Lithium cation enhances anion binding in a tripodal phosphine oxide-based ditopic receptor

Gavette, Jesse V.; Lara, Juven; Berryman, Orion B.; Zakharov, Lev N.; Haley, Michael M.; Johnson, Darren W.

doi:10.1039/c1cc12475g

Cited by 13 publications

(7 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Encouraged by the ion-pair binding properties of our previously synthesized receptor 1 , 32 we designed the related receptor 2 , starting from t -Boc-protected γ-aminobutyric acid following a literature procedure using di(tert-butyl) dicarbonate. 33 The resultant amine-protected amino acid was then combined with tris(aminomethyl)-phosphine oxide (produced in situ from the trishydrobromide salt) in a 3-fold HBTU-assisted amide coupling reaction in DMF.…”

Section: Resultsmentioning

confidence: 99%

“…32 b ΔΔG° metal = (ΔG° receptor·metal·halide complex ) − (ΔG° receptor·halide complex ). c K a < 15 M −1 and could not be accurately determined. d Calculated assuming ΔG° receptor· iodide complex = 15 M −1 . e Titrations had errors of ≤ 17%. …”

Section: Figmentioning

confidence: 99%

“…36 Association constants of previously reported receptor 1 are included for reference (Table 1). 32 Multiple titrations of 2 with the halides demonstrated that the strongest association occurs with chloride (580 M À1 ) followed by bromide (100 M À1 ), and the association with iodide was too small to be accurately determined, trending expectedly with the Hofmeister series. 37 Titrations of 2$Li + with the halides followed the same trend compared to the metal-free system, but gave 3-and 12-fold increases in association constants for chloride and bromide, respectively.…”

Section: H Nmr Binding Studiesmentioning

confidence: 99%

“…a Values were previously reported. 32 b DDG metal ¼ (DG receptor$metal$halide complex ) À (DG receptor$halide complex ). c K a < 15 M À1 and could not be accurately determined.…”

Section: H Nmr Binding Studiesmentioning

confidence: 99%

“…1) provides enhanced anion binding in the presence of lithium over sodium and the degree of enhancement is greatest for bromide. 32 To better understand this phenomenon, the new elongated receptor 2 (Fig. 1) was prepared in an effort to further elucidate the binding trends witnessed for 1 .…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Lithium-selective phosphine oxide-based ditopic receptors show enhanced halide binding upon alkali metal ion coordination

et al. 2013

Self Cite

View full text Add to dashboard Cite

Previous work on a ditopic receptor based on a tripodal phosphine oxide core demonstrated preferential enhancement of bromide binding over chloride or iodide in the presence of lithium cation. Current studies on an elongated receptor provide evidence that preferential bromide binding enhancement in the presence of lithium cation is common to this receptor class in general, and that lengthening of the receptor results in an overall increase in halide association. Furthermore, the extended receptor shows a strong preference for Li+ binding in solution.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Figmentioning

confidence: 99%

Section: H Nmr Binding Studiesmentioning

confidence: 99%

“…a Values were previously reported. 32 b DDG metal ¼ (DG receptor$metal$halide complex ) À (DG receptor$halide complex ). c K a < 15 M À1 and could not be accurately determined.…”

Section: H Nmr Binding Studiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Lithium-selective phosphine oxide-based ditopic receptors show enhanced halide binding upon alkali metal ion coordination

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

N‐Heterocyclic Olefin‐Phosphines Based Cationic Ruthenium Complexes as Pre‐Catalysts for Dual C−H Bond Functionalizations

Kumar Sahoo,

Das,

Jyoti Panda

et al. 2024

Adv Synth Catal

View full text Add to dashboard Cite

Two N‐heterocyclic olefin‐phosphines and the corresponding ruthenium complexes were synthesized and structurally characterized. One of the cationic complexes [(BzIM)(NHOP)Ru(p‐cymene)Cl2]I was employed as a catalyst in N‐benzylbenzamides/alkyne coupling reactions. With this catalytic protocol a variety of substituted isoquinolones were synthesized through ortho‐selective double C‐H bond functionalization involving oxidative annulation followed by olefination reactions. All these products were achieved in one‐pot manner without the use of additives.

show abstract

A Series of Amino Acid Functionalized Tripodal Hexaamide Anion Receptors: Ion‐Pair‐Assisted Capped‐Cleft Formation by a Pentafluorophenyl‐Functionalized Amide

Bose

Ravikumar

Akhuli

et al. 2012

Chemistry An Asian Journal

View full text Add to dashboard Cite

A new series of tris(2‐aminoethyl)amine (tren)‐based L‐alanine amino acid backboned tripodal hexaamide receptors (L1–L5) with various attached moieties based on electron‐withdrawing fluoro groups and lipophilicity have been synthesized and characterized. Detailed binding studies of L1–L5 with different anions, such as halides (F−, Cl−, Br−, and I−) and oxyanions (AcO−, BzO− (Bz=benzoyl), NO3−, H2PO4−, and HSO4−), have been carried out by isothermal titration calorimetric (ITC) experiments in acetonitrile/dimethylsulfoxide (99.5:0.5 v/v) at 298 K. ITC titration experiments have clearly shown that receptors L1–L4 invariably form 1:1 complexes with Cl−, AcO−, BzO−, and HSO4−, whereas L5 forms a 1:1 complex only with AcO−. In the case of Br−, I−, and NO3−, no appreciable heat change is observed owing to weak interactions between these anions and receptors; this is further confirmed by 1H NMR spectroscopy. The ITC binding studies of F− and H2PO4− do not fit well for a 1:1 binding model. Furthermore, ITC binding studies also revealed slightly higher selectivity of this series of receptors towards AcO− over Cl−, BzO−, and HSO4−. Solid‐state structural evidence for the recognition of Cl− by this new category of receptor was confirmed by single‐crystal X‐ray structural analysis of the complex of tetrabutylammonium chloride (TBACl) and L1. Single‐crystal X‐ray diffraction clearly showed that the pentafluorophenyl‐functionalized amide receptor (L1) encapsulated Cl− in its cavity by hydrogen bonds from amides, and the cavity of L1 was capped with a TBA cation through hydrogen bonding and ion‐pair interactions to form a capped‐cleft orientation. To understand the role of the cationic counterpart in solution‐state Cl− binding processes with this series of receptors (L1–L4), a detailed Cl− binding study was carried out with three different tetraalkylammonium (Me4N+, Et4N+, and Bu4N+) salts of Cl−. The binding affinities of these receptors with different tetralkylammonium salts of Cl− gave binding constants with the TBA cation in the following order: butyl>ethyl>methyl. This study further supports the role of the TBA countercation in ion‐pair recognition by this series of receptors.

show abstract

Lithium cation enhances anion binding in a tripodal phosphine oxide-based ditopic receptor

Cited by 13 publications

References 37 publications

Lithium-selective phosphine oxide-based ditopic receptors show enhanced halide binding upon alkali metal ion coordination

Lithium-selective phosphine oxide-based ditopic receptors show enhanced halide binding upon alkali metal ion coordination

N‐Heterocyclic Olefin‐Phosphines Based Cationic Ruthenium Complexes as Pre‐Catalysts for Dual C−H Bond Functionalizations

A Series of Amino Acid Functionalized Tripodal Hexaamide Anion Receptors: Ion‐Pair‐Assisted Capped‐Cleft Formation by a Pentafluorophenyl‐Functionalized Amide

Contact Info

Product

Resources

About