| Summary: | 碩士 === 國立臺北科技大學 === 有機高分子研究所 === 95 === We have synthesized a series of highly fluorinated bipyridine derivatives 4,4 ''-bis(RfCH2OCH2)- 2,2''- bpy { Rf=C8F17(1a), C9F19(1b), C10F21(1c) and C11F23(1d)} by using (4,4′-bis(BrCH2)-2,2′-bpy) and fluorinated sodium alkoxide via the nucleophilic substitution reactions. The yield is very high and the product is easy to purify. These compounds can be analyzed by GC-MASS, NMR, FT-IR etc. The ligands 1a-d can then react with the CuBr.Me2S to form Cu complexes (2a-d), {Rf=C8F17(2a), C9F19(2b), C10F21(2c) and C11F23(2d)}. These four copper complexes 2a-d can then be applied for the aerobic alcohol oxidization. Since the distribution coefficients of ligands 1a-d are different, they can be used in two different systems: 1. fluorous biphasic system (FBS) 2. thermomorphic system (temperature-dependent):
1. FBS: when the fluorine content of ligands greater than 62%, e.g. ligands 1c-d, they showed higher affinity for the fluorous solvent than for common organic solvent, and they had little or no solubility for organic solvent at low temperature. Fluorous biphase system (FBS) becomes homogeneous at elevated temperature and showed two phases at low temperature. By using FBS we could get product from organic phase and recover catalyst from fluorous phase.
2. Thermomorphic system: which contains the soluble reactants and insoluble catalyst, becomes homogeneous during the reaction when being heated and then could be readily separated by cooling the reaction mixtures. After the reaction, the centrifugal method is then used to separate the products and metal catalyst. In particular, these catalysts can be easily recovered simply by cooling to room temp.
Both systems are capable of efficiently catalyzing alcohol oxidation and the catalytic activities of the catalyst were excellent for eight times.
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