Takashi Funaki

Seiichi Inokuma; Koichi Kimura; Takashi Funaki; Jun Nishimura

Azacrownophanes were efficiently prepared by the irradiation of precursor ammonium chlorides in the presence of γ-CD (γ-cyclodextrin) in aqueous solution, by repressing the amino group-quenching effect by inclusion of the styrene moieties in γ-CD. In liquid–liquid extraction, azacrownophanes (6 and 7) showed affinity toward both Ag+ and Pb2+ cations in a series of heavy metal nitrates. Both 6 and 7 formed 1:1 complexes with the above two cations, according to 13C NMR titration and ESI-MS analysis.

Jun Nishimura; Seiichi Inokuma; Takashi Funaki; Daisuke Hara

A new series of crown compounds bearing two carboxyl groups (2a-c; crownophanedicarboxylic acids) were prepared via intramolecular [2 + 2] photocycloaddition of bis-styrene derivatives. In the liquid-liquid extraction, crownophanedicarboxylic acids (2a-c) showed a low affinity toward alkali metal cations, though both 2b and 2c showed an extraordinary high affinity toward zinc cation among heavy metal cations examined.

Jun Nishimura; Seiichi Inokuma; Susumu Nishio; Takashi Funaki; Norio Atarashi; Tetsuya Shirakawa

Amphiphilic podand (3) was prepared by conventional thioether synthesis in ethanol. It shows exclusive selectivity toward Ag + ion in a liquid-liquid extraction. It was also found to exhibit selective fluorescence decrease only in the presence of Ag + ion in water. From the fluorometric titration, the complexing stability constant toward Ag + in water estimated to be log Ka = 4.2, which value is comparable to cyclic dithia-18-crown-6. This extraordinarily high value was caused by a pseudo cyclic structure formed in water, which was supported by 1 H NMR spectral analysis.

Seiichi Inokuma; Hayato Ide; Tomomi Yonekura; Takashi Funaki; Shinichi Kondo; Satoru Shiobara; Toshitada Yoshihara; Seiji Tobita; Jun Nishimura

Seiichi Inokuma; Takashi Funaki; Shinichi Kondo; Jun Nishimura

Seiichi Inokuma; Tomohiro Sakaizawa; Takashi Funaki; Tomomi Yonekura; Hiroko Satoh; Shinichi Kondo; Yosuke Nakamura; Jun Nishimura

Jun Nishimura; Seiichi Inokuma; Koichi Kimura; Takashi Funaki

Takashi Funaki; Seiichi Inokuma; Hayato Ide; Tomomi Yonekura; Yosuke Nakamura; Jun Nishimura

Jun Nishimura; Seiichi Inokuma; Koichi Kimura; Takashi Funaki

Jun Nishimura; Takashi Funaki; Noriaki Saito; Seiichi Inokuma; Yosuke Nakamura; So Tajima; Toshitada Yoshihara; Seiji Tobita