Tsutomu Tahara

Liquefaction of subbituminous coals under apparently non-hydrogenative conditions

Abstract Reactivities of several coals of different ranks have been examined in degrading extractions with aromatic solvents under apparently non-hydrogenative reaction conditions. Pyrene and A240 pitch liquefied the fusible coals in high yields and the slightly-fusible coals in moderate yields, indicating the importance of fusibility in such liquefaction processes. A240-LS pitch is a powerful solvent for slightly-fusible coals. Considerable amounts of pyridine- or THF-soluble fractions were produced especially with A240-LS pitch. A240 pitch is a better solvent than pyrene for some slightly-fusible coals. However, the extent of depolymerization of liquefied coal, pyridine- or THF-solubility, was definitely inferior. Yields of such fractions are higher for lower-rank coals. The mechanism of coal liquefaction under apparently non-hydrogenative conditions is discussed with emphasis on the stabilization of thermal fragments derived from the coal.

DEPENDENCE OF GUEST-BINDING ABILITY ON CAVITY SHAPE OF DEFORMED CYCLODEXTRINS

Abstract Guest-binding ability of some β-cyclodextrin derivatives with deformed cavities were dependent on the cavity shapes, where 2,3′-anhydro-β-cyclodextrin 3 bound methyl orange about 2.8 times stronger than native β-cyclodextrin at 10°C.

Synthesis and structure determination of 3A,6X-Di-O-arenesulfonyl-∝-cyclodextrins

Abstract A regioisomeric mixture of 3 A -O-(β-naphthylsulfonyl)-6 X -O- mesitylsulfonyl-∝-cyclodextrins (X = A−F) was prepared by the reaction of 3- O-(β-naphthylsulfonyl)-α-cyclodextrin with mesitylenesulfonyl chloride in pyridine. Each isomer was isolated and assigned.

A complete set of 3A,6X-di-O-sulfonylated α-cyclodextrins

Abstract Each of 3A-O-(2-naphthalenesulfonyl)-6X-O-(mesitylenesulfonyl)-α-cyclodextrins (X B, C, E, or F), which was prepared by the reaction of 3A-O-(2-naphthalenesulfonyl)-α-cyclodextrin with mesitylenesulfonyl chloride, was structurally determined through combination of chemical derivation and enzymatic hydrolysis.