title: Molecular orientation of gel forming compounds and their effect on molecular-shape selectivity in liquid chromatography.
abstract: Double-alkylated glutamic acid and aminoadipic acid derived gel systems (G1 and G2) have been prepared and then grafted onto silica particles. Gel-forming compounds-grafted silica particles (Sil-G1 and Sil-G2) were then applied for the liquid chromatographic separation of shape-constrained isomers of polycyclic aromatic hydrocarbons (PAHs) and tocopherols as stationary phases. G1 and G2 were analyzed before and after immobilization onto silica. Elemental analysis and thermogravimentric analysis (TGA) results showed almost the same amounts of organic phases were grafted in Sil-G1 and Sil-G2 phases. However, chromatographic results showed large differences of molecular-shape selectivity between the stationary phases. Little change in the chemical structures of the gel-forming compounds can change the molecular orientation as well as drastic change in molecular recognition in liquid chromatography. Molecular orientation of the functional groups affected the interaction mechanism for the separation of shape-constrained isomers. Comparison of the shape selectivity of Sil-G1 and Sil-G2 phases with other commercial columns is also described.
authors.affiliation: Department of Applied Chemistry and Biochemistry, Faculty of Engineering, Kumamoto University, 2-39-1 Kurokami, Kumamoto, Japan.
authors.forename: Abul K
authors.initials: AK
authors.lastname: Mallik
authors.affiliation: Department of Applied Chemistry and Biochemistry, Faculty of Engineering, Kumamoto University, 2-39-1 Kurokami, Kumamoto, Japan.
authors.forename: Sudhina
authors.initials: S
authors.lastname: Guragain
authors.affiliation: Department of Applied Chemistry and Biochemistry, Faculty of Engineering, Kumamoto University, 2-39-1 Kurokami, Kumamoto, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hachisako
authors.affiliation: Department of Applied Chemistry and Chemical Engineering, University of Dhaka, Dhaka 1000, Bangladesh.
authors.forename: Mohammed Mizanur
authors.initials: MM
authors.lastname: Rahman
authors.affiliation: Department of Applied Chemistry and Biochemistry, Faculty of Engineering, Kumamoto University, 2-39-1 Kurokami, Kumamoto, Japan; Kumamoto Institute for Photo-Electro Organics (Phoenics), Kumamoto 862-0901, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Takafuji
authors.affiliation: Department of Applied Chemistry and Biochemistry, Faculty of Engineering, Kumamoto University, 2-39-1 Kurokami, Kumamoto, Japan; Kumamoto Institute for Photo-Electro Organics (Phoenics), Kumamoto 862-0901, Japan. Electronic address: ihara@kumamoto-u.ac.jp.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Ihara
mesh_terms: D000272:Adipates / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods*; D005782:Gels / Q000737:chemistry; D018698:Glutamic Acid / Q000737:chemistry; D006860:Hydrogen Bonding; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013696:Temperature; D024505:Tocopherols / Q000737:chemistry
chemical_list: D000272:Adipates; D005782:Gels; D011084:Polycyclic Aromatic Hydrocarbons; D018698:Glutamic Acid; D012822:Silicon Dioxide; C029900:adipic acid; D024505:Tocopherols
keywords: Carbonyl−π interaction; Molecular gel; Molecular-shape selectivity; Polycyclic aromatic hydrocarbons; Reversed-phase chromatography; Tocopherol