| 研究概要 |
1. SYSTEMATIC MEASUREMENTS OF ^<183>W NMR ON AQUEOUS SOLUTIONS OF KEGGIN-TYPE HETEROPOLYTUNGSTATES HAVE BEEN CARRIED OUT, STRUCTURE DEPENDENCE OF ^<183>W CHEMICAL SHIFT AND CORRELATION BETWEEN CHEMICAL SHIFT AND THERMAL PARAMETERS BEEING TESTED. THE DATA COLLECTION FOR THIS PROJECT DOES NOT YET COMPLETE, AND IS IN PROGRESS.
2. ^<31>P,^<51>V,^<77>SE ＆ ^<183>W NMR SPECTRA OD AQUEOUS SOLUTIONS CONTAINING NON-KEGGIN-TYPE POLYOXOMETALATES WITH KNOWN STRUCTURES HAVE BEEN OBSERVED IN ORDER TO INVESTIGATE THE EQUILIBRIA. THE SINGLE CRYSTALS ISOLATED FROM ABOVE-MENTIONED SOLUTION HAVE BEEN SUBJECTED TO X-RAY DIFFRACTION STUDIES AND THEIR STRUCTURES WERE DETERMINED.
(1) H^+-MoO_4^<2->-SeO_3^<2-> AND H^+-VO_4^--SeO_3^<2->. CHEMICAL SPECIES IN SOLUTIONS AND STRUCTURES OF CRYSTALS OBTAINED FROM THE AQUEOUS SYSTEMS HAVE BEEN DETEMINED. IN THE FORMER SYSTEM, ^<77>Se NMR AND POTENTIOMETRY AGREED WELL WITH EACH OTHER. THE PROPOSED STRUCTURE WAS CONFIRMED BY USE OF SINGLE CRYSTAL X-RAY DIFFRACTION. THE SO
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LUTION DISSOLVING THE CRYSTAL SHOWED A ^<77>Se NMR SPECTRA CONSISTENT WITH THOSE OBSERVED IN SYSTEMATIC MEASUREMENTS ON THE AQUEOUS SYSTEM. ON THE OTHER HAND, THERE WERE NO HETROPOLYVANADATES DETECTED IN THE LATTER SYSTEM, ANDDECAVANADATE, METAVANADATE AND SELENITE IONS WERE FOUND TO BE PREDOMINANT SPECIES THROUGH THE REGION MEASURED. THE STRUCTURE OF THE CRYSTAL OBTAINED FROM THIS SYSTEM REVEALED THE HETEROPOLYVANADATE TO BE A NOVEL TYPE, AND ITS CONSTITUTION WAS NOT AGREED WITH THOSE DESCRIBED IN THE LITERATURES.
(2) H^+-MoO_4^<2->-HPO_3^<2->. ^<31>P NMR OF THE SYSTEM HAS BEEN MEASURED AND THE STRUCTURE OF CRYSTAL ISOLATED FROM THIS SYSTEM WERE DETERMINED. THE HETEROPOLYANION WAS PROVED TO HAVE NON-ACIDIC PROTONS LIKE AS PHOSPHITE ION.
3. FINDINGS OF NOVEL PEROXOTUNGSTATES. AMORPHOUS "CWHPA" DIRECTLY FORM THE REACTION OF TUNGSTENCARBIDE AND HYDROGEN PEROXIDE HAS BEEN REPRODUCED BY MIXTURES OF TUNGSTATE, OXALATE AND HYDROGEN PEROXIDE IN AQUEOUS SYSTEM, ^<13>C NMR, IR AND RAMAN SPECTRA BEING APPLIED. COMPARISON OF CRYSTAL STRUCTURES AND CHEMICAL SHIFTS OF NMR REVEALED DIFFERENT GEOMETRIES ABOUT C-O BONDS TO GIVE DISTINCT ^<13>C NMR CHEMICAL SHIFTS. THIS PROJECT IS ALSO UNDER FURTHER CONSTRUCTION. 隠す
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