当前位置: X-MOL 学术Org. Process Res. Dev. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Thermal Stability and Explosive Hazard Assessment of Diazo Compounds and Diazo Transfer Reagents.
Organic Process Research & Development ( IF 3.1 ) Pub Date : 2019-11-28 , DOI: 10.1021/acs.oprd.9b00422
Sebastian P Green 1, 2 , Katherine M Wheelhouse 3 , Andrew D Payne 3 , Jason P Hallett 2 , Philip W Miller 1 , James A Bull 1
Affiliation  

Despite their wide use in academia as metal-carbene precursors, diazo compounds are often avoided in industry owing to concerns over their instability, exothermic decomposition, and potential explosive behavior. The stability of sulfonyl azides and other diazo transfer reagents is relatively well understood, but there is little reliable data available for diazo compounds. This work first collates available sensitivity and thermal analysis data for diazo transfer reagents and diazo compounds to act as an accessible reference resource. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and accelerating rate calorimetry (ARC) data for the model donor/acceptor diazo compound ethyl (phenyl)diazoacetate are presented. We also present a rigorous DSC dataset with 43 other diazo compounds, enabling direct comparison to other energetic materials to provide a clear reference work to the academic and industrial chemistry communities. Interestingly, there is a wide range of onset temperatures (T onset) for this series of compounds, which varied between 75 and 160 °C. The thermal stability variation depends on the electronic effect of substituents and the amount of charge delocalization. A statistical model is demonstrated to predict the thermal stability of differently substituted phenyl diazoacetates. A maximum recommended process temperature (T D24) to avoid decomposition is estimated for selected diazo compounds. The average enthalpy of decomposition (ΔH D) for diazo compounds without other energetic functional groups is -102 kJ mol-1. Several diazo transfer reagents are analyzed using the same DSC protocol and found to have higher thermal stability, which is in general agreement with the reported values. For sulfonyl azide reagents, an average ΔH D of -201 kJ mol-1 is observed. High-quality thermal data from ARC experiments shows the initiation of decomposition for ethyl (phenyl)diazoacetate to be 60 °C, compared to that of 100 °C for the common diazo transfer reagent p-acetamidobenzenesulfonyl azide (p-ABSA). The Yoshida correlation is applied to DSC data for each diazo compound to provide an indication of both their impact sensitivity (IS) and explosivity. As a neat substance, none of the diazo compounds tested are predicted to be explosive, but many (particularly donor/acceptor diazo compounds) are predicted to be impact-sensitive. It is therefore recommended that manipulation, agitation, and other processing of neat diazo compounds are conducted with due care to avoid impacts, particularly in large quantities. The full dataset is presented to inform chemists of the nature and magnitude of hazards when using diazo compounds and diazo transfer reagents. Given the demonstrated potential for rapid heat generation and gas evolution, adequate temperature control and cautious addition of reagents that begin a reaction are strongly recommended when conducting reactions with diazo compounds.

中文翻译:


重氮化合物和重氮转移试剂的热稳定性和爆炸危险评估。



尽管重氮化合物在学术界广泛用作金属卡宾前体,但由于担心其不稳定性、放热分解和潜在的爆炸行为,在工业中通常避免使用重氮化合物。磺酰叠氮化物和其他重氮转移试剂的稳定性相对较好地了解,但重氮化合物的可靠数据很少。这项工作首先整理了重氮转移试剂和重氮化合物的可用灵敏度和热分析数据,作为可访问的参考资源。给出了模型供体/受体重氮化合物乙基(苯基)重氮乙酸酯的热重分析(TGA)、差示扫描量热法(DSC)和加速量热法(ARC)数据。我们还提供了包含 43 种其他重氮化合物的严格 DSC 数据集,可以与其他含能材料进行直接比较,为学术和工业化学界提供清晰的参考工作。有趣的是,这一系列化合物的起始温度(T onset)范围很广,在 75 至 160 °C 之间变化。热稳定性变化取决于取代基的电子效应和电荷离域量。统计模型被证明可以预测不同取代的重氮乙酸苯基酯的热稳定性。针对选定的重氮化合物,估算了避免分解的最高推荐工艺温度 (T D24)。没有其他高能官能团的重氮化合物的平均分解焓 (ΔH D) 为 -102 kJ mol-1。使用相同的 DSC 方案对几种重氮转移试剂进行了分析,发现它们具有更高的热稳定性,这与报道的值基本一致。 对于磺酰叠氮试剂,观察到平均 ΔHD 为 -201 kJ mol-1。 ARC 实验的高质量热数据表明,(苯基)重氮乙酸乙酯在 60 °C 时开始分解,而普通重氮转移试剂对乙酰氨基苯磺酰叠氮化物 (p-ABSA) 的分解起始温度为 100 °C。将吉田相关系数应用于每种重氮化合物的 DSC 数据,以指示其冲击敏感性 (IS) 和爆炸性。作为纯物质,预计所测试的重氮化合物均不会爆炸,但许多重氮化合物(特别是供体/受体重氮化合物)预计对冲击敏感。因此,建议对纯重氮化合物进行操作、搅拌和其他加工时要格外小心,以避免影响,尤其是大量时。提供完整的数据集是为了让化学家了解使用重氮化合物和重氮转移试剂时危害的性质和程度。鉴于已证明的快速发热和气体逸出的潜力,强烈建议在与重氮化合物进行反应时充分控制温度并谨慎添加引发反应的试剂。
更新日期:2020-01-01
down
wechat
bug