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首页> 外文期刊>Journal of chromatography, A: Including electrophoresis and other separation methods >Chromatographic retention behaviour of monosubstituted benzene derivatives on porous graphitic carbon and octadecyl-bonded silica studied using molecular modelling and quantitative structure-retention relationships
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Chromatographic retention behaviour of monosubstituted benzene derivatives on porous graphitic carbon and octadecyl-bonded silica studied using molecular modelling and quantitative structure-retention relationships

机译：使用分子建模和定量结构-保留关系研究了单取代苯衍生物在多孔石墨碳和十八烷基键合二氧化硅上的色谱保留行为

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摘要

The retention behaviour of a series of 28 monosubstituted benzenes, representing a diverse range of functional groups and substituent shape, were investigated using porous graphitic carbon (PGC) and octadecyl-bonded silica (ODS) stationary phases. For the majority of analytes retention on PGC was greater than on ODS, and in most cases this effect occurred at both pH 2.5 and 7.0. The main trends observed on PGC (in comparison with ODS) were: (i) similar or reduced retention of low polarity molecules such as the hydrocarbon and halogenated analytes; (ii) increased retention of conjugated analytes with extended planarity; (iii) increased retention of polar and charged species; and (iv) substantial increases in retention for selected polar and negatively charged analytes, including some ionised and unionised acid analytes. Poor retention of positively charged analytes was observed on both stationary phases. Molecular modelling studies have explored the geometry of π- π stacking interactions in retention on PGC and have highlighted the strong retention of large conjugated analytes, with extended planar conformations, which can interact with the graphite surface with cofacial geometry. Quantitative structure-retention relationships showed the importance of hydrophobic (π) and electronic factors (e.g. mean polarisability and LUMO energy) in retention on PGC, whilst retention on ODS was correlated to hydrophobicity (log. P and π).
机译：使用多孔石墨碳（PGC）和十八烷基键合二氧化硅（ODS）固定相研究了代表28种不同官能团和取代基形状的28种单取代苯的保留行为。对于大多数分析物，在PGC上的保留大于在ODS上，并且在大多数情况下，这种影响在pH 2.5和7.0时都会发生。在PGC上观察到的主要趋势（与ODS相比）是：（i）低极性分子（例如碳氢化合物和卤代分析物）的保留程度相似或降低; （ii）增加了具有扩展平面性的共轭分析物的保留; （iii）增加极性和带电物种的保留; （iv）对选定的极性和负电荷分析物（包括一些电离和联合酸分析物）的保留时间大大增加。在两个固定相上均观察到带正电荷的分析物保留不佳。分子建模研究探索了在PGC上保留时π-π堆积相互作用的几何形状，并突出显示了具有扩展平面构象的大型共轭分析物的强保留性，该构象可以与具有界面几何形状的石墨表面相互作用。定量结构-保留关系显示了疏水性（π）和电子因子（例如平均极化率和LUMO能量）在PGC上保留的重要性，而在ODS上的保留与疏水性相关（log。P和π）。

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