title: Enantiomeric separations of ruthenium (II) polypyridyl complexes using HPLC with cyclofructan chiral stationary phases.
abstract: The enantiomeric separation of 21 ruthenium (II) polypyridyl complexes was achieved with a novel class of cyclofructan-based chiral stationary phases (CSPs) in the polar organic mode. Aromatic derivatives on the chiral selectors proved to be essential for enantioselectivity. The R-napthylethyl carbamate functionalized cyclofructan 6 (LARIHC CF6-RN) column proved to be the most effective overall, while the dimethylphenyl carbamate cyclofructan 7 (LARIHC CF7-DMP) showed complementary selectivity. A combination of acid and base additives was necessary for optimal separations. The retention factor vs. acetonitrile/methanol ratio plot showed a U-shaped retention curve, indicating that different interactions take place at different polar organic solvent compositions. The separation results indicated that π-π interactions, steric effects, and hydrogen bonding contribute to the enantiomeric separation of ruthenium (II) polypyridyl complexes with cyclofructan chiral stationary phases in the polar organic mode.
authors.affiliation: College of Life and Health Sciences, Northeastern University, Shenyang, China; Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, TX, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Shu
authors.forename: Zachary S
authors.initials: ZS
authors.lastname: Breitbach
authors.forename: Milan K
authors.initials: MK
authors.lastname: Dissanayake
authors.forename: Sirantha
authors.initials: S
authors.lastname: Perera
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Aslan
authors.forename: Nagham
authors.initials: N
authors.lastname: Alatrash
authors.forename: Frederick M
authors.initials: FM
authors.lastname: MacDonnell
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Armstrong
mesh_terms: D002851:Chromatography, High Pressure Liquid; D056831:Coordination Complexes / Q000737:chemistry*; D005630:Fructans / Q000737:chemistry*; D015394:Molecular Structure; D011725:Pyridines / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D056831:Coordination Complexes; D005630:Fructans; D011725:Pyridines; C557358:cyclofructan 6; D012428:Ruthenium
keywords: LARIHC; chiral stationary phase; cyclofructan; enantiomeric separation; ruthenium (II) polypyridyl complexes