Design of lithium selective crown ethers: Synthesis, extraction and theoretical binding studies

Torrejos, Rey Eliseo C.; Nisola, Grace M.; Song, Ho Seong; Limjuco, Lawrence A.; Lawagon, Chosel P.; Parohinog, Khino J.; Koo, Sangho; Han, Jeong Woo; Chung, Wook–Jin

doi:10.1016/j.cej.2017.06.005

Cited by 96 publications

(61 citation statements)

References 50 publications

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“…Initial cyclization reactions were done in different solvents, catalysts and templates (Table S1 in the Supporting Information). From earlier report, intermolecular cyclization of 1 a with catechol conveniently afforded di‐hydroxy 14–15 membered CE derivatives in high yields (74–92 %) using LiOH as metal template and basic catalyst in t ‐BuOH . However, using the same solvent‐catalyst system did not produce the desired CE 2 a (SI Table S1, Entry 1) nor the replacement of metal templates to NaOH, Mg(OH) 2 or Ca(OH) 2 (SI Table S1, Entries 2–5).…”

Section: Resultsmentioning

confidence: 92%

“…These reactions did not produce the desired cyclic 2 a due to the high solubility of both a and 1 a in polar solvents such as t ‐BuOH, DMSO and DMF. Excessive reactivities of both reactants promoted the formation of linear by‐products . Previously, CE cyclization of catechol with 1 a was achieved by limiting the solubility of one of the reactants.…”

Section: Resultsmentioning

confidence: 99%

“…Crown ethers (CEs) are cyclic ligands known for their high affinity and specificity towards certain cations according to cavity size‐match selectivity making them ideal PGM sequestrants ,. Moreover, CEs with mixed oxygen, nitrogen, and sulfur (O,N,S) heteroatoms are known to possess strong affinities towards PGMs .…”

Section: Introductionmentioning

confidence: 99%

“…From a previous study, 14–15 membered di‐hydroxy Li + ‐ selective CEs have been efficiently synthesized via intermolecular cyclization of bulky bis‐epoxides with a nucleophile (i. e. catechol) . Cyclization reactions involving bis‐epoxides and catechol have been typically performed in high boiling point solvents like tert ‐Butyl alcohol ( t ‐BuOH), dimethyl sulfoxide (DMSO), dimethylformamide (DMF), and Tetrahydrofuran (THF)‐H 2 O.…”

Section: Introductionmentioning

confidence: 99%

“…Three types of bis‐epoxides ( 1 a – 1 c ) with bulky or rigid sub‐units were recruited. Previously, the bulky sub‐unit of 1 b was proved to be effective in thwarting the complexation of a 14‐membered CE with unwanted cations while preferring Li + . Thus, incorporation of 1 b in O,N,S‐bearing CEs could enhance their selectivity towards PGMs.…”

Section: Introductionmentioning

confidence: 99%

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Aqueous Synthesis of 14‐15‐Membered Crown Ethers with Mixed O, N and S Heteroatoms: Experimental and Theoretical Binding Studies with Platinum‐Group Metals

et al. 2019

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A series of 14‐15‐membered O, N, and S‐containing crown ethers (CEs) was synthesized by cyclization of bis‐epoxides with aryl‐N or S dinucleophiles using triethylamine as a catalyst and LiCl as a metal template in water. The catalyst dosage, and metal template type and dosage were critical in achieving yields of 56–93 %. Liquid‐liquid extraction (LLE) was performed to evaluate the CE complexation with Pd2+ and Pt2+. Among the CEs, a dioxa‐dithia dibenzo CE exhibited the highest Pd2+ selectivity even in the presence of other platinum‐group metals (PGMs). Complementary DFT studies reveal that this CE has the most compatible cavity dimension (ØCE=1.58 Å) with Pd2+ (ØPd2+=1.56 Å) forming a square‐planar S4 geometry. Binding‐energy calculations showed the Pd2+ complex has the least energy requirement for structural reorientation during complexation. Overall results highlight the importance of CE cavity dimension and presence of S heteroatoms for the structural design of CEs selective towards PGMs such as Pd2+.

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Section: Resultsmentioning

confidence: 92%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Aqueous Synthesis of 14‐15‐Membered Crown Ethers with Mixed O, N and S Heteroatoms: Experimental and Theoretical Binding Studies with Platinum‐Group Metals

et al. 2019

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Recent Advances in the Lithium Recovery from Water Resources: From Passive to Electrochemical Methods

et al. 2022

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The ever-increasing amount of batteries used in today's society has led to an increase in the demand of lithium in the last few decades. While mining resources of this element have been steadily exploited and are rapidly depleting, water resources constitute an interesting reservoir just out of reach of current technologies. Several techniques are being explored and novel materials engineered. While evaporation is very time-consuming and has large footprints, ion sieves and supramolecular systems can be suitably tailored and even integrated into membrane and electrochemical techniques. This review gives a comprehensive overview of the available solutions to recover lithium from water resources both by passive and electrically enhanced techniques. Accordingly, this work aims to provide in a single document a rational comparison of outstanding strategies to remove lithium from aqueous sources. To this end, practical figures of merit of both main groups of techniques are provided. An absence of a common experimental protocol and the resulting variability of data and experimental methods are identified. The need for a shared methodology and a common agreement to report performance metrics are underlined.

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Computational and NMR Studies on the Complexation of Lithium Ion to 8‐Crown‐4

et al. 2019

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Lithium ion selective crown ethers have been the subject of much research for a multitude of applications. Current research is aimed at structurally rigidifying crown ethers, as restructuring of the crown ether ring upon ion binding is energetically unfavorable. In this work, the lithium ion binding ability of the relatively rigid 8‐crown‐4 was investigated both computationally by density functional theory calculations and experimentally by 1H and 7Li NMR spectroscopy. Although both computational and experimental results showed 8‐crown‐4 to bind lithium ion, this binding was found to be weak compared to larger crown ethers. The computational analysis revealed that the complexation is driven by enthalpy rather than entropy, illustrating that rigidity is only of nominal importance. To elucidate the origin of the favorable interaction of lithium ion with crown ethers, activation strain analyses and energy decomposition analyses were performed pointing to the favorable interaction being mainly electrostatic in nature. 8‐crown‐4 presents the smallest crown ether reported to date capable of binding lithium ion, possessing two distinct conformations from which it is able to do so.

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Design of lithium selective crown ethers: Synthesis, extraction and theoretical binding studies

Cited by 96 publications

References 50 publications

Aqueous Synthesis of 14‐15‐Membered Crown Ethers with Mixed O, N and S Heteroatoms: Experimental and Theoretical Binding Studies with Platinum‐Group Metals

Aqueous Synthesis of 14‐15‐Membered Crown Ethers with Mixed O, N and S Heteroatoms: Experimental and Theoretical Binding Studies with Platinum‐Group Metals

Recent Advances in the Lithium Recovery from Water Resources: From Passive to Electrochemical Methods

Computational and NMR Studies on the Complexation of Lithium Ion to 8‐Crown‐4

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