The extract and residue were acquired by CS₂–NMP (1:1, v/v) ultrasonic extraction of Malan No. 8 coking coal. The chemical structure models were constructed based on elemental and structural analyses of ¹³C NMR, Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS) using ¹³C chemical shift calculations. The formula of the extract model is C₁₇₈H₁₅₄N₂O₅S at a molecular weight of 2435.2, and the formula of the residue is C₁₈₁H₁₄₉N₃O₅S at a molecular weight of 2478.2. The elemental compositions and aromaticity values of the constructed model match well with those determined by the ultimate analysis and ¹³C NMR. The energy-minimum conformations of the extract and residue were determined through molecular mechanics (MM) and molecular dynamics (MD) methods. The optimized three-dimensional (3D) structural models were enclosed into the periodic boundary conditions (PBC) in an amorphous cell to perform density calculation. The simulated density values of the extract (1.37 g/cm³) and residue (1.40 g/cm³) were slightly lower than the true relative density (1.39 and 1.43 g/cm³, respectively) because the singular model construction does not consider the presence of small molecules, moisture, and minerals. Moreover, the X-ray diffraction (XRD) spectra were simulated at the determined density values to further validate the molecular model. Good agreement between the analytical data and the structure model was obtained. In addition, intermolecular interactions were investigated. The interactions are dominated mainly by E_B (bond length torsion energy) and secondarily by E_van (van der Waals energy), the former making the rings between the aromatic rings, aliphatic rings, and side chains stacked, and the aromatic layers tended to be parallel by π–π interaction. These findings revealed the structural features of the coking coal and were potentially useful to investigate the coal coking mechanism and beneficial for improving its utilization efficiency.

中文翻译：

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利用固态¹³ C NMR，FTIR，XPS，XRD和CAMD技术表征马兰烟煤CS ₂ -NMP提取物和残留物的分子结构特征

提取物和残留物通过CS ₂ –NMP（1：1，v / v）超声提取马兰8号炼焦煤。使用¹³ C化学位移计算，基于¹³ C NMR，傅立叶变换红外（FTIR）和X射线光电子能谱（XPS）的元素和结构分析，构建化学结构模型。提取物模型的分子式为C ₁₇₈ H ₁₅₄ N ₂ O ₅ S，分子量为2435.2，残基的分子式为C ₁₈₁ H ₁₄₉ N ₃ O _5。S的分子量为2478.2。所构建模型的元素组成和芳香度值与最终分析和¹³ C NMR所确定的元素组成和芳香度值非常匹配。通过分子力学（MM）和分子动力学（MD）方法确定提取物和残留物的最低能量构象。将优化的三维（3D）结构模型封装到非晶单元中的周期性边界条件（PBC）中，以执行密度计算。提取物（1.37 g / cm ³）和残留物（1.40 g / cm ³）的模拟密度值略低于真实相对密度（1.39和1.43 g / cm ^3）），因为奇异模型构造未考虑小分子，水分和矿物质的存在。此外，在确定的密度值下模拟X射线衍射（XRD）光谱，以进一步验证分子模型。分析数据与结构模型之间取得了良好的一致性。另外，研究了分子间的相互作用。相互作用主要由E _B（键长扭转能）决定，其次由E _van决定。（范德华力），前者使芳环，脂族环和侧链之间的环堆叠，而芳族层则倾向于通过π-π相互作用而平行。这些发现揭示了炼焦煤的结构特征，对于研究炼焦煤的机理和提高其利用率具有潜在的实用价值。