title: High-performance liquid chromatography enantioseparation of atropisomeric 4,4'-bipyridines on polysaccharide-type chiral stationary phases: Impact of substituents and electronic properties.
abstract: The high performance liquid chromatography (HPLC) enantioseparation of eleven atropisomeric 4,4'-bipyridines was performed in the normal and polar organic phase mode using three cellulose-based chiral stationary phases (CSPs), namely Lux Cellulose-1, Lux Cellulose-2, Lux Cellulose-4, and two amylose-based CSPs, Chiralpak AD-H and Lux Amylose-2. n-Hexane/2-propanol mixtures and pure ethanol were employed as mobile phases. The combined use of Chiralpak AD-H and Lux Cellulose-2 allowed to enantioseparate all the considered bipyridines. Ten bipyridines were enantioseparated at the multimilligram level allowing the elution sequence determination of the enantiomers as well as their future use for the preparation of homochiral metal organic frameworks (MOFs). Moreover, the performance of the CSPs regarding the same bipyridine was different and dependent on the backbone as well as on the side chain of the polymer. The impact of substitution pattern, shape and electronic properties of the molecules on the separation behavior was investigated through the evaluation of retention factors (k), separation factors (α), resolution (R(s)) and molecular properties determined using density functional theory (DFT) calculations. In this regard, the substituents at the 3,3',5,5' positions of the 4,4'-bipyridyl rings exhibited a pivotal role on the enantioseparation.
authors: Istituto di Chimica Biomolecolare ICB CNR - UOS di Sassari, Traversa La Crucca 3, Regione Baldinca, I-07100 Li Punti, Sassari, Italy. Electronic address: p.peluso@icb.cnr.it.
authors: Paola
authors: P
authors: Peluso
authors: Equipe Synthèse Organométallique et Réactivité (SOR), Laboratoire SRSMC, UMR CNRS-UHP 7565, Université de Lorraine, BP 70239, Bd des Aiguillettes, 54506 Vandoeuvre-les-Nancy, France. Electronic address: victor.mamane@univ-lorraine.fr.
authors: Victor
authors: V
authors: Mamane
authors: Cristallographie, Résonance Magnétique et Modélisations (CRM(2)), UMR CNRS-UHP 7036, Université de Lorraine, BP 70239, Bd des Aiguillettes, 54506 Vandoeuvre-les-Nancy, France.
authors: Emmanuel
authors: E
authors: Aubert
authors: Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari di Venezia, Dorsoduro 2137, I-30123 Venezia, Italy.
authors: Sergio
authors: S
authors: Cossu
mesh_terms: D000688:Amylose / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation* / Q000379:methods*; D008958:Models, Molecular; D008968:Molecular Conformation; D011725:Pyridines / Q000737:chemistry* / Q000302:isolation & purification*; D013237:Stereoisomerism
chemical_list: D011725:Pyridines; D002482:Cellulose; D000688:Amylose; C034306:4,4'-bipyridyl