Kex, Kex±, and...

  • Article
  • Open Access
2 Citations
2,523 Views
17 Pages

13 April 2023

Modifying non-precious metal porphyrins at the meso-position is sufficient to further improve the ability to activate O2 and the selectivity of the corresponding redox products. In this study, a crown ether-appended Fe(III) porphyrin complex (FeTC4PC...

  • Article
  • Open Access
5 Citations
5,161 Views
16 Pages

Extraction constants (Kex & Kex±) for the extraction of silver picrate (AgPic) by benzo-18-crown-6 ether (B18C6) into 1,2-dichloroethane (DCE) were determined at 298 K and various ionic strength (I)-values of a water phase with or without excess...

  • Article
  • Open Access
4 Citations
1,535 Views
17 Pages

28 November 2024

Crown ether is widely used in water purification because of its ring structure and good selective adsorption of specific heavy metals. However, its high cost and difficulty in recycling limit the purification of heavy metals in water. The anisotropic...

  • Article
  • Open Access
947 Views
9 Pages

Ultra-Weak Photon Emission from Crown Ethers Exposed to Fenton’s Reagent Fe2+-H2O2

  • Michał Nowak,
  • Krzysztof Sasak,
  • Anna Wlodarczyk,
  • Izabela Grabska-Kobylecka,
  • Agata Sarniak and
  • Dariusz Nowak

5 August 2025

We hypothesized that compounds containing ether linkages within their backbone structures, when exposed to hydroxyl radicals (•OH), can generate ultra-weak photon emission (UPE) as a result of the formation of triplet excited carbonyl species (3...

  • Article
  • Open Access
1 Citations
2,358 Views
17 Pages

The Effect of Ca, Sr, and Ba Chloride Complexes with Dibenzo-18-Crown-6 Ether as Catalysts on the Process Criteria for the Efficiency of Cumene Oxidation (the First Stage in the Chain of Polymer Composite Production)

  • Nikolai V. Ulitin,
  • Nikolay A. Novikov,
  • Yana L. Lyulinskaya,
  • Daria A. Shiyan,
  • Konstantin A. Tereshchenko,
  • Natalia M. Nurullina,
  • Marina N. Denisova,
  • Yaroslav O. Mezhuev and
  • Kharlampii E. Kharlampidi

6 February 2023

A study was made on the effect of Ca, Sr, and Ba chloride complexes with dibenzo-18-crown-6 ether as catalysts on the process criteria of the efficiency of industrial cumene oxidation using kinetic modeling. It is the first stage in the process chain...

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