The temperature dependence of heat capacity of polycyclic aromatic hydrocarbon, benzo[a]pyrene, was investigated in the temperature range T = 7.5–329.3 K using adiabatic calorimetry. Smoothed C_p,m^°(T) values between 0 and 329 K are presented along with values for the standard thermodynamic functions: S_m^°, [H_m^°(T) – H_m^°(0)], and [G_m^°(T) – G_m^°(0)]. Using the C_p,m^°(T) data, the standard molar third-law entropy at T = 298.15 K, S_m^°, is calculated as 279.7 ± 1.7 J·K^–1·mol^–1. The enthalpy of combustion, Δ_cH_m^°, of benzo[a]pyrene has been determined using the isothermal combustion calorimeter with a stationary bomb. These new experimental results, together with literature data, are used to calculate the standard enthalpy of formation, Δ_fH_m^°, and standard Gibbs free energy of formation, Δ_fG_m^°, giving Δ_fH_m^°(T = 298.15 K, benzo[a]pyrene, cr) = 162.4 ± 15.5 kJ·mol^–1 and Δ_fG_m^°(T = 298.15 K, benzo[a]pyrene, cr) = 347.0 ± 15.7 kJ·mol^–1. Additionally, the quantum chemistry approach was used in order to calculate the electronic structure and thermodynamic properties for benzo[a]pyrene.

中文翻译：

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苯并[a]芘：来自绝热和燃烧量热法以及密度泛函理论的标准热力学特性

使用绝热量热法在T = 7.5–329.3 K的温度范围内研究了多环芳烃苯并 [ a ] 芘的热容量的温度依赖性。0 到 329 K 之间的平滑C _p,m ^° ( T ) 值与标准热力学函数的值一起显示：S _m ^°、[ H _m ^° ( T ) – H _m ^° (0)] 和 [ G _m ^° ( T ) – G _m ^° (0)]。使用C _p,m ^°( T ) 数据，T = 298.15 K 时的标准摩尔第三定律熵，S _m ^°，计算为 279.7 ± 1.7 J·K ^–1 ·mol ^–1。苯并[ a ]芘的燃烧焓Δ _c H _m ^°已使用带有固定炸弹的等温燃烧量热计测定。这些新的实验结果与文献数据一起用于计算标准生成焓 Δ _f H _m ^°和标准吉布斯生成自由能 Δ _f G _m ^°，给出 Δ _f H_m ^° ( T = 298.15 K, 苯并[ a ]芘, cr) = 162.4 ± 15.5 kJ·mol ^–1和 Δ _f G _m ^° ( T = 298.15 K, 苯并[ a ]芘, cr) = 347.0 ± 15.7 kJ ·mol ^–1 . 此外，还使用量子化学方法计算苯并[ a ]芘的电子结构和热力学性质。