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1997 (1)
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1Author    Zoran Marković, Stanimir Konstantinović, Ivan GutmanRequires cookie*
 Title    The Dependence of Vicinal Proton-Proton Coupling Constants of Norbomenes on Molecular Structure  
 Abstract    A modification of the Karplus equation, containing four mutually independent structural terms and five adjustable parameters, is put forward. The new structural factor, intro-duced into this modification is sin {6 1 -I-6 2)/2. The new equa-tion reproduces experimental NMR vicinal coupling con-stants of norbornenes with a standard deviation of about 0.45 Hz. 
  Reference    Z. Naturforsch. 51a, 1042—1044 (1996); received April 27 1996 
  Published    1996 
  Keywords    Norbornenes, Coupling Constants, Molecular Mechanics, Karplus Equation, NMR 
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 TEI-XML for    default:Reihe_A/51/ZNA-1996-51a-1042_n.pdf 
 Identifier    ZNA-1996-51a-1042_n 
 Volume    51 
2Author    Bernd Wrackmeyer, Berthold Distler, Max HerberholdRequires cookie*
 Title    U9Sn NM R Spectroscopy of Some Iron-Tin Compounds - First Measurements of One-Bond Coupling Constants V (119Sn57Fe), Geminal Coupling Constants 2/ ( 119 SnFe119Sn) and the Dependence of 119Sn Chemical Shifts on the Nature of the S n -F e Bond  
 Abstract    Carbonyliron tin complexes CpFe(CO)2-S n M e 3 (1), a5-(CO)4Fe(SnM e3)2 (2), cis-(CO)4Fe(SnM e2Cl)2 (3), [R2SnFe(CO)4]2 (4a, R = Me; 4b, R = Bu), {Me2Sn[Fe(CO)4]2}2Sn (5), Me2Sn[Fe(CO)4]2Sn[Fe(CO)4]2 (6) and Sn[Fe(CO)4]4 (7) were studied by ll9Sn N M R . It proved possible for the first time to observe coupling constants './(119Sn57Fe) in the range of 36 to 64 Hz. The large magnitude of geminal coupling constants 12/ (119SnFell9Sn)| (1400 to 1800 Hz) in the cyclic com pounds 4 to 6 indicates the presence of tin-tin interactions as an efficient coupling pathway. Extreme deshielding o f 119Sn nuclei in the complexes 6 (<5u9Sn + 953) and 7 (<5119Sn + 1532) is associated with three-centre FeSnFe bonds in these compounds. 
  Reference    Z. Naturforsch. 47b, 1749—1753 (1992); received July 28 1992 
  Published    1992 
  Keywords    Carbonyliron-Tin Complexes, 119Sn N M R, Coupling Constants 
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 TEI-XML for    default:Reihe_B/47/ZNB-1992-47b-1749.pdf 
 Identifier    ZNB-1992-47b-1749 
 Volume    47 
3Author    Max Herberhold, Volker Tröbs, Hong Zhou, Bernd WrackmeyerRequires cookie*
 Title    Reactivity and NMR Spectroscopic Properties of Tri(terf-butyl)plumbyl-amine  
 Abstract    Tri(rm-butyl)plumbyl-amine 1 was prepared and studied by one-(ID) and two-dimensional (2D) 'H, i3C, 5N and 207Pb NMR which allowed determination of the coupling signs /(Pb,13C) (> 0), 2y(207P b,'3C) (> 0), '7(207Pb,15N) (> 0; reduced coupling constant 1 A^(207Pb,I5N) < 0) and 27(207Pb-N-'H) (< 0). Transamination of 1 with aniline and pyrazole afforded the corresponding aniline (2) and pyrazole derivatives (3), respectively. N-Lithiation of 1, followed by treatment with Me3SiCl gave the tri(rm-butyl)plumbyl-trimethylsilyl-amine 5. The multinuclear magnetic resonance data of 2, 3 and 5 are presented. Trimethylplumbyl-phenyl-amine and trimethylplumbyl-ter/-butyl(dimethyl)silyl-amine were prepared and their NMR data were measured for comparison. 
  Reference    Z. Naturforsch. 52b, 1181—1184 (1997); received July 14 1997 
  Published    1997 
  Keywords    Lead, Organolead-nitrogen Compounds, NMR Spectra, Coupling Constants 
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 TEI-XML for    default:Reihe_B/52/ZNB-1997-52b-1181.pdf 
 Identifier    ZNB-1997-52b-1181 
 Volume    52 
4Author    Willy GomblerRequires cookie*
 Title    Se-und 18 C-NMR-Daten von Verbindungen mit C=S-und C—Se-Doppelbindung NMR Spectroscopic Studies on Chalcogen Compounds, III 77 Se and 13 C NMR Data of Compounds Containing C=S and C=Se Double Bonds  
 Abstract    77 Se and 13 C chemical shifts of compounds of type E = C = E' (E, E' = O, S, Se), Se = CF 2 , Se=C(NH2)2, Se = C(J-Bu)2 and l,l,3,3-tetramethyl-2-indanselon are reported. The shielding of both nuclei in the C = Se entity depends strongly on the lowest electron excitation energy. 77 Se-13 C spin-spin coupling constants for the C = Se double bond are presented for the first time. The values show a strong dependence on the s-character of the carbon atom. This indicates an important Fermi contact contribution. Furthermore the influence of halogens, CF3S and CF3SS groups on the 13 C chemical shift in thiocarbonyl compounds of the type S = C(Y)SCF 3 (Y= F, Cl, Br) and S = C(SSCF 3) 2 is described. 
  Reference    Z. Naturforsch. 36b, 1561—1565 (1981); eingegangen am 27. Juli 1981 
  Published    1981 
  Keywords    77 Se NMR Spectra, 13 C NMR Spectra, Coupling Constants, Thiocarbonyl Compounds, Selenocarbonyl Compounds 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-1561.pdf 
 Identifier    ZNB-1981-36b-1561 
 Volume    36