Photophysics and photochemistry of a lignin model molecule containing α-carbonyl guaiacyl and 4-hydroxy-3-methoxybenzyl alcohol moieties
作者:Alain Castellan、Stéphane Grelier、Larbi Kessab、Aziz Nourmamode、Yacine Hannachi
DOI:10.1039/p29960001131
日期:——
representing the two ends. They show that in non-polar and very good hydrogen donor solvents there is interaction between the excited carbonyl and the phenolic group, the chain probably being in a folded conformation. In alcoholic solvents and in HPC films, an intermolecular interaction between the carbonyl chromophore and the hydroxy group of the solvent was observed, the hexamethylene chain being in an extended
木质素模型分子(DCOOH),包含一个α-羰基愈创木脂部分和一个通过n连接的4-羟基-3-甲氧基苄醇部分正己烷链,已经合成。与代表两端的模型相比,在室温和77 K下研究了基态和激发态(快速光解)的电子吸收光谱以及稀溶液(酒精和烷烃)和羟丙基纤维素(HPC)膜中的发光性质。 。他们表明,在非极性和非常好的氢供体溶剂中,激发的羰基和酚基之间存在相互作用,该链可能处于折叠构象。在醇溶剂和HPC膜中,观察到羰基发色团和溶剂羟基之间的分子间相互作用,六亚甲基链处于延伸构象。紫外线照射在HPC薄膜中的二聚体和羰基单体,表现出相似的反应性,似乎涉及通过激发态羰基从周围介质中吸收分子间氢。发现羰基衍生物在异丙醇和四氢呋喃(THF)中的反应性与薄膜所观察到的相似。在THF中,分离并表征了羰基单体(MCOET)和四氢呋喃之间的两个异构体光加合物。在烷烃溶剂中,节食剂的紫外线辐射会导致在长波长范围内出现新的谱带