Re-evaluation of the Acid Dissociation Constants of the Hydroxyl Groups in Tetrasodium 25,26,27,28-Tetrahydroxycalix[4]arene-5,11,17,23-tetrasulfonate

Yoshida, Isao; Yamamoto, Naohiro; Sagara, Fumio; Ishii, Daido; Ueno, K.; Shinkai, Seiji

doi:10.1246/bcsj.65.1012

Cited by 68 publications

(42 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3), was also in a form of tetrahydroxytetrasodiumsulfonate. 2 The results of the elemental analyses and IR spectra suggest the presence of water in 1 8 . The presence of water is also reported elsewhere.…”

Section: Resultsmentioning

confidence: 94%

“…Procedures, instrumentation and methods for pH (-log[H + ]) measurement similar to those described in our previous paper 2 were used for the pH titrations. The sample solution containing 0.05 -0.1 mmol of 1 8 was titrated with 0.1 M carbonate free potassium hydroxide in a 50 ml water jacket cell in the presence and absence of metal ion at 25˚C in a nitrogen stream.…”

Section: Ph Titrationmentioning

confidence: 99%

“…Since, almost all UO 2 2+ in seawater is present in the form of the bicarbonate complex, UO 2 (CO 3 ) 2 2-, due to the presence of carbonate ion, we studied the influence of carbonate ion on the formation of a 1 8 -UO 2 2+ complex.…”

Section: Effect Of Carbonate Ionmentioning

confidence: 99%

See 2 more Smart Citations

Another Uranophile Sodium Hydroxycalix[8]arene-p-sulfonate: Its Acid Dissociation and Divalent Metal Ion Binding Properties

Sonoda¹,

Hayashi²,

Nishida³

et al. 1998

ANAL. SCI.

Self Cite

View full text Add to dashboard Cite

The development of a peculiar ligand which can selectively extract UO 2 2+ from seawater has attracted extensive attention from chemists for more than two decades because of its importance in relation to energy problems. As a possible unique solution for this problem, Shinkai et al. 1 synthesized a macrocyclic ligand with a nearly coplanar arrangement of either five or six donating groups which can serve as a specific donating group for UO 2 2+ uptake. They examined the complexing ability of these groups with various divalent metal ions. They found that sodium hydroxycalix [5]arene-psulfonate, 1 5 , sodium hydroxycalix[6]arene-p-sulfonate, 1 6 , and their penta-or hexacarboxylated derivatives, 1 5 CH 2 COOH and 1 6 CH 2 COOH form 1:1 complexes with UO 2 2+ and that the complexes have remarkably large stability constants (log K UO2 =18.9 -19.2) with high selectivity factors (log(K UO2 /K M2+ )=10 -17) in water.1 Such high selectivity was attributed to the rigged skeleton of calix[n]arenes (n=5 and 6) which can provide pre-organized penta-or hexacoordination geometry for the binding of UO 2 2+ . We investigated divalent metal ion binding properties of sodium hydroxycalix [8]arene-p-sulfonate, 1 8 , which has eight donating groups on a more flexible macrocyclic skeleton than those of 1 5 and 1 6 . We found that 1 8 forms a highly stable 1:2 (1 8 :UO 2 2+ ) complex with UO 2 2+ , similar to that formed by 1 5 and 1 6 in stability. But extremely unstable 1:1 complexes were formed with other divalent metal ions such as Ca 2+ and Zn 2+ , according to accurate analyses of pH titration curves. There was no complex formed with Cu 2+ . In the present paper, we report acid dissociation constants of 1 8 , its complex formation reactions with some divalent metal ions including UO 2 2+ together with their stability constants, high selectivity factors for UO 2 2+ in divalent metal ions, and the finding that 1 8 is another uranophile which has highly selective reactivity for UO 2 2+ . Experimental

show abstract

Section: Resultsmentioning

confidence: 94%

Section: Ph Titrationmentioning

confidence: 99%

See 1 more Smart Citation

Another Uranophile Sodium Hydroxycalix[8]arene-p-sulfonate: Its Acid Dissociation and Divalent Metal Ion Binding Properties

Sonoda¹,

Hayashi²,

Nishida³

et al. 1998

ANAL. SCI.

Self Cite

View full text Add to dashboard Cite

show abstract

“…1 pSulfonatocalix[n]arene in which n moles of a sulfonic acid group are introduced to a p-position of each phenol group, is soluble in water, and increases the acidity of hydroxyl groups and the reactivity with metal ions in aqueous solution. 2,3 p-Nitrocalix [6]arene (CALX-N6, L), which has 6 moles of a nitro group to the p-position of each phenol group, as indicated in Fig. 1, increases the acidity of hydroxyl groups to pKa1 = 2.72, pKa2 = 5.71 and pKa3 = 11.6, 4 like p-sulfonatocalix [6]arene, CALX-S6 (pKa1 = 3.28, pKa2 = 4.86 and pKa3 = 11.5).…”

mentioning

confidence: 99%

“…2,3 p-Nitrocalix [6]arene (CALX-N6, L), which has 6 moles of a nitro group to the p-position of each phenol group, as indicated in Fig. 1, increases the acidity of hydroxyl groups to pKa1 = 2.72, pKa2 = 5.71 and pKa3 = 11.6, 4 like p-sulfonatocalix [6]arene, CALX-S6 (pKa1 = 3.28, pKa2 = 4.86 and pKa3 = 11.5).…”

mentioning

confidence: 99%

Complex Formation of p-Nitrocalix[6]arene with Rare Earth Metal Ions

et al. 2006

Self Cite

View full text Add to dashboard Cite

Calix [n]arene is a macrocyclic polyphenol in which n moles of phenol are combined with n moles of a methylene group, which is known as a new functional compound that can recognize molecules and ions by hydroxyl and/or by phenyl groups arranged on a molecular rim, or by a molecular cavity, making for a useful separation and analytical reagent. 1 pSulfonatocalix[n]arene in which n moles of a sulfonic acid group are introduced to a p-position of each phenol group, is soluble in water, and increases the acidity of hydroxyl groups and the reactivity with metal ions in aqueous solution. 2,3 p-Nitrocalix [6]arene (CALX-N6, L), which has 6 moles of a nitro group to the p-position of each phenol group, as indicated in Fig. 1, increases the acidity of hydroxyl groups to pKa1 = 2.72, pKa2 = 5.71 and pKa3 = 11.6, 4 like p-sulfonatocalix [6]arene, CALX-S6 (pKa1 = 3.28, pKa2 = 4.86 and pKa3 = 11.5). 5,6 Although these are the values in 4% (v/v) acetone aqueous solution, because CALX-N6 is insoluble in water, the acid dissociation behavior is very similar to that of CALX-S6. Therefore, it can also be estimated that the property of CALX-N6 as a ligand resembles that of CALX-S6. As reported in a previous paper, 4 CALX-N6 formed four kinds of protonated 1:1 uranyl complex species similar to CALX-S6. In the present study, the complex formation of CALX-N6 with a series of rare earth metal ions was investigated, and it was found that CALX-N6 reacts with rare earth metal ions to form a 1:1 complex, ML, with light rare earth metal ions (M 3+ ) and a 1:2 complex, ML2, with heavy M 3+ . Their conditional stability constants at about 25˚C were determined. ExperimentalReagents and solution CALX-N6 was prepared by the nitration of CALX-S6 with HNO3 according to a method reported by Shinkai et al.,7 and was confirmed to be CALX-N6 by elemental analysis, 1 H-NMR and IR. This was dissolved in acetone, and then diluted with water to make an acetone aqueous solution of the appropriate concentration.Chlorides or nitrates of rare earth metal ions (M 3+ ) were obtained from Wako Junyaku Kogyo Co., in analytical reagent grade. These were dissolved to make 0.01 mol dm -3 aqueous solutions, standardized by a titration method using a standard EDTA solution, then appropriately diluted and used to study the complex formation reaction with CALX-N6. Other reagents such as tartaric acid and EDTA, and solvents, such as acetone, were also obtained from Wako, and were of analytical reagent grade.The absorption spectra were measured using Shimadzu UV-2450 and UV-180 spectrophotometers with a 1 cm light pass length quartz cell. The solution pH was measured using a Horiba F-21 pH meter. Binding ratio of the metal complexInto a 25 or 50 cm 3 measuring flask, calculated amounts of CALX-N6, M 3+ and pH buffer solution (pH 10) were added and diluted to the mark with deionized water and left in a temperature-controlled room at about 25˚C. After standing for 48 h, the absorption spectrum of each sample solution was measured at 350 -600 nm. The absorbance at the absor...

show abstract

Fluorescence Regeneration as a Signaling Principle for Choline and Carnitine Binding: A Refined Supramolecular Sensor System Based on a Fluorescent Azoalkane

Bakirci

Nau

2005

Adv Funct Materials

127

View full text Add to dashboard Cite

The fluorescent azoalkane, 2,3‐diazabicyclo[2.2.2]oct‐2‐ene (DBO), forms inclusion complexes with p‐sulfonatocalix[4]arene (CX4). The binding constants are on the order of 103 M–1 in water. The addition of CX4 to DBO solutions results in an efficient fluorescence quenching (up to 90 %). This supramolecular system can be used as a truly water‐soluble sensor system to signal the binding of organic ammonium ions over a large pH range. Addition of choline and carnitine derivatives and tetraalkylammonium ions results in regeneration of this fluorescence, from which the binding constants (KC = 103–105 M–1) are calculated by means of a competitive complexation model. Electrostatic effects are observed, namely, a more‐than‐one order of magnitude weaker binding of the carnitines in neutral solution.

show abstract

Re-evaluation of the Acid Dissociation Constants of the Hydroxyl Groups in Tetrasodium 25,26,27,28-Tetrahydroxycalix[4]arene-5,11,17,23-tetrasulfonate

Cited by 68 publications

References 5 publications

Another Uranophile Sodium Hydroxycalix[8]arene-p-sulfonate: Its Acid Dissociation and Divalent Metal Ion Binding Properties

Another Uranophile Sodium Hydroxycalix[8]arene-p-sulfonate: Its Acid Dissociation and Divalent Metal Ion Binding Properties

Complex Formation of p-Nitrocalix[6]arene with Rare Earth Metal Ions

Fluorescence Regeneration as a Signaling Principle for Choline and Carnitine Binding: A Refined Supramolecular Sensor System Based on a Fluorescent Azoalkane

Contact Info

Product

Resources

About