Khachatryan Lavrent, Xu Meng-Xia, Wu Ang-Jian, Pechagin Mikhail, Asatryan Rubik
Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA.
State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China.
J Anal Appl Pyrolysis. 2016 Sep;121:75-83. doi: 10.1016/j.jaap.2016.07.004. Epub 2016 Jul 9.
The experimental results on detection and identification of intermediate radicals and molecular products from gas-phase pyrolysis of cinnamyl alcohol (CnA), the simplest non-phenolic lignin model compound, over the temperature range of 400-800 °C are reported. The low temperature matrix isolation - electron paramagnetic resonance (LTMI-EPR) experiments along with the theoretical calculations, provided evidences on the generation of the intermediate carbon and oxygen centered as well as oxygen-linked, conjugated radicals. A mechanistic analysis is performed based on density functional theory to explain formation of the major products from CnA pyrolysis; cinnamaldehyde, indene, styrene, benzaldehyde, 1-propynyl benzene, and 2-propenyl benzene. The evaluated bond dissociation patterns and unimolecular decomposition pathways involve dehydrogenation, dehydration, 1,3-sigmatropic H-migration, 1,2-hydrogen shift, C-O and C-C bond cleavage processes.
报道了在400-800℃温度范围内，对最简单的非酚类木质素模型化合物肉桂醇（CnA）进行气相热解时，中间自由基和分子产物的检测与鉴定的实验结果。低温基质隔离-电子顺磁共振（LTMI-EPR）实验以及理论计算，为以碳和氧为中心以及氧连接的共轭自由基的生成提供了证据。基于密度泛函理论进行了机理分析，以解释CnA热解主要产物的形成；肉桂醛、茚、苯乙烯、苯甲醛、1-丙炔基苯和2-丙烯基苯。评估的键解离模式和单分子分解途径涉及脱氢、脱水、1,3-西格玛迁移的H-迁移、1,2-氢迁移、C-O和C-C键断裂过程。
