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Yasuyuki Takeda - One of the best experts on this subject based on the ideXlab platform.

  • Selective Extraction of Lithium with a Macrocyclic Trinuclear Complex of (1,3,5-Trimethylbenzene)ruthenium(II) Bridged by 2,3-Dioxopyridine
    Analytical sciences : the international journal of the Japan Society for Analytical Chemistry, 2008
    Co-Authors: Shoichi Katsuta, Takahiro Imoto, Yoshihiro Kudo, Yasuyuki Takeda
    Abstract:

    A macrocyclic trinuclear complex of (1,3,5-trimethylbenzene)ruthenium(II) bridged by 2,3-dioxopyridine was synthesized, and the extraction properties for lithium and sodium Picrates were investigated in a dichloromethane/water system at 25 degrees C. The complex was found to have extremely high extractability and selectivity for lithium picrate; the logarithmic values of the extraction constants are 5.86 and 2.63 for Li(+) and Na(+), respectively. By using this complex as an extractant, nearly quantitative extraction and separation of Li(+) from Na(+) could be achieved by a single extraction.

  • extraction properties for alkali metal Picrates of macrocyclic trinuclear p cymene ruthenium ii and pentamethylcyclopentadienyl rhodium iii complexes
    Inorganica Chimica Acta, 2008
    Co-Authors: Shoichi Katsuta, Yoshihiro Kudo, Yudai Iwabe, Yayoi Kato, Yasuyuki Takeda
    Abstract:

    Abstract The solvent extraction properties of macrocyclic trinuclear organometallic complexes, [(p-cymene)Ru(pyO2)]3 and [Cp∗Rh(pyO2)]3 ( pyO 2 2 - = 2 , 3 -dioxopyridine, Cp ∗ = pentamethylcyclopentadienyl ) , for Li+, Na+, and K+ Picrates have been investigated in a dichloromethane–water system at 25 °C. The extraction rates of the alkali metal Picrates with these macrocyclic complex ligands are unusually slow; the shaking times required to attain equilibrium are at least 1 h for [(p-cymene)Ru(pyO2)]3 and 20–40 h for [Cp∗Rh(pyO2)]3. From analysis of the equilibrium data, the extraction constants (Kex = [ML+A−]o/[M+][L]o[A−]; M+ = alkali metal ion, L = macrocyclic ligand, A− = picrate ion, o = organic phase) have been determined. The log Kex value varies in the sequences, Li+ (5.72) > Na+ (4.50) > K+ (2.88) for [(p-cymene)Ru(pyO2)]3 and Li+ (4.79) > Na+ (2.70) ≈ K+ (2.69) for [Cp∗Rh(pyO2)]3. The Kex values of 6,6-dibenzyl-14-crown-4 (DBz14C4), which is one of the best Li+-selective crown ethers, have also been determined for comparison. It is revealed that [Cp∗Rh(pyO2)]3 is much superior to DBz14C4 both in the extractability for Li+ and the selectivity for Li+ over Na+.

  • Ion Pair Formation of 1-Alkyl-3-methylimidazolium Salts in Water
    Journal of Chemical & Engineering Data, 2007
    Co-Authors: Shoichi Katsuta, Ryuji Ogawa, Naoko Yamaguchi, Takuya Ishitani, Yasuyuki Takeda
    Abstract:

    Ion pair formation in water of a series of 1-alkyl-3-methylimidazolium cations (1-butyl-, C4mim+; 1-hexyl-, C6mim+; 1-octyl-, C8mim+) with BF4-, PF6-, bis(trifluoromethylsulfonyl)imide (Tf2N-), and picrate (Pic-) anions has been investigated by capillary electrophoresis at 25 °C. The formation constants at infinite dilution (KIP°) of the 1:1 ion pairs have been determined. For all the anions, the KIP° value increases with increasing alkyl chain length of the cation (i.e., C4mim+ < C6mim+ < C8mim+). Except for Pic-, the anion dependence of the KIP° value is always BF4- < PF6- < Tf2N-. The Pic- anion has a larger KIP° value with C8mim+ than the other anions, whereas the KIP° value of Pic− is smaller than or nearly equal to that of Tf2N− when the cation is C4mim+ or C6mim+; the KIP° value for Pic- varies most sensitively with the alkyl chain length of the cation. The KIP° values of the picrate salts are compared with those of tetraalkylammonium Picrates previously reported.

  • Equilibrium Study on Ion-Pair Formation in Water and Distribution Between Water and m-Xylene of Tetraalkylammonium Picrates
    Journal of Solution Chemistry, 2004
    Co-Authors: Shoichi Katsuta, Takuya Ishitani, Yoshihiro Kudo, Mika Suzuki, Yuki Ishii, Yasuyuki Takeda
    Abstract:

    The 1:1 ion-pair formation constants ( K _IP) of tetraalkylammonium (Me_4N^+, Et_4N^+, Pr_4N^+, Bu_4N^+, and Bu_3MeN^+) Picrates in water were determined by capillary electrophoresis at 25°C. The ion-pair extraction constants ( K _ex,ip) of the Picrates from water to m -xylene were determined by a batch-extraction method at 25°C, and the distribution constants ( K _D) of the neutral ion-pairs were calculated from the relationship K _D = K_ex,ip/ K _IP. The tetraalkylammonium ion having more methylene groups generally forms a slightly more stable ion-pair with the picrate ion in water, which is attributed to the lower hydration of the cation. For Me_4N^+, Et_4N^+, Pr_4N^+, and Bu_4N^+, the distribution of the ion pair into m -xylene increases in that order, and a linear relationship was found between log K _D and the number of methylene groups in the cation. This is consistently explained by the regular solution theory. It was also revealed that the ion pairs have a strong specific interaction with water. The ion pair of Bu_3MeN^+ has a higher distribution constant than that expected from the relationship between log K _D and the number of methylene groups for the symmetrical tetraalkylammonium ions. The cation dependence of the ion pair extractability is mostly governed by that of the distribution of the ion pair.

  • extraction of alkali metal li na k Picrates with benzo 15 crown 5 into various organic solvents elucidation of fundamental equilibria determining the extraction ability and selectivity
    Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2002
    Co-Authors: Yasuyuki Takeda, Kunio Hashimoto, Daisuke Yoshiyama, Shoichi Katsuta
    Abstract:

    To quantitatively elucidate the effects of the benzo group on the extraction-selectively and -ability of benzo-15-crown-5 (B15C5)for alkali metal ions, the constants of the overall extraction (Kex), thedistribution for various diluents having low dielectric constants (KD,MLA), and the aqueousion-pair formation (KMLA) of B15C5-alkali metal (Li, Na, K) picrate 1:1:1 complexes (MLA) weredetermined at 25 °C. The partition constants of B15C5were also measured at 25 °C. The log KMLA values for Li+, Na+, and K+ are -0.32 ± 0.22, 2.66 ± 0.19, and 0.71 ± 0.47, respectively. In going from 15-crown-5 (15C5) to B15C5, the benzo group considerably decreasesthe KMLA value for the same alkali metal ion. The distributionbehavior of B15C5 and its 1:1:1 complexes with the alkali metal Picrates closely obeys regularsolution theory, omitting chloroform. Molar volumes and solubility parameters of B15C5and the 1:1:1 complexes were determined. For every diluent, the Kex valuefor B15C5 increases in the order Li+ < K+ < Na+. KD,MLA makes anunfavorable contribution to the Na+ extraction-selectivity of B15C5 because of the smallest molar volume of the Na(B15C5)A complex. The Na+ extraction-selectivity of B15C5 is determined completely by much the highest KNa(B15C5)A value.The extraction-ability and -selectivity of B15C5 for the alkali metal Picrates are compared with those of 15C5on the basis of the underlying equilibrium constants.

Shoichi Katsuta - One of the best experts on this subject based on the ideXlab platform.

  • Selective Extraction of Lithium with a Macrocyclic Trinuclear Complex of (1,3,5-Trimethylbenzene)ruthenium(II) Bridged by 2,3-Dioxopyridine
    Analytical sciences : the international journal of the Japan Society for Analytical Chemistry, 2008
    Co-Authors: Shoichi Katsuta, Takahiro Imoto, Yoshihiro Kudo, Yasuyuki Takeda
    Abstract:

    A macrocyclic trinuclear complex of (1,3,5-trimethylbenzene)ruthenium(II) bridged by 2,3-dioxopyridine was synthesized, and the extraction properties for lithium and sodium Picrates were investigated in a dichloromethane/water system at 25 degrees C. The complex was found to have extremely high extractability and selectivity for lithium picrate; the logarithmic values of the extraction constants are 5.86 and 2.63 for Li(+) and Na(+), respectively. By using this complex as an extractant, nearly quantitative extraction and separation of Li(+) from Na(+) could be achieved by a single extraction.

  • extraction properties for alkali metal Picrates of macrocyclic trinuclear p cymene ruthenium ii and pentamethylcyclopentadienyl rhodium iii complexes
    Inorganica Chimica Acta, 2008
    Co-Authors: Shoichi Katsuta, Yoshihiro Kudo, Yudai Iwabe, Yayoi Kato, Yasuyuki Takeda
    Abstract:

    Abstract The solvent extraction properties of macrocyclic trinuclear organometallic complexes, [(p-cymene)Ru(pyO2)]3 and [Cp∗Rh(pyO2)]3 ( pyO 2 2 - = 2 , 3 -dioxopyridine, Cp ∗ = pentamethylcyclopentadienyl ) , for Li+, Na+, and K+ Picrates have been investigated in a dichloromethane–water system at 25 °C. The extraction rates of the alkali metal Picrates with these macrocyclic complex ligands are unusually slow; the shaking times required to attain equilibrium are at least 1 h for [(p-cymene)Ru(pyO2)]3 and 20–40 h for [Cp∗Rh(pyO2)]3. From analysis of the equilibrium data, the extraction constants (Kex = [ML+A−]o/[M+][L]o[A−]; M+ = alkali metal ion, L = macrocyclic ligand, A− = picrate ion, o = organic phase) have been determined. The log Kex value varies in the sequences, Li+ (5.72) > Na+ (4.50) > K+ (2.88) for [(p-cymene)Ru(pyO2)]3 and Li+ (4.79) > Na+ (2.70) ≈ K+ (2.69) for [Cp∗Rh(pyO2)]3. The Kex values of 6,6-dibenzyl-14-crown-4 (DBz14C4), which is one of the best Li+-selective crown ethers, have also been determined for comparison. It is revealed that [Cp∗Rh(pyO2)]3 is much superior to DBz14C4 both in the extractability for Li+ and the selectivity for Li+ over Na+.

  • Ion Pair Formation of 1-Alkyl-3-methylimidazolium Salts in Water
    Journal of Chemical & Engineering Data, 2007
    Co-Authors: Shoichi Katsuta, Ryuji Ogawa, Naoko Yamaguchi, Takuya Ishitani, Yasuyuki Takeda
    Abstract:

    Ion pair formation in water of a series of 1-alkyl-3-methylimidazolium cations (1-butyl-, C4mim+; 1-hexyl-, C6mim+; 1-octyl-, C8mim+) with BF4-, PF6-, bis(trifluoromethylsulfonyl)imide (Tf2N-), and picrate (Pic-) anions has been investigated by capillary electrophoresis at 25 °C. The formation constants at infinite dilution (KIP°) of the 1:1 ion pairs have been determined. For all the anions, the KIP° value increases with increasing alkyl chain length of the cation (i.e., C4mim+ < C6mim+ < C8mim+). Except for Pic-, the anion dependence of the KIP° value is always BF4- < PF6- < Tf2N-. The Pic- anion has a larger KIP° value with C8mim+ than the other anions, whereas the KIP° value of Pic− is smaller than or nearly equal to that of Tf2N− when the cation is C4mim+ or C6mim+; the KIP° value for Pic- varies most sensitively with the alkyl chain length of the cation. The KIP° values of the picrate salts are compared with those of tetraalkylammonium Picrates previously reported.

  • Equilibrium Study on Ion-Pair Formation in Water and Distribution Between Water and m-Xylene of Tetraalkylammonium Picrates
    Journal of Solution Chemistry, 2004
    Co-Authors: Shoichi Katsuta, Takuya Ishitani, Yoshihiro Kudo, Mika Suzuki, Yuki Ishii, Yasuyuki Takeda
    Abstract:

    The 1:1 ion-pair formation constants ( K _IP) of tetraalkylammonium (Me_4N^+, Et_4N^+, Pr_4N^+, Bu_4N^+, and Bu_3MeN^+) Picrates in water were determined by capillary electrophoresis at 25°C. The ion-pair extraction constants ( K _ex,ip) of the Picrates from water to m -xylene were determined by a batch-extraction method at 25°C, and the distribution constants ( K _D) of the neutral ion-pairs were calculated from the relationship K _D = K_ex,ip/ K _IP. The tetraalkylammonium ion having more methylene groups generally forms a slightly more stable ion-pair with the picrate ion in water, which is attributed to the lower hydration of the cation. For Me_4N^+, Et_4N^+, Pr_4N^+, and Bu_4N^+, the distribution of the ion pair into m -xylene increases in that order, and a linear relationship was found between log K _D and the number of methylene groups in the cation. This is consistently explained by the regular solution theory. It was also revealed that the ion pairs have a strong specific interaction with water. The ion pair of Bu_3MeN^+ has a higher distribution constant than that expected from the relationship between log K _D and the number of methylene groups for the symmetrical tetraalkylammonium ions. The cation dependence of the ion pair extractability is mostly governed by that of the distribution of the ion pair.

  • extraction of alkali metal li na k Picrates with benzo 15 crown 5 into various organic solvents elucidation of fundamental equilibria determining the extraction ability and selectivity
    Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2002
    Co-Authors: Yasuyuki Takeda, Kunio Hashimoto, Daisuke Yoshiyama, Shoichi Katsuta
    Abstract:

    To quantitatively elucidate the effects of the benzo group on the extraction-selectively and -ability of benzo-15-crown-5 (B15C5)for alkali metal ions, the constants of the overall extraction (Kex), thedistribution for various diluents having low dielectric constants (KD,MLA), and the aqueousion-pair formation (KMLA) of B15C5-alkali metal (Li, Na, K) picrate 1:1:1 complexes (MLA) weredetermined at 25 °C. The partition constants of B15C5were also measured at 25 °C. The log KMLA values for Li+, Na+, and K+ are -0.32 ± 0.22, 2.66 ± 0.19, and 0.71 ± 0.47, respectively. In going from 15-crown-5 (15C5) to B15C5, the benzo group considerably decreasesthe KMLA value for the same alkali metal ion. The distributionbehavior of B15C5 and its 1:1:1 complexes with the alkali metal Picrates closely obeys regularsolution theory, omitting chloroform. Molar volumes and solubility parameters of B15C5and the 1:1:1 complexes were determined. For every diluent, the Kex valuefor B15C5 increases in the order Li+ < K+ < Na+. KD,MLA makes anunfavorable contribution to the Na+ extraction-selectivity of B15C5 because of the smallest molar volume of the Na(B15C5)A complex. The Na+ extraction-selectivity of B15C5 is determined completely by much the highest KNa(B15C5)A value.The extraction-ability and -selectivity of B15C5 for the alkali metal Picrates are compared with those of 15C5on the basis of the underlying equilibrium constants.

Yoshihiro Kudo - One of the best experts on this subject based on the ideXlab platform.

  • Selective Extraction of Lithium with a Macrocyclic Trinuclear Complex of (1,3,5-Trimethylbenzene)ruthenium(II) Bridged by 2,3-Dioxopyridine
    Analytical sciences : the international journal of the Japan Society for Analytical Chemistry, 2008
    Co-Authors: Shoichi Katsuta, Takahiro Imoto, Yoshihiro Kudo, Yasuyuki Takeda
    Abstract:

    A macrocyclic trinuclear complex of (1,3,5-trimethylbenzene)ruthenium(II) bridged by 2,3-dioxopyridine was synthesized, and the extraction properties for lithium and sodium Picrates were investigated in a dichloromethane/water system at 25 degrees C. The complex was found to have extremely high extractability and selectivity for lithium picrate; the logarithmic values of the extraction constants are 5.86 and 2.63 for Li(+) and Na(+), respectively. By using this complex as an extractant, nearly quantitative extraction and separation of Li(+) from Na(+) could be achieved by a single extraction.

  • extraction properties for alkali metal Picrates of macrocyclic trinuclear p cymene ruthenium ii and pentamethylcyclopentadienyl rhodium iii complexes
    Inorganica Chimica Acta, 2008
    Co-Authors: Shoichi Katsuta, Yoshihiro Kudo, Yudai Iwabe, Yayoi Kato, Yasuyuki Takeda
    Abstract:

    Abstract The solvent extraction properties of macrocyclic trinuclear organometallic complexes, [(p-cymene)Ru(pyO2)]3 and [Cp∗Rh(pyO2)]3 ( pyO 2 2 - = 2 , 3 -dioxopyridine, Cp ∗ = pentamethylcyclopentadienyl ) , for Li+, Na+, and K+ Picrates have been investigated in a dichloromethane–water system at 25 °C. The extraction rates of the alkali metal Picrates with these macrocyclic complex ligands are unusually slow; the shaking times required to attain equilibrium are at least 1 h for [(p-cymene)Ru(pyO2)]3 and 20–40 h for [Cp∗Rh(pyO2)]3. From analysis of the equilibrium data, the extraction constants (Kex = [ML+A−]o/[M+][L]o[A−]; M+ = alkali metal ion, L = macrocyclic ligand, A− = picrate ion, o = organic phase) have been determined. The log Kex value varies in the sequences, Li+ (5.72) > Na+ (4.50) > K+ (2.88) for [(p-cymene)Ru(pyO2)]3 and Li+ (4.79) > Na+ (2.70) ≈ K+ (2.69) for [Cp∗Rh(pyO2)]3. The Kex values of 6,6-dibenzyl-14-crown-4 (DBz14C4), which is one of the best Li+-selective crown ethers, have also been determined for comparison. It is revealed that [Cp∗Rh(pyO2)]3 is much superior to DBz14C4 both in the extractability for Li+ and the selectivity for Li+ over Na+.

  • Equilibrium Study on Ion-Pair Formation in Water and Distribution Between Water and m-Xylene of Tetraalkylammonium Picrates
    Journal of Solution Chemistry, 2004
    Co-Authors: Shoichi Katsuta, Takuya Ishitani, Yoshihiro Kudo, Mika Suzuki, Yuki Ishii, Yasuyuki Takeda
    Abstract:

    The 1:1 ion-pair formation constants ( K _IP) of tetraalkylammonium (Me_4N^+, Et_4N^+, Pr_4N^+, Bu_4N^+, and Bu_3MeN^+) Picrates in water were determined by capillary electrophoresis at 25°C. The ion-pair extraction constants ( K _ex,ip) of the Picrates from water to m -xylene were determined by a batch-extraction method at 25°C, and the distribution constants ( K _D) of the neutral ion-pairs were calculated from the relationship K _D = K_ex,ip/ K _IP. The tetraalkylammonium ion having more methylene groups generally forms a slightly more stable ion-pair with the picrate ion in water, which is attributed to the lower hydration of the cation. For Me_4N^+, Et_4N^+, Pr_4N^+, and Bu_4N^+, the distribution of the ion pair into m -xylene increases in that order, and a linear relationship was found between log K _D and the number of methylene groups in the cation. This is consistently explained by the regular solution theory. It was also revealed that the ion pairs have a strong specific interaction with water. The ion pair of Bu_3MeN^+ has a higher distribution constant than that expected from the relationship between log K _D and the number of methylene groups for the symmetrical tetraalkylammonium ions. The cation dependence of the ion pair extractability is mostly governed by that of the distribution of the ion pair.

  • Extraction Equilibria between Benzene and Water of Uni- and Bivalent Metal Picrates with Lariat 16-Crown-5: Effect of the Side Arms on the Extraction Ability and Selectivity
    Journal of inclusion phenomena and molecular recognition in chemistry, 1998
    Co-Authors: Shoichi Katsuta, Yasuyuki Takeda, Yoshihiro Kudo, Tokutaro Kimura, Ryozo Nakagawa, Mikio Ouchi
    Abstract:

    The overall extraction constants (K_ex) of uni- andbivalent metal Picrates with 15-(2,5-dioxahexyl)-15-methyl-16-crown-5(L16C5) were determined between benzene and water at 25°C. TheK_ex values were analyzed into the constituent equilibriumconstants, i.e., the extraction constant of picric acid, the distributionconstant of the crown ether, the stability constant of the metalion–crown ether complex in water, and the ion-pair extraction constantof the complex cation with the picrate anion. The K_ex valuedecreases in the orders Ag^+ > Na^+ >Tl^+ > K^+ > Li^+ andPb^2+ > Ba^2+ > Sr^2+ for theuni- and bivalent metals, respectively, which are the same as those observedfor 16C5. The extraction selectivity was found to be governed by theselectivity of the ion-pair extraction of the L16C5–metal picratecomplex rather than by that of the complex formation in water. Theextraction ability of L16C5 is smaller for all the metals than that of 16C5,which is mostly attributed to the higher lipophilicity of L16C5. Differencesin the extraction selectivity between L16C5 and 16C5 were observed for thebivalent metals but little for the univalent metals. The side-arm effect onthe extraction selectivity was interpreted on the basis of the negativecorrelation between the effect on the complex stability constant in waterand that on the ion-pair extraction constant.

  • solvent extraction of alkali metal li cs Picrates with 18 crown 6 into various diluents elucidation of fundamental equilibria which govern the extraction ability and selectivity
    Analytical Sciences, 1998
    Co-Authors: Yasuyuki Takeda, Tsuyoshi Yahata, Yoshihiro Kudo, Kiyokazu Endo, Atsuhiro Kawarabayashi, Shoichi Katsuta
    Abstract:

    The actual constants of the overall extraction equilibrium, the distribution for various organic solvents having low dielectric constants, and the aqueous ion-pair formation (KMLA) of 18-crown-6 (18C6)-alkali metal (Li-Cs) picrate 1:1:1 complexes were determined at 25°C; the partition constants of 18C6 were also measured at 25°C. The log KMLA values are 2.53±0.21 for Li, 3.29±0.23 for Na, 4.76±0.27 for K, 4.62±0.36 for Rb, and 4.49±0.36 for Cs. The relatively large difference in the log KMLA value between light (Li, Na) and heavy alkali metals (K, Rb, Cs) reflects the difference in the structure of the 18C6-alkali metal ion 1:1 complex between light and heavy alkali metals. Almost all of the partition behavior of 18C6 and its 1:1:1 complexes with alkali metal Picrates can be explained by regular solution theory. The molar volumes and solubility parameters of 18C6 and the complexes were determined. For every diluent, the extraction-selectivity order of 18C6 is K > Rb > Cs > Na > Li. The extraction-ability and -selectivity of 18C6 for the alkali metal ion were completely elucidated in terms of the four fundamental equilibria.

Zhixian Zhou - One of the best experts on this subject based on the ideXlab platform.

  • The crystal structures and spectral behaviour of BENZO-15-CROWN-5 adducts with hydrated lanthanide Picrates
    Polyhedron, 1996
    Co-Authors: Zhixian Zhou, Wen-chao Zheng, Zhi-hua Mao, Zong-hua Zhou, Zhou Hong
    Abstract:

    Abstract -A new series of benzo-15-crown-5 adducts with hydrated lanthanide (La, Pr, Nd, Sm, Eu, Gd, Er) Picrates has been obtained. Elemental analyses indicated that their stoichiometry is 1:2:3 (metal :benzo-15-crown-5 : picrate) except for the lanthanum adduct. X-ray structural analysis of the Nd, Sm and Er adducts revealed that Nd, Sm or Er ions coordinate directly with water molecules and the picrate anion. The benzo-15-crown-5 acts as a second-sphere ligand which associates with the Nd, Sm or Er ion through hydrogen bonding by coordinating water molecules. From investigation of the IR and UV vis spectra of the adducts, it can be deduced that the adducts, except lanthanum, exhibit a similar molecular structure to that of the Nd, Sm and Er adducts. These new adducts may also be classified as supermolecules because each is an associate of two chemical species of hydrated lanthanide picrate and benzo-15-crown-5 held together by coordination water molecules.

  • Studies on the coordination behaviour of 1,3-phenylenebis(formyloxyacetyl-4′-benzo-15-crown-5)
    Polyhedron, 1995
    Co-Authors: Zhixian Zhou, Yingxia Zhou, Kuiling Ding
    Abstract:

    Abstract Yellow solid complexes having the stoichiometric formula KLPic and Na 2 L (Pic) 2 · 2H 2 O (L = 1,3-phenylenebis(formyloxyacetyl-4′-benzo-15-crown-5), Pic = picrate anion) were obtained from chloroform-methanol mixtures. The results of the characterization of the two complexes by IR, NMR, UV-vis spectra and molar conductance indicated that a 2: 1 complex of crown-separated ion pair (benzo-15-crown-5 unit to K + ) and a 1: 1 complex of contact ion pair (benzo-15-crown-5 unit to Na + ) are formed, respectively. 13 C NMR spectra showed that the carbonyl groups on the bridging chain do not take part in the coordination of the Picrates. A PVC membrane K + -selective electrode based on the title ligand (L) was also studied. The 11 kinds of new, coloured, solid rare earth picrate complexes with the stoichiometric formula Ln(Pic) 3 · L · n H 2 O (Ln  La, Pr, Nd, Sm, Eu, Gd, Tb, Ho, Er, Yb, Y, n = 5 or 6) were prepared in an ethanol-chloroform mixture. By elemental analysis, IR, UV-vis spectra, molar conductance and DTA-TG, these complexes were proposed as supermolecules in which the title ligand acts as second-sphere ligand, and Ln(Pic) 3 is associated with the ligand by intermolecular forces.

Sait Erdogan - One of the best experts on this subject based on the ideXlab platform.

  • effect of structural modifications of diaza 18 crown 6 on the extractability and selectivity of univalent metal Picrates
    Talanta, 2001
    Co-Authors: Berrin Ziyadanogullari, Candan Hamamci, Sait Erdogan, Giray Topal, Halil Hosgoren
    Abstract:

    The solvent extraction of univalent metal cations with N,N'-dibenzyl-1,4,10,13-tetraoxa-7,16 diaza-2,3,11,12-dibenzocycloocta deca-2,11-diene (L(1)), N,N' didodecyl-1,4,10,13-tetraoxa-7,16-diaza-2,3-benzocylooctadeca-2 ene (L(2)) and N,N'-dibenzyl-1,4,10,13-tetraoxa-7,16 diaza-2,3,11,12-dibenzocyclo octadeca-2,11-diene (L(3)) with picrate anion into dichloromethane has been studied at 25 degrees C by UV-visible spectroscopy. The extractability and selectivity of univalent metal Picrates (Li(+), Na(+), Ag(+), PhCH(2)NH(3)(+), NH(4)(+)) was evaluated as a function of [ligand]/[metal cation]. L(2) showed the highest extractability and selectivity for Li(+) over the larger studied cations, and also exhibited the highest [Li(+)]/[NH(4)(+)] selectivity as L/M=1.

  • the solvent extraction of alkali metal Picrates with 4 13 n n dibenzyl 4 13 diaza 18 crown 6
    Talanta, 1998
    Co-Authors: Candan Hamamci, Halil Hosgoren, Sait Erdogan
    Abstract:

    Extraction of alkali metal Picrates with N,N%-dibenzyl-18-crown-6 was carried out, with dichloromethane as water-immiscible solvent, as a function [ligand]:[metal cation]. The extractability of metal Picrates (Li ,N a ,K , Rb ,C s) was evaluated as a function of [L]:[M]. The extractability of complex cation‐picrate ion pairs decreases in this sequence: Li\Rb\Cs\K\Na. The overall extraction equilibrium constants (Kex) for complexes of N,N%-dibenzyl-18-crown-6 with alkali metal Picrates between dichloromethane and water have been determined at 25°C. The values of the extraction constants (log Kex) were determined to be 10.05, 6.83, 7.12, 7.83, 6.73 for Li, Na ,K ,R b and Cs compounds, respectively. DB186 shows almost 2-fold extractability against Li compared to the other metal Picrates, whereas it shows no obvious extractability difference amongst the other metal cations when [L]:[M] is 0.2‐1. However, an increasing extractability is observed for Cs when [L]:[M] [1]. © 1998 Elsevier Science B.V. All rights reserved.