| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1993: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1992: ¥600,000 (Direct Cost: ¥600,000)
|
|---|
| Research Abstract |
(1) Thermal decomposition reactions of thiamine chloride gave at least four pyrimidinium-oligomers, which were detected by HPLC and were successfully separated by a column-chromatography. Investigations of the isolation of the oligomers and their characterization are under way.
(2) Aion salts of a methylene-bridged cationic pyrimidinium-dimer were synthesized, where anions are ClO_4^-, [Hg_2I_6]^<2->, or [Co(SCN)_4]^<2->. X-ray structure analyzes of the salts show that an anion molecule(s) is captured by a cationic pyrimidinium-dimer molecule(s) through (i) a C(pyrimidinium ring)-H...anion hydrogen-bonding and (ii) and anion...pyrimidinium-ring electrostatic interaction. These cation-anion interaction modes are analogous to those found in a chloride salt of cyclic pyrimidinium-tetramer (J.Am.Chem.Soc., 113, 7033 (1991)).
(3) X-ray structure analyzes of anion salts of a thiaminium cation, where anions are [Hg(SCN)_4]^<2->, [PtCl_6]^<2->, [PtCl_6]_<0.5>^-.Cl^-, [Pt(SCN)_4]^<2->, or [Pt(SCN)_6]^<2->, show that these salts also involve the same cation-anion interaction modes as those found in (2).
(4) X-ray structure analyzes of a thiaminium-monophosphate cation, where anions are CF_3SO_3^- or ClO_4^-, show that these salts also involve the same cation-anion interaction modes as those found in (2).
(5) Based on (2), (3) and (4), a principle of cation-anion recognition mechanism is presented, that is, (i) C(aromatic ring)-H...anion hydrogen-bonding and (ii) an anion...aromatic ring electrostatic interaction.
|
