title: Structure determination and conformation analysis of symmetrical dimers.
abstract: Conformational and stereochemical analysis of six new symmetrical dimers was performed using proton-proton vicinal coupling measured from (1)H NMR and (13)C satellites of (1)H NMR signals, natural abundance (13)C-edited nuclear overhauser effect (NOE) experiments, comprehensive NOE analysis and molecular modeling. The (13)C satellite analysis and (13)C-edited NOE experiments were carried out to extract spectral information between equivalent protons. Molecular modeling was applied for estimations of three-dimensional parameters of the studied dimers, which were subsequently used to generate a set of theoretical NOE for each possible conformation. The J-coupling, (13)C-edited NOE and quantitative NOE analyses showed the predominance of gauche conformation for three dimers, whereas a mixture of gauche and anti conformations (45:55) for three other dimers was established by quantitative NOE analysis. X-ray crystallographic study confirmed the stereochemistry of one of the dimers and revealed a discrepancy in conformation stability between liquid and solid states.
authors.affiliation: Schering-Plough Research Institute, 2015 Galloping Hill Rd, Kenilworth, NJ 07033-1300, USA.
authors.forename: Alexei V
authors.initials: AV
authors.lastname: Buevich
authors.forename: Tze-Ming
authors.initials: TM
authors.lastname: Chan
authors.forename: C H
authors.initials: CH
authors.lastname: Wang
authors.forename: Andrew T
authors.initials: AT
authors.lastname: McPhail
authors.forename: A K
authors.initials: AK
authors.lastname: Ganguly
mesh_terms: D002247:Carbon Isotopes; D003198:Computer Simulation; D003461:Crystallography / Q000379:methods*; D019281:Dimerization; D006838:Hydrocarbons / Q000032:analysis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008958:Models, Molecular; D008968:Molecular Conformation; D011522:Protons
chemical_list: D002247:Carbon Isotopes; D006838:Hydrocarbons; D011522:Protons