| dc.description.abstract | Abstract
In this thesis, we report the design and synthesis of four new ICT-based intrinsic fluoroionophores 1-Py, 1-Ph, 1-PM, and 1-FM, which use monoaza-15-crown-5 (A15C5) as the ionophore and aminostilbene as the fluorophore. For comparison, we also investigated the known compound 1-Me.
Except for 1-FM, compound series number one (1-Py, 1-Ph, 1-PM, 1-FM, and 1-Me) display fluorescence shifts in response to Ca2+ in acetonitrile. The fluorescence of compound 1-Py is blue-shifted, whereas it is red-shifted for the other three compounds. On the other hand, all five compounds display blue shift in their absorption spectra. Although the spectral responses are distinct, the resulting complexes display a spectroscopic behavior, including the absorption and emission shape and energy, fluorescence quantum yield, and fluorescence lifetime, similar to the corresponding compound series number three (3-Py, 3-Ph, 3-PM, 3-FM, and 3-Me). In dichloromethane, the complexation between compound series number one and Na+ also results in a photochemical behavior similar to the compound series number three. Such correlations indicate that A15C5/Ca2+ in acetonitrile and A15C5/Na+ in dichloromethane have an electronic effect nearly equivalent to a chloro substituent. Since the similarities exist in both absorption and emission spectra in all five fluoroionophores, this suggests that the excited-state decoordination reaction does not occur in all cases. The observed correlations might serve as a useful guide for future probe design. Furthermore, we can gain insights into the electronic structures of the complexes (supramolecular entities) based on the studies of their correlated molecules. | en_US |