Department of Chemistry, Marshall University, Huntington, West Virginia 25755, USA.
J Chem Phys. 2013 Dec 7;139(21):214303. doi: 10.1063/1.4832898.
The thermal decomposition of gas-phase butyraldehyde, CH3CH2CH2CHO, was studied in the 1300-1600 K range with a hyperthermal nozzle. Products were identified via matrix-isolation Fourier transform infrared spectroscopy and photoionization mass spectrometry in separate experiments. There are at least six major initial reactions contributing to the decomposition of butyraldehyde: a radical decomposition channel leading to propyl radical + CO + H; molecular elimination to form H2 + ethylketene; a keto-enol tautomerism followed by elimination of H2O producing 1-butyne; an intramolecular hydrogen shift and elimination producing vinyl alcohol and ethylene, a β-C-C bond scission yielding ethyl and vinoxy radicals; and a γ-C-C bond scission yielding methyl and CH2CH2CHO radicals. The first three reactions are analogous to those observed in the thermal decomposition of acetaldehyde, but the latter three reactions are made possible by the longer alkyl chain structure of butyraldehyde. The products identified following thermal decomposition of butyraldehyde are CO, HCO, CH3CH2CH2, CH3CH2CH=C=O, H2O, CH3CH2C≡CH, CH2CH2, CH2=CHOH, CH2CHO, CH3, HC≡CH, CH2CCH, CH3C≡CH, CH3CH=CH2, H2C=C=O, CH3CH2CH3, CH2=CHCHO, C4H2, C4H4, and C4H8. The first ten products listed are direct products of the six reactions listed above. The remaining products can be attributed to further decomposition reactions or bimolecular reactions in the nozzle.
气相正丁醛（CH3CH2CH2CHO）的热分解在 1300-1600 K 范围内通过超热喷嘴进行研究。在单独的实验中，通过矩阵隔离傅里叶变换红外光谱和光电离质谱鉴定了产物。至少有六个主要的初始反应有助于正丁醛的分解：导致丙基自由基+CO+H 的自由基分解通道；形成 H2+乙基乙烯酮的分子消除；酮-烯互变异构，然后消除 H2O 生成 1-丁炔；分子内氢转移和消除生成乙烯醇和乙烯，β-C-C 键断裂生成乙基和乙烯氧基自由基；以及γ-C-C 键断裂生成甲基和 CH2CH2CHO 自由基。前三个反应类似于在乙醛的热分解中观察到的反应，但后三个反应是由于正丁醛的长烷基链结构而成为可能。正丁醛热分解后鉴定的产物有 CO、HCO、CH3CH2CH2、CH3CH2CH=C=O、H2O、CH3CH2C≡CH、CH2CH2、CH2=CHOH、CH2CHO、CH3、HC≡CH、CH2CCH、CH3C≡CH、CH3CH=CH2、H2C=C=O、CH3CH2CH3、CH2=CHCHO、C4H2、C4H4 和 C4H8。列出的前十种产物是上述六种反应的直接产物。其余产物可以归因于喷嘴中的进一步分解反应或双分子反应。
