title: The synthesis of rigid polycyclic structures for the study of diatropic or steric effects of a phenyl ring on CF bond.
abstract: Polycyclic compounds 1a-c were synthesized to study the diatropic effects of a flanking phenyl ring on nearby CH and CF bonds. (19)F NMR spectra of 1b and 1c were strongly deshielded compared with those of the ring-opened compounds 3b, 7b, and 7c. DMol3 calculations on 1a-c provided quantitative bond lengths and torsional angles to support the conclusion that the downfield shifts in the (19)F NMR spectra are mainly due to steric interactions between the CF bonds and the π clouds of the phenyl ring(s).
authors: Department of Applied Chemistry, National Chiao-Tung University , Hsinchu 30050, Taiwan ROC.
authors: Yung-Yu
authors: YY
authors: Chang
authors: I-Ting
authors: IT
authors: Ho
authors: Tse-Lok
authors: TL
authors: Ho
authors: Wen-Sheng
authors: WS
authors: Chung
mesh_terms: D018360:Crystallography, X-Ray; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D011083:Polycyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D011083:Polycyclic Compounds