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本文报道了用电子顺磁共振法考察γ-Al_2O_3和经HF交换的F-γ-Al_2O_3分别与强吸电子剂(四氰乙烯)、强氧化剂(醌类)和具有电子授受二性物(稠环芳烃)进行电子转移反应的结果。认为在γ-Al_2O_3表面上存在着具有较强电子受体特性中心,稠环芳烃吸附于其上并把π电子转移给它,生成正离子自由基,其强度为10~(15)自旋数/克量级;同时也存在着具有强电子授体特性中心,四氰乙烯和醌氢醌吸附于其上并夺得其电子,生成负离子自由基,其强度为10~(17)自旋数/克量级。经过氟交换后的F-γ-Al_2O_3的吸电子的能力增加两个数量级,而给电子的能力则相应地降低一个数量级。
In this paper, we report the electronic paramagnetic resonance method for the determination of γ-Al 2 O 3 and HF-exchanged F-γ-Al 2 O 3 with strong electron withdrawing agents (tetracyanoethylene), strong oxidants (quinones) Aromatics) as a result of electron transfer reaction. It is believed that there is a strong center of electron acceptor on the surface of γ-Al 2 O 3. The condensed ring aromatic is adsorbed on it and the π electron is transferred to it to generate a positive ion radical with a intensity of 10-15 spins / Gram order; there are also centers with strong electron donor properties, tetracyanoethylene and quinone hydroquinone adsorbed thereon and won their electrons, generating anion free radicals, the intensity of 10 ~ (17) spin number / Gram level. The fluorine-exchanged F-γ-Al 2 O 3 electron-withdrawing ability increases by two orders of magnitude and the electron-donating ability decreases by an order of magnitude.