Y. Matsushita, Tadashi Suzuki, T. Ichimura
Aug 21, 2004
Citations
1
Influential Citations
11
Citations
Journal
Journal of Physical Chemistry A
Abstract
The effect of cyclodextrin (CD) complexation on the fluorescence properties of methyl 4-(dimethylamino)benzoate (MDMAB) was studied. The complex with R-, ‚-, and A-CDs exhibited twisted intramolecular charge transfer (TICT) fluorescence whereas only the emission from the locally excited state was observed in aqueous solution without CD. In the case of the R-CD complex, dual TICT emission was observed, a low-energy emission was centered at 520 nm, and a higher-energy emission was centered at 450 nm. The dependence of TICT emission intensity on pH and R-CD concentration suggested that the lower and higher energy emission can be attributed to the TICT states of MDMAB in the 1:1 and 1:2 MDMAB-R-CD complexes. On the other hand, only the formation of 1:1 complex was observed in the presence of ‚- and A-CDs. The cavity size effect on the fluorescence properties of MDMAB was further discussed on the basis of time-resolved laser spectroscopy.