The UV absorption and fluorescence spectra of 1,3-di (α-naphthyl) propane (1), di (α- naphthylmethyl) ether (2), and α-methylnaphthalene (3) in aqueous methanol, ethanol, and DMSO were recorded as a function of Φ ...The UV absorption and fluorescence spectra of 1,3-di (α-naphthyl) propane (1), di (α- naphthylmethyl) ether (2), and α-methylnaphthalene (3) in aqueous methanol, ethanol, and DMSO were recorded as a function of Φ value (fraction of water in binary solvents). The existence of two sta- tes, a metastable state (defined as m) and a stable stationary state (defined as s), of molecules 1 as well as 2 in the above cosolvents at high Φ was shown by the contrary fluorescence excimer to monomer intensity (Ie/Im)vs. Φ relationships of the samples prepared with different processes. On the basis of the Φ value, substrate concentration, and the temperature dependence of the UV spectra. fluores- cence excitation and emission spectra, the chromophores of 1, 2 show the formation of aggregates in ground state at high Φ owing to the hydrophobic interaction. The m states consist of a supersaturated solution with aggregates, whereas the s states are suspended microcrystals or micro-oil-droplets with aggregates. The conformations of the molecules in the aggregates were discussed. Single crystal X-ray structure of 2 is reported.展开更多
基金This work was supported by the National Natural Science Foundation of Chinathe National Education Commission Foundation of China.
文摘The UV absorption and fluorescence spectra of 1,3-di (α-naphthyl) propane (1), di (α- naphthylmethyl) ether (2), and α-methylnaphthalene (3) in aqueous methanol, ethanol, and DMSO were recorded as a function of Φ value (fraction of water in binary solvents). The existence of two sta- tes, a metastable state (defined as m) and a stable stationary state (defined as s), of molecules 1 as well as 2 in the above cosolvents at high Φ was shown by the contrary fluorescence excimer to monomer intensity (Ie/Im)vs. Φ relationships of the samples prepared with different processes. On the basis of the Φ value, substrate concentration, and the temperature dependence of the UV spectra. fluores- cence excitation and emission spectra, the chromophores of 1, 2 show the formation of aggregates in ground state at high Φ owing to the hydrophobic interaction. The m states consist of a supersaturated solution with aggregates, whereas the s states are suspended microcrystals or micro-oil-droplets with aggregates. The conformations of the molecules in the aggregates were discussed. Single crystal X-ray structure of 2 is reported.
