Co-salen配合物催化氧化二聚体木素模型物的反应机理

Reaction mechanism of Co-salen complex catalyzed oxidation of dimeric lignin model compound

为研究Co-salen配合物催化漂白纸浆机理,合成了β—O—4愈创木基型二聚体木素模型物.以木素模型物为反应底物,利用傅里叶变换红外光谱(FT-IR)、碳-13核磁共振(13C-NMR)和气相色谱-质谱(GC-MS),分析了木素模型物在Co-salen催化氧化中的官能团变化和微量降解产物.根据木素模型物降解产物与结构变化,得出了β—O—4愈创木基型二聚体木素模型物的降解反应机理.Co-salen配合物催化反应系统产生的O2·-、HOO-、HO·作用于木素模型物,造成β—O—4联接断裂,甲氧基脱甲基,甲氧基含量减少,苯环开环,产生了醛、酚、烯等降解产物.

In order to investigate the Co-salen catalytic bleaching mechanism of pulp,the dimeric guaiacyl lignin model compound with β—O—4 linkage was synthesized.The degradation products and functional groups in Co-salen catalytic oxidation were analysed by GC-MS,FT-IR and 13C-NMR,respectively.The degradation mechanism of lignin model compound was elucidated based on the degradation products and structural changes.Attacks of peroxy anionic radical,hydroperoxy ion and hydroxy radical in Co-salen catalytic system made the β—O—4 linkage broke,ary ring open and methoxy reduced,yielding aldehyde,phenol and alkene.