Abstract Experimental heat capacities of three polycyclic aromatic hydrocarbons (PAHs), benzo[b]fluoranthene (CAS RN: 205-99-2), benzo[k]fluoranthene (CAS RN: 207-08-9), and indeno[1,2,3-cd]pyrene (CAS RN: 193-39-5) in the temperature range (2–300) K are reported (to our knowledge for the first time). Commercially available relaxation calorimeter was used for measurement. Performance of the apparatus was tested by measuring the heat capacity of copper and sapphire. However, PAHs are available in a form of powder and therefore cannot be directly placed on measuring platform as e.g. copper specimen; moreover, sample sublimation cannot be ruled out. Modified three-step method using powder sample or powder sample pressed into a pellet and inserted into aluminium DSC pans of different weights was tested by measurement of anthracene heat capacity, for which high quality data are available in the literature. Pellets of higher weight in a pan of higher mass yielded results in the best accordance with the literature data; this method was applied also for measurement of benzoic acid heat capacity. Finally, datasets on heat capacity of benzo[b]fluoranthene, benzo[k]fluoranthene, and indeno[1,2,3-cd]pyrene were recorded, smoothed and standard thermodynamic functions in the temperature range (0–300) K were calculated; standard entropy in crystalline state at 298.15 K is 270.1 ± 5.4 J·K−1·mol−1 for benzo[b]fluoranthene, 263.5 ± 5.3 J·K−1·mol−1 for benzo[k]fluoranthene, and 272.8 ± 5.4 J·K−1·mol−1 for indeno[1,2,3-cd]pyrene.

中文翻译：

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通过弛豫技术测量低温热容量：苯并[b]荧蒽、苯并[k]荧蒽和茚并[1,2,3-cd]芘的量热仪性能测试和热容量

摘要 三种多环芳烃 (PAH)、苯并 [b] 荧蒽 (CAS RN: 205-99-2)、苯并 [k] 荧蒽 (CAS RN: 207-08-9) 和茚并 [1, 2,3-cd]芘（CAS RN：193-39-5）在 (2-300) K 温度范围内被报道（据我们所知是第一次）。使用市售的弛豫量热计进行测量。通过测量铜和蓝宝石的热容量来测试设备的性能。然而，多环芳烃以粉末形式存在，因此不能直接放置在测量平台上，例如铜样品；此外，不能排除样品升华。改进后的三步法使用粉末样品或压成颗粒的粉末样品插入不同重量的铝制 DSC 盘中，通过测量蒽热容进行测试，在文献中可以获得高质量的数据。与文献数据一致，在较高质量的盘中较高质量的颗粒产生的结果最好；该方法也适用于苯甲酸热容的测量。最后，记录了苯并[b]荧蒽、苯并[k]荧蒽和茚并[1,2,3-cd]芘的热容数据集，在温度范围（0-300）K内进行了平滑和标准热力学函数的记录。计算；298.15 K 结晶态的标准熵对于苯并 [b] 荧蒽为 270.1 ± 5.4 J·K-1·mol-1，对苯并 [k] 荧蒽为 263.5 ± 5.3 J·K-1·mol-1，以及 272.8 ± 5.4 J·K-1·mol-1 茚并[1,2,3-cd]芘。该方法也适用于苯甲酸热容的测量。最后，记录了苯并[b]荧蒽、苯并[k]荧蒽和茚并[1,2,3-cd]芘的热容数据集，在温度范围（0-300）K内进行了平滑和标准热力学函数的记录。计算；298.15 K 结晶态的标准熵对于苯并 [b] 荧蒽为 270.1 ± 5.4 J·K-1·mol-1，对苯并 [k] 荧蒽为 263.5 ± 5.3 J·K-1·mol-1，以及 272.8 ± 5.4 J·K-1·mol-1 茚并[1,2,3-cd]芘。该方法也适用于苯甲酸热容的测量。最后，记录了苯并[b]荧蒽、苯并[k]荧蒽和茚并[1,2,3-cd]芘的热容数据集，在温度范围（0-300）K内进行了平滑和标准热力学函数的记录。计算；298.15 K 结晶态的标准熵对于苯并 [b] 荧蒽为 270.1 ± 5.4 J·K-1·mol-1，对苯并 [k] 荧蒽为 263.5 ± 5.3 J·K-1·mol-1，以及 272.8 ± 5.4 J·K-1·mol-1 茚并[1,2,3-cd]芘。