Automatic Selection of Mobile Phases. VII. Thin‐Layer Chromatography on Silica and Alumina of 11,12‐Disubstituted trans/cis‐11,12‐Dihydro‐6H‐dibenzo[c,h]chromen‐6‐ones

Abstract

Fifteen title compounds with four fused rings and two varying substituents were used to further specify the scope and limitation of a theoretical approach (the Snyder theory and LSChrom software) for selection of mobile phases avoiding any trial and error experiments. Based on the structure of the compounds, the theoretical treatment predicted values of strength ϵ of suitable mobile phases for TLC, namely 0.311 for silica and 0.446 for alumina. Sixteen specific mobile phases with such or close values of ϵ were arbitrarily selected from lists prepared by complex calculations. They were used to perform TLC. The data obtained showed that the retentions in all 256 measurements done were above the origin and below the solvent front. Thus, a good agreement between the theoretical and experimental data was established, thus proving a successful application of the approach. The retentions of all compounds and separation of one cis/trans pair depended on the stationary phase, ϵ, and the tuning parameters m and P′ of the mobile phases.

Keywords:

• Normal‐phase liquid chromatography
• Thin‐layer chromatography
• Silica
• Alumina
• O‐containing heterocycles
• Dibenzo[c,h]chromen
• Cis/trans isomers
• Mobile‐phase selection
• Snyder theory in LSChrom software

Acknowledgment

The authors are grateful to Prof. Lloyd Snyder for helpful comments and encouragement during the elaboration of both versions of LSChrom.