The Photochemical and Thermal Decomposition of Azidoacetylene in the Gas Phase, Solid Matrix, and Solutions
The Photochemical and Thermal Decomposition of Azidoacetylene in the Gas Phase, Solid Matrix, and Solutions
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叠氮乙炔在气相、固体基质和溶液中的光化学和热分解
DOI：
10.1002/ejoc.201402153
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发表时间：
2014-07-01
影响因子：
2.8
通讯作者：
Banert, Klaus
中科院分区：
文献类型：
--
作者：
Zeng, Xiaoqing;Beckers, Helmut;Banert, Klaus
研究了 1-叠氮炔的极易爆炸且不稳定的母体化合物 HCCN3（叠氮乙炔）在气相、固体氩基质和溶液中的分解。在气相中，该叠氮化物在室温下快速分解，在 0.8 mbar 的初始压力 (p0) 下半衰期 (t1/2) 为 20 分钟。在 t1/2 为 3 分钟的 O2 气氛中，衰变 (p0 = 1.0 mbar) 显着增加，其中 HC(O)CN 被确定为氰基卡宾中间体 HCCN 的捕获产物。在溶液中叠氮化物分解过程中也发现了溶剂分子（CH2Cl2 和 CHCl3）捕获该卡宾的产物，而与溴溶液形成二溴乙腈的反应被解释为通过炔本身的亲核攻击而发生。通过红外光谱和 HCCN 与异构环 C(H)CN（亚氮丙啶）和 HCNC 在 16 K 下选择性照射的相互光互转化，证实了分别通过气相和固体氩基质中叠氮化物的快速真空热解和光解（255 nm）中间形成了三线态 HCCN。
Decomposition of the extremely explosive and unstable parent compound of 1-azidoalkynes, HCCN3 (azidoacetylene), was studied in the gas phase, solid argon matrix, and solutions. In the gas phase, this azide decomposes quickly at room temperature with a half-life time (t1/2) of 20 min at an initial pressure (p0) of 0.8 mbar. The decay (p0 = 1.0 mbar) is significantly increased in an atmosphere of O2 with t1/2 of 3 min, in which HC(O)CN was identified as the trapping product of the cyanocarbene intermediate HCCN. Trapping products of this carbene by solvent molecules (CH2Cl2 and CHCl3) were also found during decomposition of the azide in solution, whereas the reaction with a solution of bromine to form dibromoacetonitrile is interpreted as taking place by nucleophilic attack of the alkyne itself. The intermediary formation of triplet HCCN by flash vacuum pyrolysis and photolysis (255 nm) of the azide in the gas phase and in solid argon matrices, respectively, was confirmed by IR spectroscopy and mutual photo-interconversion of HCCN with isomeric cyclo-C(H)CN (azirinylidene) and HCNC by selective irradiations at 16 K.