Design of benzo-15-crown-5 azoprobe/γ-cyclodextrin complexes for alkali metal ion recognition in water
Fecha
2010Autor
Hayashita, Takashi
Fujita, Dai
Hashimoto, Takeshi
Endo, Akira
Zhao, Hui (TTU)
Odagiri, Kayo
Takahashi, Shu
Mohamad, Murad M.
Teramae, Norio
Metadatos
Mostrar el registro completo del ítemResumen
Novel photosignal transduction systems of benzo-15-crown-5 (B15C5) azoprobe/γ-cyclodextrin
(γ-CyD) complexes were designed. Four B15C5 azoprobes were synthesized by azo coupling of
4’-aminobenzo-15-crown-5 with phenol (for 15C5-Az-Ph) and N,N-dialkylanilines (for 15C5-
Az-Cn). These azoprobes exhibited strong induced circular dichroism (ICD) by forming an
inclusion complex with γ-CyD. Examination of the spectral responses and 1H NMR analysis of
the B15C5 azoprobe/γ-CyD complexes in the presence of alkali metal cations revealed that K
+
binding selectively induced dimer formation of the B15C5 azoprobes inside the γ-CyD cavity,
which resulted in distinct changes in their UV-vis and ICD spectra in water. The effect of alkyl
chain length of 15C5-Az-Cn n γ-CyD complexes was examined in 90% H2O/10%
CH3CN (v/v). The highest K+
ion response was noted for the 15C5-Az-C2γ-CyD complex. The
15C5-Az-C4γ-CyD complex was found to show abnormally high ICD responses for TMA+
and
Cs+.