Chiral separation of novel diazenes on a polysaccharide‐based stationary phase in the reversed‐phase mode. Issue 7 (17th March 2017)

• Record Type: Journal Article
• Authors: Vojtylová, Terézia; Hamplová, Věra; Galewski, Zbigniew; Korbecka, Izabela; Sýkora, David
• Is Part Of: Journal of separation science. Volume 40:Issue 7(2017)
• Page Start: 1465
• Page End: 1469
• Publication Date: 2017-03-17
• Subjects: azobenzene -- chiral separation -- high‐performance liquid chromatography -- liquid‐crystalline materials -- photo‐induced isomerization; Separation (Technology) -- Periodicals; Chromatographic analysis -- Periodicals; 543.089
• DOI: 10.1002/jssc.201601386
• Languages: English
• ISSNs: 1615-9306

Abstract

Abstract : Chiral high‐performance liquid chromatography separation of two recently synthesized liquid crystalline materialsC1 andC2 was studied in the reversed‐phase mode. Both materials have an azo‐moiety and one chiral center in their molecular structures. They were available in racemic and pure S forms. For the enantiomeric separations, a Chiralpak AY‐RH stationary phase based on amylose tris(5‐chloro‐2‐methylphenylcarbamate) coated on 5 μm silica was used. The compounds were analyzed in both of their possible forms, the more thermodynamically stable E form and the labile Z form. The conditions and time scale of the UV‐induced E to Z transition were briefly evaluated. Under the optimized conditions, we were able to baseline separate S and R enantiomers of both of the studied materials not only in their E forms, but also in their Z forms. In comparison to the separation in the normal‐phase mode, which we have reported recently, the resolution in the reversed‐phase mode is significantly better. Interestingly, peak reversal was noticed for the S and R enantiomers when the separation was carried out with E versus Z forms of both compounds.