【作者】 王三跃；

【导师】 曾凡桂；

【作者基本信息】 太原理工大学 ， 采矿工程， 2004， 硕士

【摘要】 以分子力学、分子动力学及量子化学为基础的计算机分子模拟，从三维立体的角度建立和模拟煤大分子结构，将深化对煤大分子结构特征的认识，定量了解煤大分子结构特征与煤的各种性质的关系，使煤的结构化学研究进入一新的高度。 本文运用煤结构的傅立叶红外光谱（FTIR）和固体核磁共振碳谱(¹³C NMR)测试方法所得的结果，经过谱图分峰、分析，计算出若干表征煤大分子结构参数，并综合前人的经验和共识，利用计算机分子绘图软件系统构建了表征两种褐煤（霍林河原煤和义马原煤）的化学结构模型（Wiser model），在Cerius² 4.6／IR模块中计算了分子振动红外光谱，同时结合碳谱所计算的分子结构参数拟合、修正了该结构模型，得到了能表征这两种煤样的分子结构模型，作为用分子动力学模拟和量子化学计算的初始结构模型。用分子力场和分子动力学模拟方法得出最优构型 太原理工大学硕士研究生学位论文及在此构型下的势能、键合作用和非键合作用能等能量参数，并进行了对比，发现在煤的大分子结构中起主要作用的是非键合作用的范德华和氢键作用能。而且氢键随大分子结构的数目的增加，其作用明显加强，长程作用更长的库仑力变化不明显。 对上述分子力场优化后的分子模型，采用Cerius“材料模拟软件ZINDO半经验量子力学方法，计算和分析了模型分子的静态几何构型、原子净电荷分布、键长、最高被占据轨道（HOMO）和最低未占据轨道（LUMO）等电子结构性质，研究了激发态的相关性质。从键长的分析中得出含氧键中以碳基中的碳氧双键最为稳定，醚键和苯甲氧基中与烷基链相连的碳氧键最为不稳定;从原子上的净电荷分布来看，边缘C原子易于发生氧化反应;对最高被占据轨道（HOMO）和最低未占据轨道（LUMO）分析知道处在单双键交替的位置上的原子，没有处于共扼体系的芳环上的C原子稳定，这可以用来对于催化剂在煤的加氢液化中所起的作用做出理论解释和预测发生反应的位置。还分析和预测了模型分子的紫外/可见光谱（UV乃西s），与实际相符。更多还原

【Abstract】 The application of computer molecular simulation techniques, which base on molecular mechanics, molecular dynamics and quantum chemistry, will more distinctly the coal macromolecular structure and quantify the structure parameters along with their reactivity from the view of modeling and simulating the coal three-dimensional structure.In this thesis, two chemical structural models were constructed based on several structure parameters derived from FTIR and 13C NMR data, which were processed by curve-fitting and curve-resolved. Modified models were obtained by simulation oftheir molecular vibration spectra using Cerius 4.6/IR module andthe structural parameters from 13C NMR. Potential energy, bondenergy and non-bond energy of the minimum-energy conformations of coal macromolecules were calculated by molecular mechanics calculation and molecular dynamics simulation. These results demonstrate the importance of hydrogen bonding and van der Waals (vdW) interactions in the formation and stabilization of coal macromolecular structure, and a strongest tendency of hydrogen bonding interactions to increase with the coal molecules but the Coulomb’s force.ZINDO, a semi-empirical method of quantum chemistry implemented in programs Cerius2, was used to calculate and analyze the static conformation of models, formal charge of atoms, the bond length, HOMO and LUMO after running a preliminary minimization and other electronic properties also were studied. By analyzing bond length, all bonds including O, C=O in carbonyl group is the best stable, and R-O-R’, C-O- Ar and C-O-R are the weakest bonds type. Fringe Cs tend to be oxygenized, which can be concluded from their atomic formal charge distributions. By analyzing HOMO and LUMO of all atoms, we find those carbon atoms that are located in where single bonds and double bondsalternate are not stable like those atoms located in conjuge aromatic systems, which can be used to predict the reaction locations of hydrogenation liquefaction and translate the role of catalysts during the processing in theory. Molecular models’ UV/Vis also are calculated and analyzed in detail and the results sort well with the practice.更多还原