The Experts below are selected from a list of 14265 Experts worldwide ranked by ideXlab platform
Sanjeevan J. Kharat - One of the best experts on this subject based on the ideXlab platform.
-
partial molar volume jones dole coefficient and limiting molar isentropic compressibility of sodium ibuprofen in water and its Hydration Number and Hydration free energy
Thermochimica Acta, 2013Co-Authors: Sanjeevan J. KharatAbstract:Abstract The article reports densities, viscosities, and ultrasonic velocities of solutions of sodium ibuprofen in water at T = 298.15, 303.15, 308.15, and 313.15 K and at atmospheric pressure. The molality range has been studied from 0.1048 to 0.4678 mol kg−1. Partial molar volume, Jones–Dole coefficient, isentropic compressibility at infinite dilution, and Hydration Number have been calculated from measured data. Due to the importance of calculation of Hydration free energy of drugs in the research of pharmaceuticals and agrochemical industries, the Hydration free energy of sodium ibuprofen at 298.15 K has also been computed theoretically. Results have been discussed in terms of solute–solvent interactions.
-
Partial molar volume, Jones–Dole coefficient, and limiting molar isentropic compressibility of sodium ibuprofen in water and its Hydration Number and Hydration free energy
Thermochimica Acta, 2013Co-Authors: Sanjeevan J. KharatAbstract:Abstract The article reports densities, viscosities, and ultrasonic velocities of solutions of sodium ibuprofen in water at T = 298.15, 303.15, 308.15, and 313.15 K and at atmospheric pressure. The molality range has been studied from 0.1048 to 0.4678 mol kg−1. Partial molar volume, Jones–Dole coefficient, isentropic compressibility at infinite dilution, and Hydration Number have been calculated from measured data. Due to the importance of calculation of Hydration free energy of drugs in the research of pharmaceuticals and agrochemical industries, the Hydration free energy of sodium ibuprofen at 298.15 K has also been computed theoretically. Results have been discussed in terms of solute–solvent interactions.
Yuko Hasegawa - One of the best experts on this subject based on the ideXlab platform.
-
DeHydration from tris[β-diketonato]lanthanoids(III) on the 1,10-phenanthroline adduct formation across lanthanoid series
Analytica Chimica Acta, 2001Co-Authors: Yuko Hasegawa, Mitsunobu Miratsu, Gregory R. ChoppinAbstract:Abstract The residual Hydration Number of the metal ion in the 1,10-phenanthroline adducts of tris[1,1,1-trifluoro-5,5′-dimethyl-2,4-hexanedionato]lanthanoids in chloroform has been determined by coulometric Karl–Fischer titration and also by the luminescence lifetime of europium(III) in the complex. The residual Hydration Number was essentially zero for all lanthanoids across the series. This data and the Hydration Number of the lanthanoids(III) complexed with the β-diketone can be used to explain the trend of the variation of the formation constants of the adducts across the lanthanoid series.
-
Trend of variation of Hydration Number of tris[β-diketonato]lanthanoids(III) in chloroform across lanthanoid series
Inorganica Chimica Acta, 2000Co-Authors: Yuko Hasegawa, Mitsunobu Miratsu, Takayuki KondoAbstract:Abstract The Hydration Number of tris[pivaloyltrifluoroacetonato]lanthanoids(III) (Ln(PTA) 3 ) has been determined across the lanthanoid series on the basis of the water content in the Ln(PTA) 3 /chloroform solution saturated with water measured by Karl–Fischer coulometory. The Hydration Number of Ln(PTA) 3 was between 2.0 and 2.5 across the series. The Number seems to increase slightly from La to around Tb, and then decrease towards the heavy lanthanoids. It may reflect the change in the size as well as in charge density of lanthanoids(III).
-
Hydration Number of tris[1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato]lanthanoids in chloroform across the lanthanoid series
Analytical Chemistry, 1999Co-Authors: Yuko Hasegawa, And Eiichi Ishiwata, Tadahiro Ohnishi, G. R. ChoppinAbstract:The Hydration Numbers of lanthanoid(III) chelates with 2-thenoyltrifluoroacetone prepared by extracting into chloroform have been determined by analyzing the relation between lanthanoid(III) concentration and water content. The water contents were measured by coulometric Karl Fischer titration, and the concentration of lanthanoid(III) extracted was determined by ICP/AES. The Hydration Number of europium(III) chelate was also checked by measuring the luminescence lifetime. The Hydration Number is about 3 from lanthanum to holmium and then decreases to about 2.4. The change reflects the variation in the lanthanoid(III) ionic size. The Hydration Number of Eu(TTA)3 obtained by the Karl Fischer titration agrees with that from measurement of the luminescence lifetime, within experimental accuracy.
Yoshiharu Kato - One of the best experts on this subject based on the ideXlab platform.
-
Luminescence study on the inner-sphere Hydration Number of lanthanide(III) ions in concentrated aqueous salt solutions in fluid and frozen states
Journal of Alloys and Compounds, 1998Co-Authors: Takaumi Kimura, Yoshiharu KatoAbstract:Luminescence lifetimes of lanthanide[Ln](III) ions [Ln=Sm, Eu, Tb and Dy] in concentrated aqueous solutions at room and at liquid nitrogen temperatures were measured by means of time-resolved laser-induced luminescence spectroscopy. The inner-sphere Hydration Number NH2O of Ln(III) was estimated on the basis of the correlation between the NH2O and the lifetime obtained in D2O–H2O solutions at each temperature. In fluid states of sodium chloride, nitrate and perchlorate solutions at room temperature, the NH2O of the Ln(III) ions indicate that nitrate ion forms inner-sphere complex with these ions, whereas chloride and perchlorate ions do not, and that the concentrated perchlorate ion would perturb the Hydration structure of Ln(III). In frozen states of the solutions at liquid nitrogen temperature, the formation of the inner-sphere chloro and nitrate complexes of Ln(III) is suggested in chloride and nitrate solutions, respectively, but not in perchlorate solution.
-
Luminescence study on determination of the inner-sphere Hydration Number of Am(III) and Nd(III)
Journal of Alloys and Compounds, 1998Co-Authors: Takaumi Kimura, Yoshiharu KatoAbstract:Abstract A correlation between the luminescence decay constant k obs (the reciprocal of the excited state lifetime) and the inner-sphere Hydration Number N H 2 O of Am(III) and Nd(III) in aqueous solution was investigated to establish a method for determining the N H 2 O from measurements of the luminescence lifetime. The calibration relations were proposed on the basis of the linear correlation of the k obs vs. volume percentage of H 2 O in D 2 O–H 2 O solutions and the N H 2 O in H 2 O, i.e. nine for Am(III) and Nd(III). The k obs of Am(III) and Nd(III) complexed with a series of polyaminopolycarboxylate ligands in H 2 O and D 2 O were measured to validate the calibration relations, and the N H 2 O and coordination Numbers of these ions in the complexes were evaluated and compared with the other luminescent ions systematically.
-
Luminescence study on determination of the Hydration Number of Sm(III) and Dy(III)
Journal of Alloys and Compounds, 1995Co-Authors: Takaumi Kimura, Yoshiharu KatoAbstract:Abstract A luminescence study of Ln(III) ion has revealed a linear correlation between the decay constant kobs (the reciprocal of the excited-state lifetime) and the Number of water molecules nH2O in the first coordination sphere of complexes. From measurements of kobs of Ln(III) in D2OH2O solutions and of Ln(BrO3)3 · 9H2O, the nH2O of Sm(III) and Dy(III) in H2O were calculated to be 9.0 ± 0.5 and 8.4 ± 0.4 respectively. Using Ln(III) complexes of polyaminopolycarboxylate ligands, empirical formulae for the calibration of kobs (ms−1) vs. nH2O were proposed as nH2O = 0.026kobs − 1.6 for Sm(III) and nH2O = 0.024kobs − 1.3 for Dy(III).
Takaumi Kimura - One of the best experts on this subject based on the ideXlab platform.
-
Luminescence Study on the Inner‐Sphere Hydration Number of Lanthanide(III) Ions in Neutral Organo‐Phosphorus Complexes
Solvent Extraction and Ion Exchange, 2004Co-Authors: Ping Zhang, Takaumi Kimura, Zenko YoshidaAbstract:Abstract Time‐resolved laser‐induced fluorescence spectroscopy (TRLFS) was employed to determine the inner‐sphere (i.e., first coordination sphere) Hydration Number (N H2O) of lanthanide(III) ions (Ln = Sm, Eu, Tb, and Dy) in the TRPO‐dodecane/HNO3 (or HNO3–NaNO3) system under various conditions. In addition, the N H2O of Ln(III) in extracted complexes with octyl(phenyl)‐N,N‐diisobutylcarbamoylmethyl phosphine oxide (CMPO), dihexyl‐N,N‐diethylcarbamoylmethyl phosphonate (CMP), trioctyl phosphine oxide (TOPO), and tributyl phosphate (TBP) were also determined. The results show that there is no water molecule in the first coordination sphere of Ln(III) complexes, except for Sm(III) and Dy(III) in CMP complexes.
-
luminescence study on the inner sphere Hydration Number of lanthanide iii ions in neutral organo phosphorus complexes
Solvent Extraction and Ion Exchange, 2004Co-Authors: Ping Zhang, Takaumi Kimura, Zenko YoshidaAbstract:Abstract Time‐resolved laser‐induced fluorescence spectroscopy (TRLFS) was employed to determine the inner‐sphere (i.e., first coordination sphere) Hydration Number (N H2O) of lanthanide(III) ions (Ln = Sm, Eu, Tb, and Dy) in the TRPO‐dodecane/HNO3 (or HNO3–NaNO3) system under various conditions. In addition, the N H2O of Ln(III) in extracted complexes with octyl(phenyl)‐N,N‐diisobutylcarbamoylmethyl phosphine oxide (CMPO), dihexyl‐N,N‐diethylcarbamoylmethyl phosphonate (CMP), trioctyl phosphine oxide (TOPO), and tributyl phosphate (TBP) were also determined. The results show that there is no water molecule in the first coordination sphere of Ln(III) complexes, except for Sm(III) and Dy(III) in CMP complexes.
-
Luminescence study on the inner-sphere Hydration Number of lanthanide(III) ions in concentrated aqueous salt solutions in fluid and frozen states
Journal of Alloys and Compounds, 1998Co-Authors: Takaumi Kimura, Yoshiharu KatoAbstract:Luminescence lifetimes of lanthanide[Ln](III) ions [Ln=Sm, Eu, Tb and Dy] in concentrated aqueous solutions at room and at liquid nitrogen temperatures were measured by means of time-resolved laser-induced luminescence spectroscopy. The inner-sphere Hydration Number NH2O of Ln(III) was estimated on the basis of the correlation between the NH2O and the lifetime obtained in D2O–H2O solutions at each temperature. In fluid states of sodium chloride, nitrate and perchlorate solutions at room temperature, the NH2O of the Ln(III) ions indicate that nitrate ion forms inner-sphere complex with these ions, whereas chloride and perchlorate ions do not, and that the concentrated perchlorate ion would perturb the Hydration structure of Ln(III). In frozen states of the solutions at liquid nitrogen temperature, the formation of the inner-sphere chloro and nitrate complexes of Ln(III) is suggested in chloride and nitrate solutions, respectively, but not in perchlorate solution.
-
Luminescence study on determination of the inner-sphere Hydration Number of Am(III) and Nd(III)
Journal of Alloys and Compounds, 1998Co-Authors: Takaumi Kimura, Yoshiharu KatoAbstract:Abstract A correlation between the luminescence decay constant k obs (the reciprocal of the excited state lifetime) and the inner-sphere Hydration Number N H 2 O of Am(III) and Nd(III) in aqueous solution was investigated to establish a method for determining the N H 2 O from measurements of the luminescence lifetime. The calibration relations were proposed on the basis of the linear correlation of the k obs vs. volume percentage of H 2 O in D 2 O–H 2 O solutions and the N H 2 O in H 2 O, i.e. nine for Am(III) and Nd(III). The k obs of Am(III) and Nd(III) complexed with a series of polyaminopolycarboxylate ligands in H 2 O and D 2 O were measured to validate the calibration relations, and the N H 2 O and coordination Numbers of these ions in the complexes were evaluated and compared with the other luminescent ions systematically.
-
Luminescence study on determination of the Hydration Number of Sm(III) and Dy(III)
Journal of Alloys and Compounds, 1995Co-Authors: Takaumi Kimura, Yoshiharu KatoAbstract:Abstract A luminescence study of Ln(III) ion has revealed a linear correlation between the decay constant kobs (the reciprocal of the excited-state lifetime) and the Number of water molecules nH2O in the first coordination sphere of complexes. From measurements of kobs of Ln(III) in D2OH2O solutions and of Ln(BrO3)3 · 9H2O, the nH2O of Sm(III) and Dy(III) in H2O were calculated to be 9.0 ± 0.5 and 8.4 ± 0.4 respectively. Using Ln(III) complexes of polyaminopolycarboxylate ligands, empirical formulae for the calibration of kobs (ms−1) vs. nH2O were proposed as nH2O = 0.026kobs − 1.6 for Sm(III) and nH2O = 0.024kobs − 1.3 for Dy(III).
Gregory R. Choppin - One of the best experts on this subject based on the ideXlab platform.
-
DeHydration from tris[β-diketonato]lanthanoids(III) on the 1,10-phenanthroline adduct formation across lanthanoid series
Analytica Chimica Acta, 2001Co-Authors: Yuko Hasegawa, Mitsunobu Miratsu, Gregory R. ChoppinAbstract:Abstract The residual Hydration Number of the metal ion in the 1,10-phenanthroline adducts of tris[1,1,1-trifluoro-5,5′-dimethyl-2,4-hexanedionato]lanthanoids in chloroform has been determined by coulometric Karl–Fischer titration and also by the luminescence lifetime of europium(III) in the complex. The residual Hydration Number was essentially zero for all lanthanoids across the series. This data and the Hydration Number of the lanthanoids(III) complexed with the β-diketone can be used to explain the trend of the variation of the formation constants of the adducts across the lanthanoid series.
-
Luminescence study on determination of the Hydration Number of Cm(III)
Journal of Alloys and Compounds, 1994Co-Authors: Takaumi Kimura, Gregory R. ChoppinAbstract:A luminescence study of Cm(III) has shown a linear correlation between the decay constant kobs (the reciprocal of the excited-state lifetime) and the Number of water molecules nH2o in the first coordination sphere of complexes. From measurements of kobs of Cm3+ in D2OH2O solutions and of Cm(III) doped lanthanum compounds, the following correlation for kobs (ms−1) vs. nH2o was established: nH2o = 0.65kobs − 0.88. This relationship was applied to study of the residual Hydration of Cm(III) complexes of polyaminopolycarboxylate ligands. The Hydration Number of Cm(III) in these complexes is apparently larger than that of Eu(III).
