苯酚过氧化氢羟化过程中Dawson结构钼钒磷杂多化合物的ESR谱研究  

Studies on the ESR Spectra of Dawson-Molybdovanadophosphonic Compound in the Process of Phenol Hydroxylation

作　　者：郑莹光[1] 于剑锋[2] 董凤霞[3] 杨宇[3] 吴通好[3] 孙家锺 

机构地区：[1]吉林大学分析测试中心,长春130023 [2]理论化学研究所,长春130023 [3]吉林大学分析测试中心化学系,长春130023

出　　处：《高等学校化学学报》1997年第3期434-438,共5页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金

摘　　要：研究了苯酚过氧化氢羟化过程中Dawson结构杂多化合物的ESR谱，通过对比不同反应时间后催化剂的波谱参数，分析了反应过程中V4+→V5+的变化情况．研究结果表明，在反应初期，催化剂仅存在少量V4+，在反应时间达到2h时V4+的含量迅速增多，并出现了V（Ⅰ）及V（Ⅱ）两种波谱参数相异的四价钒，其中V(Ⅰ)对应着V＝O键上的V4+，而V（Ⅱ）则对应着加氧中间物种，反应过程中V(Ⅱ)的含量迅速增多．ESR spectra of molybdovanadophosphonic compound with Dawson structure in the process of phenol hydroxylation with H2O2 were studied. Contrasting their ESR parameters at different reaction time, the change of V4+V5+ in the system was analyzed. The results indicated that in the initial stage, a few V4+ were produced in the process of the catalyst synthesized. After two hours, the amount of V4+ increased quickly and two kinds of signals of V4+, V(Ⅰ ) and V(Ⅱ ) appeared- The ESR parameters of V(Ⅰ) were the same as ones at the initial stage, but the signals of V (Ⅰ ) were newly appeared. The increasing amount of V(Ⅱ ) is higher than that of V(Ⅰ ). We had calcuIated the de1ocalized extent of unpaired electrons by the method of Abragam Pryce and assigned that two kinds of V4+, V (Ⅰ ) and V(Ⅱ ) are all the active centre of the reaction.

关 键 词：DAWSON 杂多化合物 苯酚羟化 ESR 钼钒磷 催化剂 

分 类 号：O643.36[理学—物理化学]