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基于理论线性溶解能相关的思想,对117个一元醇(训练集含85个,外推集含32个)分别用HyperChem 7.5中的CNDO、INDO、MINDO3、MNDO、MNDOd、AM1和PM3量子化学方法进行结构优化和振动分析,计算了分子平均极化率α、偶极矩μ、最正氢原子电荷qH+、最负原子电荷q-、前线轨道能级ELUMO和EHOMO、经零点能校正的总能Etotal和标准生成热Hf等参数,将所得训练集参数对lgKow实验值进行了逐步回归建模和预测。研究表明,各方法计算的同一参数大多存在显著差异, PM3对结构适应性和优化效率最好,其参数所建方程是最优模型,可靠性最高,稳定性和预测精度好,应用于外推集化合物以及含饱和碳环、双键或苯环的非同系物也能取得良好结果。该模型可以揭示,一元醇主要作为质子受体以羟基氧原子接受溶剂质子实现向有机相转移,除极化作用外溶质溶剂的相互作用是以静电为主而价键较弱的分子间氢键。
Based on the theory of theoretical linear solubilization energy, 117 monohydric alcohols (training set containing 85 and extrapolating set containing 32) were respectively identified by CNDO, INDO, MINDO3, MNDO, MNDOd, AM1 and PM3 in HyperChem 7.5 Structural optimization and vibration analysis were carried out. The average molecular polarizability α, the dipole moment μ, the most positive hydrogen atom charge qH +, the most negative atomic charge q-, the frontier orbital energy levels ELUMO and EHOMO were calculated. Etotal and standard heat of formation Hf and other parameters, the training set parameters obtained lgKow experimental value of a stepwise regression modeling and prediction. The results show that most of the same parameters calculated by each method have significant differences. PM3 has the best structural adaptability and optimization efficiency, and the equation constructed by the parameters is the best model with the highest reliability, stability and prediction accuracy, and is applied to extrapolation Set compounds and non-homologs with saturated carbocycles, double bonds or benzene rings give good results. The model reveals that monohydric alcohols are mainly proton acceptors that accept hydroxyl protons as solvent protons for the transfer to the organic phase. In addition to polarization, the interaction of the solute solvents is based on electrostatic interactions and weakly bonded intermolecular hydrogen bonds .