Shoichi Katsuta - Academia.edu (original) (raw)

Papers by Shoichi Katsuta

Research paper thumbnail of An Electrochemical Understanding of Extraction of Silver Picrate by Benzo-3<i>m</i>-Crown-<i>m</i> Ethers (<i>m</i> = 5, 6) into 1,2-Dichloroethane and Dichloromethane

American Journal of Analytical Chemistry, 2014

Research paper thumbnail of Solvent extraction of permanganates (Na, K) by 18-crown-6 ether from water into 1,2-dichloroethane: elucidation of an extraction equilibrium based on component equilibria

Talanta, 2003

Ion-pair formation constants (K(MLA) mol(-1) dm(3)) of Na(+)- and K(+)-18-crown-6 ether (18C6) co... more Ion-pair formation constants (K(MLA) mol(-1) dm(3)) of Na(+)- and K(+)-18-crown-6 ether (18C6) complexes with MnO(4)(-) in water (w) were determined potentiometrically at 25 degrees C. Simultaneously, extraction constants (K(ex) mol(-2) dm(6)) of the permanganates with 18C6 from w into 1,2-dichloroethane at 25 degrees C were obtained from the spectrophotometric determination of distribution ratios of the permanganates. These K(ex) values were divided into K(MLA) and other three component equilibrium constants and thereby extraction-selectivity and -ability were discussed in comparison with corresponding metal picrate-18C6 extraction systems reported before.

Research paper thumbnail of Mechanisms and Rules of Anion Partition into Ionic Liquids: Phenolate Ions in Ionic Liquid/Water Biphasic Systems

The Journal of Physical Chemistry B, 2012

It is important to understand the mechanisms and general rules of ion partitioning in hydrophobic... more It is important to understand the mechanisms and general rules of ion partitioning in hydrophobic ionic liquid (IL)/water biphasic systems in order to predict the extractability of an ionic species with various ILs. In this study, we have investigated the partition of picrate ion (target anion, T(-)) from aqueous sodium picrate solutions into several ILs and the accompanying changes in aqueous concentrations of the IL component cation (C(+)) and anion (A(-)) at 298.2 K. The main ILs examined are 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide, 1-butyl-3-methylimidazolium hexafluorophosphate, and 1-methyl-3-octylimidazolium bis(trifluoromethanesulfonyl)amide. The aqueous concentrations of C(+) and A(-) decreased and increased, respectively, with the extraction of T(-) into the IL phase. From the standpoint of equilibrium, the partition behavior of T(-) can be explained both by the anion exchange with A(-) in the IL phase and by the ion pair extraction with C(+) in the aqueous phase. The aqueous concentrations of C(+) and A(-) are governed by the solubility product of the IL (K(sp)). The distribution ratio of T(-) is expressed as a function of Δ[T(-)](W), namely, the difference between the initial and equilibrium concentrations of T(-) in the aqueous phase; the distribution ratio of T(-) is nearly constant when Δ[T(-)](W) &amp;amp;amp;amp;amp;amp;lt; K(sp)(1/2), but decreases with increasing Δ[T(-)](W) in the larger Δ[T(-)](W) region. The equilibrium constants of the ion pair extraction and the ion exchange extraction have been determined for picrate and other phenolate ions whose partition data were previously reported. The dependences of the extraction constants and extractability on the kinds of IL component ions can be quantitatively explained on the basis of the variations of K(sp).

Research paper thumbnail of Extraction of sodium and potassium perchlorates with benzo-18-crown-6 into various organic solvents. Quantitative elucidation of anion effects on the extraction-ability and -selectivity for Na+ and K+

Talanta, 2002

To investigate quantitatively the anion effect on the extraction-ability and -selectivity of benz... more To investigate quantitatively the anion effect on the extraction-ability and -selectivity of benzo-18-crown-6 (B18C6) for alkali metal ions, the constants for overall extraction into various diluents having low dielectric constants (K(ex)) and aqueous ion-pair formation (K(MLA)) of B18C6-sodium and potassium perchlorate 1:1:1 complexes (MLA) were determined at 25 degrees C. The K(ex) value was analyzed by the four fundamental equilibrium constants. The K(MLA) values were determined by applying our established method to this perchlorate extraction system. The K(M(B18C6)A) value of the perchlorate is much larger for K(+) than for Na(+), and is much smaller than that of the picrate. The K(M(B18C6)A) value makes a minor contribution to the magnitude of K(ex) for the perchlorate system, but a major contribution to that for the picrate one. The distribution behavior of the B18C6 1:1:1 complexes with the alkali metal perchlorates follows the regular solution theory. For the diluent with a high dipole moment, however, the 1:1:1 complexes somewhat undergo the dipole-dipole interaction. B18C6 always shows very high extraction selectivity for KClO(4) over NaClO(4), which is determined mostly by the much greater log/(log K(MLA)) value for K(+) than for Na(+). The extraction-ability and -selectivity of B18C6 for Na(+) and K(+) ions with a perchlorate ion were compared with those with a picrate ion in terms of the fundamental equilibrium constants. The K(+) extraction-selectivity of B18C6 over Na(+) for the perchlorate system is superior to that for the picrate one, which is caused largely by the greater log/(log K(K(B18C6)A))-log/(log K(Na(B18C6)A)) value for the perchlorate than for the picrate. The perchlorate system is recommended for extraction separation of K(+) from Na(+).

Research paper thumbnail of Solvent extraction of silver picrate by 3m-crown-m ethers (m = 5, 6) and its mono-benzo-derivative from water into benzene or chloroform: elucidation of an extraction equilibrium using component equilibrium constants

Research paper thumbnail of Extraction of sodium and potassium picrates with 16-crown-5 into various diluents. Elucidation of fundamental equilibria determining the extraction selectivity for Na+ over K+

Talanta, 1999

To quantitatively elucidate the effects of the side chains and diluents on the extraction selecti... more To quantitatively elucidate the effects of the side chains and diluents on the extraction selectivity for sodium and potassium picrates of 15-(2,5-dioxahexyl)-15-methyl-16-crown-5 (L16C5) from the viewpoint of equilibrium, the constants for the overall extraction (K(ex)), the partition for various diluents of low dielectric constants (K(D,MLA)), and the aqueous ion-pair formation (K(MLA)) of L16C5-sodium and -potassium picrate 1:1:1 complexes were determined at 25 degrees C; the distribution constants of L16C5 were also measured at 25 degrees C. The log K(MLA) values for Na(+) and K(+) are 2.74+/-0.29 and 1.70+/-0.36, respectively. In going from 16-crown-5 (16C5) to L16C5, the side chains decrease the K(MLA) value, but do not increase the difference in K(MLA) between Na(+) and K(+). The distribution behavior of L16C5 and its 1:1:1 complexes with the alkali metal picrates closely obeys regular solution theory, except for chloroform. Molar volumes and solubility parameters of L16C5 and the 1:1:1 complexes were determined. The magnitude of K(ex) is mainly governed by the K(M(L16C5)A) value. For every diluent, L16C5 shows Na(+) extraction selectivity over K(+). The Na(+) extraction selectivity of L16C5 is determined completely by K(M(L16C5)A). The extraction ability and selectivity for sodium and potassium picrates by L16C5 are compared with those of 16C5 on the basis of the fundamental equilibrium constants.

Research paper thumbnail of Solvent extraction of sodium perrhenate by 3m-crown-m ethers (m=5, 6) and their mono-benzo-derivatives into 1,2-dichloroethane: Elucidation of an overall extraction equilibrium based on component equilibria containing an ion-pair formation in water

Research paper thumbnail of Highly lithium-ion selective ionophores: macrocyclic trinuclear complexes of methoxy-substituted arene ruthenium bridged by 2,3-pyridinediolate

New Journal of Chemistry, 2013

Research paper thumbnail of Conductance Study of 1 : 1 19Crown6 Complexes with Various Mono and Bivalent Metal Ions in Water

Journal of Inclusion Phenomena and Macrocyclic Chemistry - J INCL PHENOM MACROCYCL CHEM, 1999

Formation constants (ML) of 1 : 1 19-crown-6 (19C6) complexes with mono- (M+) and bivalent metal ... more Formation constants (ML) of 1 : 1 19-crown-6 (19C6) complexes with mono- (M+) and bivalent metal ions (M2+) were determined in water at 25 °C by conductometry. The KML value of 19C6 for M+ and M2+ decreases in the order Rb+ = K+ > Tl+ > Na+ = Ag+ > Li+ ˜ Cs+ and Pb2+ > Ba2+ > Sr2+ > Cd2+ > Ca2+, respectively. The selectivity for the neighboring alkali metal ions in the periodic table is lower for 19C6 than for 18-crown-6 (18C6) except for the case of Rb+ and Cs+. The same is true for the alkaline earth metal ions. Generally, the KML values of 19C6 with M2+ are greater than those with M+. For Na+ and the ions which are smaller in size than Na+ (Li+, Ca2+, Cd2+), the KML value is larger for 19C6 than for 18C6, but the contrary holds for all the other ions of larger sizes than Na+. The limiting ionic molar conductivity (?°) of the 19C6–K+ complex in water at 25 °C was determined to be 43. Although 19C6 is larger than 18C6, the 19C6–K+ complex is much more mobile in...

Research paper thumbnail of Tetraalkylammonium Picrates in the Dichloromethane–Water System: Ion-Pair Formation and Liquid–Liquid Distribution of Free Ions and Ion Pairs

Journal of Solution Chemistry, 2007

Research paper thumbnail of Equilibrium Study on Ion-Pair Formation in Water and Distribution Between Water and m-Xylene of Tetraalkylammonium Picrates

Journal of Solution Chemistry, 2004

Research paper thumbnail of Extraction of lead picrate by 18-crown-6 ether into various diluents: Examples of sub-analysis of overall extraction equilibrium based on component equilibria

Journal of Molecular Liquids, 2014

Research paper thumbnail of Study on solute–solvent and solute–solute interactions for the dibenzo-24-crown-8-alkali metal picrate extraction system

Journal of Molecular Liquids, 2004

Abstract The constants of overall extraction equilibrium (Kex) and distribution (KD,MLA) for vari... more Abstract The constants of overall extraction equilibrium (Kex) and distribution (KD,MLA) for various diluents and aqueous ion-pair formation (KMLA) of dibenzo-24-crown-8 (DB24C8)–alkali metal (Na–Cs) picrate (MA) 1:1:1 complexes (M(DB24C8)A) were determined at 25 °C; the partition constants of DB24C8 were also measured at 25 °C. The distribution behavior of DB24C8 and M(DB24C8)A complexes can be explained by regular solution theory; the molar volumes and the solubility parameters of DB24C8 and M(DB24C8)A were determined. The log KD,MLA value for the same diluent decreases from Na to K and increases from K to Cs; however, the reverse is true of the log KMLA values. The extraction selectivity of DB24C8 for the alkali metal picrates decreases in the order Cs>Rb>K>Na or Cs>K≥or >Rb>Na. This is governed largely by the aqueous stability order for the M(DB24C8)+ complex ions. For every diluent, the plot of log Kex values against the reciprocal effective ionic radii of the alkali metals gives a straight line, which is related to Born's formula of solvation free energy. The reason for this was elucidated.

Research paper thumbnail of Ion-pair formation of cadmium-18-crown-6 ethers complex ions with picrate and chloride ions in water and distribution of its picrate ion-pair complex into benzene

Journal of Molecular Liquids, 2009

ABSTRACT

Research paper thumbnail of Thermodynamic study on transfer between polar solvents of 15-crown-5, benzo-15-crown-5, and their 1:1 complexes with alkali metal ions

Journal of Molecular Liquids, 2003

The thermodynamic parameters for transfer of 15-crown-5 (15C5) and benzo-15-crown-5 (B15C5) betwe... more The thermodynamic parameters for transfer of 15-crown-5 (15C5) and benzo-15-crown-5 (B15C5) between polar solvents (s) were precisely determined by solvent extraction. By using these data and the related literature values, the enthalpy (ΔH° t r ) and entropy changes (ΔS° t r ) of transfer of the 1:1 complexes of 15C5 and B15C5 with alkali metal ions (M + ) between the polar solvents were calculated from the Ph 4 As + /Ph 4 B - assumption via a thermodynamic cycle. Both the ΔH° t r and ΔS° t r values from water to s for 15C5 and B15C5 are all positive, reflecting hydrogen bonding between water and the ether oxygen atoms. The ΔH° t r (H 2 O→s) value is always greater for 15C5 than for B15C5. This is attributed to the stronger interaction with water of the aliphatic ether oxygen atom compared with the aromatic one. The enthalpic interaction with the solvents of the crown-5 complex is governed largely by that of the M + ion. The M(15C5) + and M(B15C5) + complexes act as hydrophobic structure-makers in water. Generally, the complexation in the solvent of 15C5 with Na + is enthalpically less favorable than that with K + {ΔH° N a ( 1 5 C 5 ) (s)> ΔH° K ( 1 5 C 5 ) (s)}. This is caused mostly by the much smaller ΔΗ° t r (Na + : gas→s) value compared with K + . However, the larger ΔH° t r (Na(15C5) + : gas→s) value compared with K + also contributes to the fact that ΔH° N a ( 1 5 C 5 ) (s)>ΔH° K ( 1 5 C 5 ) (s).

Research paper thumbnail of Stabilities in Polar Nonaqueous Solvents and Transfer Activity Coefficients from Water to Nonaqueous Solvents of 19Crown6Alkali Metal Ion Complexes

Journal of Inclusion Phenomena and Macrocyclic Chemistry - J INCL PHENOM MACROCYCL CHEM, 2000

Formation constants of 1 : 1 19-crown-6(19C6) complexes with alkali metal ions weredetermined con... more Formation constants of 1 : 1 19-crown-6(19C6) complexes with alkali metal ions weredetermined conductometrically at 25 °Cin acetonitrile(AN), propylene carbonate (PC), methanol, DMF, andDMSO. 19C6 always forms the most stable complex withK+. The selectivity order of 19C6 forheavy alkali metal ions isK+ > Rb+ > Cs+.The selectivity for Na+ varies withthe solvent; that for Li+ is the second lowest(AN, DMSO) or the lowest (PC). Transfer activity coefficients(S?H2 O) of19C6 from water to the nonaqueous solvents (S) weremeasured at 25 °C. The contributions of a methylenegroup and an ether oxygen atom to thelog S?H2 Ovalue of a crown ether wereobtained. The S?H2 Ovalues of the 19C6–alkali metal ion complexes(S?H2 O (ML+)) werecalculated, M+ and L denoting an alkali metal ionand a crown ether, respectively. For AN, PC, andCH3OH, although the M+ ion is more stronglysolvated by water than by AN, PC, or CH3OH, thelog S?H2 O (ML+) islarger than the correspondinglog S?H2 O (L)expect for th...

Research paper thumbnail of Stability of Ion Pairs of Bis(trifluoromethanesulfonyl)amide-Based Ionic Liquids in Dichloromethane

Journal of Chemical & Engineering Data, 2010

ABSTRACT

Research paper thumbnail of Ion-Pair Formation of 3m-Crown-m Ether (m = 5, 6) and Its Monobenzo Derivative Complex Ions with Several Pairing Anions in Water

Journal of Chemical & Engineering Data, 2006

Research paper thumbnail of Stability and Solvation of 1:1 Complexes of Dibenzo-21-crown-7 with Alkali Metal Ions in Polar Solvents

Journal of Chemical & Engineering Data, 2005

ABSTRACT Stability constants of 1:1 complexes of dibenzo-21-crown-7 (DB21C7) with alkali metal io... more ABSTRACT Stability constants of 1:1 complexes of dibenzo-21-crown-7 (DB21C7) with alkali metal ions have been determined at 25 °C in nitromethane, acetonitrile, propylene carbonate, and water by conductometry or capillary electrophoresis. The stability constants in acetonitrile, propylene carbonate, and water vary as Na+ K+ ≤ Rb+ &gt; Cs+; this selectivity pattern is the same as that previously reported in methanol. In these solvents, the K+/Na+ selectivity of DB21C7 is higher than that of dibenzo-18-crown-6 (DB18C6) and dibenzo-24-crown-8 (DB24C8). The stability constant in nitromethane, which has the weakest solvation power for the metal ions, decreases with increasing ionic size (Na+ &gt; K+ &gt; Rb+ &gt; Cs+), reflecting the gas-phase selectivity governed by the electrostatic interaction between the ether oxygen atoms and the metal ion. The transfer activity coefficients of DB21C7 and its alkali metal ion complexes from nitromethane to the other solvents have been determined to evaluate the solvation of these solutes. It is shown that DB21C7 shields the alkali metal ions effectively from the solvents; the shielding by DB21C7 is generally more effective than by DB18C6 but less effective than by DB24C8.

Research paper thumbnail of Stability and solvation of alkali metal ion complexes with dibenzo-30-crown-10

Inorganica Chimica Acta, 2005

Research paper thumbnail of An Electrochemical Understanding of Extraction of Silver Picrate by Benzo-3<i>m</i>-Crown-<i>m</i> Ethers (<i>m</i> = 5, 6) into 1,2-Dichloroethane and Dichloromethane

American Journal of Analytical Chemistry, 2014

Research paper thumbnail of Solvent extraction of permanganates (Na, K) by 18-crown-6 ether from water into 1,2-dichloroethane: elucidation of an extraction equilibrium based on component equilibria

Talanta, 2003

Ion-pair formation constants (K(MLA) mol(-1) dm(3)) of Na(+)- and K(+)-18-crown-6 ether (18C6) co... more Ion-pair formation constants (K(MLA) mol(-1) dm(3)) of Na(+)- and K(+)-18-crown-6 ether (18C6) complexes with MnO(4)(-) in water (w) were determined potentiometrically at 25 degrees C. Simultaneously, extraction constants (K(ex) mol(-2) dm(6)) of the permanganates with 18C6 from w into 1,2-dichloroethane at 25 degrees C were obtained from the spectrophotometric determination of distribution ratios of the permanganates. These K(ex) values were divided into K(MLA) and other three component equilibrium constants and thereby extraction-selectivity and -ability were discussed in comparison with corresponding metal picrate-18C6 extraction systems reported before.

Research paper thumbnail of Mechanisms and Rules of Anion Partition into Ionic Liquids: Phenolate Ions in Ionic Liquid/Water Biphasic Systems

The Journal of Physical Chemistry B, 2012

It is important to understand the mechanisms and general rules of ion partitioning in hydrophobic... more It is important to understand the mechanisms and general rules of ion partitioning in hydrophobic ionic liquid (IL)/water biphasic systems in order to predict the extractability of an ionic species with various ILs. In this study, we have investigated the partition of picrate ion (target anion, T(-)) from aqueous sodium picrate solutions into several ILs and the accompanying changes in aqueous concentrations of the IL component cation (C(+)) and anion (A(-)) at 298.2 K. The main ILs examined are 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide, 1-butyl-3-methylimidazolium hexafluorophosphate, and 1-methyl-3-octylimidazolium bis(trifluoromethanesulfonyl)amide. The aqueous concentrations of C(+) and A(-) decreased and increased, respectively, with the extraction of T(-) into the IL phase. From the standpoint of equilibrium, the partition behavior of T(-) can be explained both by the anion exchange with A(-) in the IL phase and by the ion pair extraction with C(+) in the aqueous phase. The aqueous concentrations of C(+) and A(-) are governed by the solubility product of the IL (K(sp)). The distribution ratio of T(-) is expressed as a function of Δ[T(-)](W), namely, the difference between the initial and equilibrium concentrations of T(-) in the aqueous phase; the distribution ratio of T(-) is nearly constant when Δ[T(-)](W) &amp;amp;amp;amp;amp;amp;lt; K(sp)(1/2), but decreases with increasing Δ[T(-)](W) in the larger Δ[T(-)](W) region. The equilibrium constants of the ion pair extraction and the ion exchange extraction have been determined for picrate and other phenolate ions whose partition data were previously reported. The dependences of the extraction constants and extractability on the kinds of IL component ions can be quantitatively explained on the basis of the variations of K(sp).

Research paper thumbnail of Extraction of sodium and potassium perchlorates with benzo-18-crown-6 into various organic solvents. Quantitative elucidation of anion effects on the extraction-ability and -selectivity for Na+ and K+

Talanta, 2002

To investigate quantitatively the anion effect on the extraction-ability and -selectivity of benz... more To investigate quantitatively the anion effect on the extraction-ability and -selectivity of benzo-18-crown-6 (B18C6) for alkali metal ions, the constants for overall extraction into various diluents having low dielectric constants (K(ex)) and aqueous ion-pair formation (K(MLA)) of B18C6-sodium and potassium perchlorate 1:1:1 complexes (MLA) were determined at 25 degrees C. The K(ex) value was analyzed by the four fundamental equilibrium constants. The K(MLA) values were determined by applying our established method to this perchlorate extraction system. The K(M(B18C6)A) value of the perchlorate is much larger for K(+) than for Na(+), and is much smaller than that of the picrate. The K(M(B18C6)A) value makes a minor contribution to the magnitude of K(ex) for the perchlorate system, but a major contribution to that for the picrate one. The distribution behavior of the B18C6 1:1:1 complexes with the alkali metal perchlorates follows the regular solution theory. For the diluent with a high dipole moment, however, the 1:1:1 complexes somewhat undergo the dipole-dipole interaction. B18C6 always shows very high extraction selectivity for KClO(4) over NaClO(4), which is determined mostly by the much greater log/(log K(MLA)) value for K(+) than for Na(+). The extraction-ability and -selectivity of B18C6 for Na(+) and K(+) ions with a perchlorate ion were compared with those with a picrate ion in terms of the fundamental equilibrium constants. The K(+) extraction-selectivity of B18C6 over Na(+) for the perchlorate system is superior to that for the picrate one, which is caused largely by the greater log/(log K(K(B18C6)A))-log/(log K(Na(B18C6)A)) value for the perchlorate than for the picrate. The perchlorate system is recommended for extraction separation of K(+) from Na(+).

Research paper thumbnail of Solvent extraction of silver picrate by 3m-crown-m ethers (m = 5, 6) and its mono-benzo-derivative from water into benzene or chloroform: elucidation of an extraction equilibrium using component equilibrium constants

Research paper thumbnail of Extraction of sodium and potassium picrates with 16-crown-5 into various diluents. Elucidation of fundamental equilibria determining the extraction selectivity for Na+ over K+

Talanta, 1999

To quantitatively elucidate the effects of the side chains and diluents on the extraction selecti... more To quantitatively elucidate the effects of the side chains and diluents on the extraction selectivity for sodium and potassium picrates of 15-(2,5-dioxahexyl)-15-methyl-16-crown-5 (L16C5) from the viewpoint of equilibrium, the constants for the overall extraction (K(ex)), the partition for various diluents of low dielectric constants (K(D,MLA)), and the aqueous ion-pair formation (K(MLA)) of L16C5-sodium and -potassium picrate 1:1:1 complexes were determined at 25 degrees C; the distribution constants of L16C5 were also measured at 25 degrees C. The log K(MLA) values for Na(+) and K(+) are 2.74+/-0.29 and 1.70+/-0.36, respectively. In going from 16-crown-5 (16C5) to L16C5, the side chains decrease the K(MLA) value, but do not increase the difference in K(MLA) between Na(+) and K(+). The distribution behavior of L16C5 and its 1:1:1 complexes with the alkali metal picrates closely obeys regular solution theory, except for chloroform. Molar volumes and solubility parameters of L16C5 and the 1:1:1 complexes were determined. The magnitude of K(ex) is mainly governed by the K(M(L16C5)A) value. For every diluent, L16C5 shows Na(+) extraction selectivity over K(+). The Na(+) extraction selectivity of L16C5 is determined completely by K(M(L16C5)A). The extraction ability and selectivity for sodium and potassium picrates by L16C5 are compared with those of 16C5 on the basis of the fundamental equilibrium constants.

Research paper thumbnail of Solvent extraction of sodium perrhenate by 3m-crown-m ethers (m=5, 6) and their mono-benzo-derivatives into 1,2-dichloroethane: Elucidation of an overall extraction equilibrium based on component equilibria containing an ion-pair formation in water

Research paper thumbnail of Highly lithium-ion selective ionophores: macrocyclic trinuclear complexes of methoxy-substituted arene ruthenium bridged by 2,3-pyridinediolate

New Journal of Chemistry, 2013

Research paper thumbnail of Conductance Study of 1 : 1 19Crown6 Complexes with Various Mono and Bivalent Metal Ions in Water

Journal of Inclusion Phenomena and Macrocyclic Chemistry - J INCL PHENOM MACROCYCL CHEM, 1999

Formation constants (ML) of 1 : 1 19-crown-6 (19C6) complexes with mono- (M+) and bivalent metal ... more Formation constants (ML) of 1 : 1 19-crown-6 (19C6) complexes with mono- (M+) and bivalent metal ions (M2+) were determined in water at 25 °C by conductometry. The KML value of 19C6 for M+ and M2+ decreases in the order Rb+ = K+ > Tl+ > Na+ = Ag+ > Li+ ˜ Cs+ and Pb2+ > Ba2+ > Sr2+ > Cd2+ > Ca2+, respectively. The selectivity for the neighboring alkali metal ions in the periodic table is lower for 19C6 than for 18-crown-6 (18C6) except for the case of Rb+ and Cs+. The same is true for the alkaline earth metal ions. Generally, the KML values of 19C6 with M2+ are greater than those with M+. For Na+ and the ions which are smaller in size than Na+ (Li+, Ca2+, Cd2+), the KML value is larger for 19C6 than for 18C6, but the contrary holds for all the other ions of larger sizes than Na+. The limiting ionic molar conductivity (?°) of the 19C6–K+ complex in water at 25 °C was determined to be 43. Although 19C6 is larger than 18C6, the 19C6–K+ complex is much more mobile in...

Research paper thumbnail of Tetraalkylammonium Picrates in the Dichloromethane–Water System: Ion-Pair Formation and Liquid–Liquid Distribution of Free Ions and Ion Pairs

Journal of Solution Chemistry, 2007

Research paper thumbnail of Equilibrium Study on Ion-Pair Formation in Water and Distribution Between Water and m-Xylene of Tetraalkylammonium Picrates

Journal of Solution Chemistry, 2004

Research paper thumbnail of Extraction of lead picrate by 18-crown-6 ether into various diluents: Examples of sub-analysis of overall extraction equilibrium based on component equilibria

Journal of Molecular Liquids, 2014

Research paper thumbnail of Study on solute–solvent and solute–solute interactions for the dibenzo-24-crown-8-alkali metal picrate extraction system

Journal of Molecular Liquids, 2004

Abstract The constants of overall extraction equilibrium (Kex) and distribution (KD,MLA) for vari... more Abstract The constants of overall extraction equilibrium (Kex) and distribution (KD,MLA) for various diluents and aqueous ion-pair formation (KMLA) of dibenzo-24-crown-8 (DB24C8)–alkali metal (Na–Cs) picrate (MA) 1:1:1 complexes (M(DB24C8)A) were determined at 25 °C; the partition constants of DB24C8 were also measured at 25 °C. The distribution behavior of DB24C8 and M(DB24C8)A complexes can be explained by regular solution theory; the molar volumes and the solubility parameters of DB24C8 and M(DB24C8)A were determined. The log KD,MLA value for the same diluent decreases from Na to K and increases from K to Cs; however, the reverse is true of the log KMLA values. The extraction selectivity of DB24C8 for the alkali metal picrates decreases in the order Cs>Rb>K>Na or Cs>K≥or >Rb>Na. This is governed largely by the aqueous stability order for the M(DB24C8)+ complex ions. For every diluent, the plot of log Kex values against the reciprocal effective ionic radii of the alkali metals gives a straight line, which is related to Born's formula of solvation free energy. The reason for this was elucidated.

Research paper thumbnail of Ion-pair formation of cadmium-18-crown-6 ethers complex ions with picrate and chloride ions in water and distribution of its picrate ion-pair complex into benzene

Journal of Molecular Liquids, 2009

ABSTRACT

Research paper thumbnail of Thermodynamic study on transfer between polar solvents of 15-crown-5, benzo-15-crown-5, and their 1:1 complexes with alkali metal ions

Journal of Molecular Liquids, 2003

The thermodynamic parameters for transfer of 15-crown-5 (15C5) and benzo-15-crown-5 (B15C5) betwe... more The thermodynamic parameters for transfer of 15-crown-5 (15C5) and benzo-15-crown-5 (B15C5) between polar solvents (s) were precisely determined by solvent extraction. By using these data and the related literature values, the enthalpy (ΔH° t r ) and entropy changes (ΔS° t r ) of transfer of the 1:1 complexes of 15C5 and B15C5 with alkali metal ions (M + ) between the polar solvents were calculated from the Ph 4 As + /Ph 4 B - assumption via a thermodynamic cycle. Both the ΔH° t r and ΔS° t r values from water to s for 15C5 and B15C5 are all positive, reflecting hydrogen bonding between water and the ether oxygen atoms. The ΔH° t r (H 2 O→s) value is always greater for 15C5 than for B15C5. This is attributed to the stronger interaction with water of the aliphatic ether oxygen atom compared with the aromatic one. The enthalpic interaction with the solvents of the crown-5 complex is governed largely by that of the M + ion. The M(15C5) + and M(B15C5) + complexes act as hydrophobic structure-makers in water. Generally, the complexation in the solvent of 15C5 with Na + is enthalpically less favorable than that with K + {ΔH° N a ( 1 5 C 5 ) (s)> ΔH° K ( 1 5 C 5 ) (s)}. This is caused mostly by the much smaller ΔΗ° t r (Na + : gas→s) value compared with K + . However, the larger ΔH° t r (Na(15C5) + : gas→s) value compared with K + also contributes to the fact that ΔH° N a ( 1 5 C 5 ) (s)>ΔH° K ( 1 5 C 5 ) (s).

Research paper thumbnail of Stabilities in Polar Nonaqueous Solvents and Transfer Activity Coefficients from Water to Nonaqueous Solvents of 19Crown6Alkali Metal Ion Complexes

Journal of Inclusion Phenomena and Macrocyclic Chemistry - J INCL PHENOM MACROCYCL CHEM, 2000

Formation constants of 1 : 1 19-crown-6(19C6) complexes with alkali metal ions weredetermined con... more Formation constants of 1 : 1 19-crown-6(19C6) complexes with alkali metal ions weredetermined conductometrically at 25 °Cin acetonitrile(AN), propylene carbonate (PC), methanol, DMF, andDMSO. 19C6 always forms the most stable complex withK+. The selectivity order of 19C6 forheavy alkali metal ions isK+ > Rb+ > Cs+.The selectivity for Na+ varies withthe solvent; that for Li+ is the second lowest(AN, DMSO) or the lowest (PC). Transfer activity coefficients(S?H2 O) of19C6 from water to the nonaqueous solvents (S) weremeasured at 25 °C. The contributions of a methylenegroup and an ether oxygen atom to thelog S?H2 Ovalue of a crown ether wereobtained. The S?H2 Ovalues of the 19C6–alkali metal ion complexes(S?H2 O (ML+)) werecalculated, M+ and L denoting an alkali metal ionand a crown ether, respectively. For AN, PC, andCH3OH, although the M+ ion is more stronglysolvated by water than by AN, PC, or CH3OH, thelog S?H2 O (ML+) islarger than the correspondinglog S?H2 O (L)expect for th...

Research paper thumbnail of Stability of Ion Pairs of Bis(trifluoromethanesulfonyl)amide-Based Ionic Liquids in Dichloromethane

Journal of Chemical & Engineering Data, 2010

ABSTRACT

Research paper thumbnail of Ion-Pair Formation of 3m-Crown-m Ether (m = 5, 6) and Its Monobenzo Derivative Complex Ions with Several Pairing Anions in Water

Journal of Chemical & Engineering Data, 2006

Research paper thumbnail of Stability and Solvation of 1:1 Complexes of Dibenzo-21-crown-7 with Alkali Metal Ions in Polar Solvents

Journal of Chemical & Engineering Data, 2005

ABSTRACT Stability constants of 1:1 complexes of dibenzo-21-crown-7 (DB21C7) with alkali metal io... more ABSTRACT Stability constants of 1:1 complexes of dibenzo-21-crown-7 (DB21C7) with alkali metal ions have been determined at 25 °C in nitromethane, acetonitrile, propylene carbonate, and water by conductometry or capillary electrophoresis. The stability constants in acetonitrile, propylene carbonate, and water vary as Na+ K+ ≤ Rb+ &gt; Cs+; this selectivity pattern is the same as that previously reported in methanol. In these solvents, the K+/Na+ selectivity of DB21C7 is higher than that of dibenzo-18-crown-6 (DB18C6) and dibenzo-24-crown-8 (DB24C8). The stability constant in nitromethane, which has the weakest solvation power for the metal ions, decreases with increasing ionic size (Na+ &gt; K+ &gt; Rb+ &gt; Cs+), reflecting the gas-phase selectivity governed by the electrostatic interaction between the ether oxygen atoms and the metal ion. The transfer activity coefficients of DB21C7 and its alkali metal ion complexes from nitromethane to the other solvents have been determined to evaluate the solvation of these solutes. It is shown that DB21C7 shields the alkali metal ions effectively from the solvents; the shielding by DB21C7 is generally more effective than by DB18C6 but less effective than by DB24C8.

Research paper thumbnail of Stability and solvation of alkali metal ion complexes with dibenzo-30-crown-10

Inorganica Chimica Acta, 2005