title: Trivinylphosphine and trivinylphosphine chalcogenides: stereochemical trends of ³¹P-¹H spin-spin coupling constants.
abstract: A combined theoretical and experimental study of the stereochemical behavior of (31)P-(1)H spin-spin coupling constants has been performed in the series of trivinylphosphine and related trivinylphosphine oxide, sulfide and selenide. Theoretical energy-based conformational analysis of the title compounds performed at the MP2/6-311G** level reveals that each of the four compounds of this series exists in the equilibrium mixture of five true-minimum conformers, namely s-cis-s-cis-s-cis, s-cis-s-cis-gauche, syn-s-cis-gauche-gauche, anti-s-cis-gauche-gauche and gauche-gauche-gauche, which were taken into account in the conformational averaging of (31)P-(1)H spin-spin couplings calculated at the second-order polarization propagator approach/aug-cc-pVTZ-J level of theory. All (31)P-(1)H spin-spin coupling constants involving phosphorus and either of the vinyl protons are found to demonstrate a marked stereochemical dependences with respect to the geometry of the coupling pathway and internal rotation of the vinyl group around the P-C bond which is of major importance in the stereochemical studies of the unsaturated phosphines and phosphine chalcogenides.
authors.affiliation: A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Favorsky St. 1, 664033 Irkutsk, Russia.
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Fedorov
authors.forename: Leonid B
authors.initials: LB
authors.lastname: Krivdin
authors.forename: Yury Yu
authors.initials: YY
authors.lastname: Rusakov
authors.forename: Nataliya A
authors.initials: NA
authors.lastname: Chernysheva
authors.forename: Valentina L
authors.initials: VL
authors.lastname: Mikhailenko
mesh_terms: D018011:Chalcogens / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010759:Phosphorus Isotopes; D011522:Protons; D013237:Stereoisomerism; D014753:Vinyl Compounds / Q000737:chemistry*
chemical_list: D018011:Chalcogens; D010759:Phosphorus Isotopes; D011522:Protons; D014753:Vinyl Compounds