The Experts below are selected from a list of 99 Experts worldwide ranked by ideXlab platform

Ryuichi Arakawa - One of the best experts on this subject based on the ideXlab platform.

  • studies on the association of 2 thiazolidinecarboxylic acid and Antimony Potassium Tartrate chiral recognition and prediction of absolute configuration by electrospray ionization mass spectrometry
    Rapid Communications in Mass Spectrometry, 2001
    Co-Authors: Ryuichi Arakawa, Mako Kobayashi, Tsuyoshi Fukuo, Tadashi Shiraiwa
    Abstract:

    Optically active 2-thiazolidinecarboxylic acid (2-THC), a substrate for D-amino acid oxidase in animal kidney, is known to undergo racemization quickly in solution. The association of (+)- and (−)-2-THC with Antimony Potassium Tartrate K2[Sb2(L or D-tart)2] was studied by electrospray ionization mass spectrometry (ESI-MS). We observed that relative intensities of associated ions in acetonitrile/water solution were changing as the racemization progressed. For [Sb2(L-tart)2]2−, the intensities of the associated ions increased as (+)-2-THC underwent racemization to a (−)-isomer; on the other hand, the intensity of the associated ion decreased as (−)-2-THC underwent racemization to a (+)-isomer. In the case of [Sb2(D-tart)2]2−, an opposite effect on the intensities of the associated ions was observed. The change in the intensities of associated ions can be used for chiral recognition of (+)-2-THC and (−)-2THC. Stereochemical models of the association of the optical isomers with [Sb2(L- or D-tart)2]2− were constructed from the consideration of both hydrogen bonding of NH-O functions and HSAB (hard and soft acids and bases) interaction of S and Sb atoms. Comparison of the stereochemical models with the ESI-MS results enabled us to predict the absolute configurations of the 2-THC isomers. Copyright © 2001 John Wiley & Sons, Ltd.

  • chiral recognition in association between Antimony Potassium Tartrate and bis l alaninate ethylenediamine cobalt iii complexes using electrospray ionization mass spectrometry
    Journal of the American Society for Mass Spectrometry, 2000
    Co-Authors: Ryuichi Arakawa, Mako Kobayashi, Tomoharu Ama
    Abstract:

    The chiral recognition of metal complexes by a quick and sensitive mass spectrometric analysis was investigated. The principle is introduction of an external chiral standard compound and detection of the differential association with two optical isomers. Using electrospray ionization mass spectrometry we detected weak intermolecular association between the external chiral anionbis(μ-L-, D-tartrato)-diantimonate(III), [Sb2(L-, D-tart)2]2− and isomeric bis(L-alaninate) ethylenediamine cobalt(III) complex ions, [Co(L-ala)2(en)]+ in acetonitrile/water solution. The difference in the association with optical isomers of the Co complex was measured. The results were interpreted based on a model of intermolecular interaction involving hydrogen bonding. The prospects of the mass spectrometry method for chiral recognition using the external chiral negative ion [Sb2(L-, D-tart)2]2− was discussed.

Tomoharu Ama - One of the best experts on this subject based on the ideXlab platform.

  • chiral recognition in association between Antimony Potassium Tartrate and bis l alaninate ethylenediamine cobalt iii complexes using electrospray ionization mass spectrometry
    Journal of the American Society for Mass Spectrometry, 2000
    Co-Authors: Ryuichi Arakawa, Mako Kobayashi, Tomoharu Ama
    Abstract:

    The chiral recognition of metal complexes by a quick and sensitive mass spectrometric analysis was investigated. The principle is introduction of an external chiral standard compound and detection of the differential association with two optical isomers. Using electrospray ionization mass spectrometry we detected weak intermolecular association between the external chiral anionbis(μ-L-, D-tartrato)-diantimonate(III), [Sb2(L-, D-tart)2]2− and isomeric bis(L-alaninate) ethylenediamine cobalt(III) complex ions, [Co(L-ala)2(en)]+ in acetonitrile/water solution. The difference in the association with optical isomers of the Co complex was measured. The results were interpreted based on a model of intermolecular interaction involving hydrogen bonding. The prospects of the mass spectrometry method for chiral recognition using the external chiral negative ion [Sb2(L-, D-tart)2]2− was discussed.

Mako Kobayashi - One of the best experts on this subject based on the ideXlab platform.

  • studies on the association of 2 thiazolidinecarboxylic acid and Antimony Potassium Tartrate chiral recognition and prediction of absolute configuration by electrospray ionization mass spectrometry
    Rapid Communications in Mass Spectrometry, 2001
    Co-Authors: Ryuichi Arakawa, Mako Kobayashi, Tsuyoshi Fukuo, Tadashi Shiraiwa
    Abstract:

    Optically active 2-thiazolidinecarboxylic acid (2-THC), a substrate for D-amino acid oxidase in animal kidney, is known to undergo racemization quickly in solution. The association of (+)- and (−)-2-THC with Antimony Potassium Tartrate K2[Sb2(L or D-tart)2] was studied by electrospray ionization mass spectrometry (ESI-MS). We observed that relative intensities of associated ions in acetonitrile/water solution were changing as the racemization progressed. For [Sb2(L-tart)2]2−, the intensities of the associated ions increased as (+)-2-THC underwent racemization to a (−)-isomer; on the other hand, the intensity of the associated ion decreased as (−)-2-THC underwent racemization to a (+)-isomer. In the case of [Sb2(D-tart)2]2−, an opposite effect on the intensities of the associated ions was observed. The change in the intensities of associated ions can be used for chiral recognition of (+)-2-THC and (−)-2THC. Stereochemical models of the association of the optical isomers with [Sb2(L- or D-tart)2]2− were constructed from the consideration of both hydrogen bonding of NH-O functions and HSAB (hard and soft acids and bases) interaction of S and Sb atoms. Comparison of the stereochemical models with the ESI-MS results enabled us to predict the absolute configurations of the 2-THC isomers. Copyright © 2001 John Wiley & Sons, Ltd.

  • chiral recognition in association between Antimony Potassium Tartrate and bis l alaninate ethylenediamine cobalt iii complexes using electrospray ionization mass spectrometry
    Journal of the American Society for Mass Spectrometry, 2000
    Co-Authors: Ryuichi Arakawa, Mako Kobayashi, Tomoharu Ama
    Abstract:

    The chiral recognition of metal complexes by a quick and sensitive mass spectrometric analysis was investigated. The principle is introduction of an external chiral standard compound and detection of the differential association with two optical isomers. Using electrospray ionization mass spectrometry we detected weak intermolecular association between the external chiral anionbis(μ-L-, D-tartrato)-diantimonate(III), [Sb2(L-, D-tart)2]2− and isomeric bis(L-alaninate) ethylenediamine cobalt(III) complex ions, [Co(L-ala)2(en)]+ in acetonitrile/water solution. The difference in the association with optical isomers of the Co complex was measured. The results were interpreted based on a model of intermolecular interaction involving hydrogen bonding. The prospects of the mass spectrometry method for chiral recognition using the external chiral negative ion [Sb2(L-, D-tart)2]2− was discussed.

Tadashi Shiraiwa - One of the best experts on this subject based on the ideXlab platform.

  • studies on the association of 2 thiazolidinecarboxylic acid and Antimony Potassium Tartrate chiral recognition and prediction of absolute configuration by electrospray ionization mass spectrometry
    Rapid Communications in Mass Spectrometry, 2001
    Co-Authors: Ryuichi Arakawa, Mako Kobayashi, Tsuyoshi Fukuo, Tadashi Shiraiwa
    Abstract:

    Optically active 2-thiazolidinecarboxylic acid (2-THC), a substrate for D-amino acid oxidase in animal kidney, is known to undergo racemization quickly in solution. The association of (+)- and (−)-2-THC with Antimony Potassium Tartrate K2[Sb2(L or D-tart)2] was studied by electrospray ionization mass spectrometry (ESI-MS). We observed that relative intensities of associated ions in acetonitrile/water solution were changing as the racemization progressed. For [Sb2(L-tart)2]2−, the intensities of the associated ions increased as (+)-2-THC underwent racemization to a (−)-isomer; on the other hand, the intensity of the associated ion decreased as (−)-2-THC underwent racemization to a (+)-isomer. In the case of [Sb2(D-tart)2]2−, an opposite effect on the intensities of the associated ions was observed. The change in the intensities of associated ions can be used for chiral recognition of (+)-2-THC and (−)-2THC. Stereochemical models of the association of the optical isomers with [Sb2(L- or D-tart)2]2− were constructed from the consideration of both hydrogen bonding of NH-O functions and HSAB (hard and soft acids and bases) interaction of S and Sb atoms. Comparison of the stereochemical models with the ESI-MS results enabled us to predict the absolute configurations of the 2-THC isomers. Copyright © 2001 John Wiley & Sons, Ltd.

M. Vithal - One of the best experts on this subject based on the ideXlab platform.

  • Antimony Potassium Tartrate
    Journal of Thermal Analysis and Calorimetry, 2013
    Co-Authors: J. R. Reddy, G. Ravi, P. Suresh, Naveen Kumar Veldurthi, Radha Velchuri, M. Vithal
    Abstract:

    Single source precursor, Antimony Potassium Tartrate, was used for the preparation of Sb2O3, KSb3O5, K0.51Sb0.67IIISb2VO6.26, and KSbO3. Antimony trioxide (Sb2O3) was prepared by hydrothermal method, while Potassium Antimony oxides (KSbO3, K0.51Sb0.67IIISb2VO6.26, and KSbO3) were obtained from the thermal decomposition of Antimony Potassium Tartrate. All the compounds were characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FT-IR), UV–Vis diffuse reflectance spectra, and scanning electron microscopy (SEM). The decomposition process of Antimony Potassium Tartrate with temperature was given. The product formation at different temperatures of thermal decomposition was monitored by PXRD and FT-IR. The TG profile of Antimony Potassium Tartrate shows mass loss at three regions. The infrared spectra of parent and decomposed products gave characteristic Sb-O bands. The band gap energy of decomposed products was obtained. The SEM diagrams of Sb2O3 show different morphologies. Direct solid state preparation of KSb3O5 and K0.51Sb0.67IIISb2VO6.26 under identical experimental conditions was unsuccessful.