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'27 A1 NMR Spectra' in keywords
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1988 (1)
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1981 (1)
1Author    Stanislav Heřmánek, Jiří Fusek, Otomar Kříž, Bohuslav Čásenský, Zbynĕk ČernýRequires cookie*
 Title    Alkoxohydridoaluminates. I 27 AI NMR Characteristics of (C 4 H9) 4 N + AlH4_"(OR)"" in Benzene  
 Abstract    The 27 A1 NMR spectra of (C 4 H 9) 4 N + AlH 4 _ n (OR)"-prepared in the reaction of (C 4 H 9) 4 NA1H 4 with ROH (R -CH 3 , C 2 H 5 , /-C 3 H 7 , r-C 4 H 9 , «-C 5 H U , n-C 9 H 19 , cyclo-C 6 U n , C 6 H 5 , CH 3 OCH 2 CH 2) in benzene show — in contrast to the Li + and Na + salts — a distinct H-splitting, which has allowed to ascertain: 1) the presence of all members (n = 0—4) in solution, 2) the Al chemical shift and AI —H coupling constant of all individual classes, namely (n = 0): 101.6 ppm, quintet 174 Hz; (n = 1): 114-123 ppm, quartet 184-193 Hz; (n = 2): 103-112 ppm, triplet 197-219 Hz; (n = 3): 75-91 ppm, doublet 218-237 Hz; (n = 4): 51-73 ppm, singlet, 3) in-creased shielding in the order: CH 3 < n-R = i-R = sec-R < C 6 H U C 6 H 5 < r-C 4 H 9 . The anomalous "sagging" pattern of the curve: d 27 Al vs. number of OR groups, is interpreted on the basis of significant differences among Al and H and OR in electronegativity. 
  Reference    Z. Naturforsch. 42b, 539—545 (1987); received October 1 1986 
  Published    1987 
  Keywords    Tetrahydridoaluminates, Alkoxohydridoaluminates, Tetraalkoxoaluminates, 27 A1 NMR Spectra 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0539.pdf 
 Identifier    ZNB-1987-42b-0539 
 Volume    42 
2Author    Heinrich Nöth, Robert Rurländer, Peter WolfgardtRequires cookie*
 Title    Solutions of Lithium Tetrahydrido Aluminates in Ethers: a 'Li and 27 AI NMR Study  
 Abstract    Solutions of LiAlH4 in tetrahydrofuran (THF), glycoldimethylether (monoglyme), diglycoldimethylether (diglyme) and triglycoldimethylether (triglyme) as well as solutions of LiAlH4/THF in toluene have been investigated by 7 Li and 27 A1 NMR. It was found that <5 27 A1 is nearly independent of the solvent as is 1 J(A1H). However, the line width of the 27 A1 NMR signal shows strong solvent influences and, in addition, concentration and temperature dependence. Intermolecular hydride exchange becomes rapid in solutions of monoglyme and triglyme at room temperature. This can also be shown by the H/D exchange between LiAlH4 and L1AID4. <5 7 Li data indicate that Li is hexacoordinated in the series of glycoldimethylethers, and LiAlH4 in diglyme seems to be the system in which the AIH4 moiety is least affected by ion pair or triple ion formation. 
  Reference    (Z. Naturforsch. 36b, 31—41 [1981]; received July 28 1980) 
  Published    1981 
  Keywords    Lithium Tetrahydroaluminates, Lithium Tetradeuterioaluminates, 7 Li NMR Spectra, 27 A1 NMR Spectra 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-0031.pdf 
 Identifier    ZNB-1981-36b-0031 
 Volume    36 
3Author    St Böck, H. Nöth, P. RahmRequires cookie*
 Title    Lithium-dimethylamino-hydrido-aluminate: Lösungszustand in Diethylether, Tetrahydrofuran und Dimethyldiglykolether Lithium Dimethylamino Hydrido Aluminates: The Solution State in Diethylether, Tetrahydrofuran and Dimethyldiglycol Ether  
 Abstract    The reaction of LiAlH 4 with dimethylamine has been studied in THF, diglyme and diethyl ether solution covering the molar ratios 1:0.5 to 1:4. In all cases the stoichiometric amount of H : is evolved. With the exception of LiAl[N(CH 3) 2 ] 4 all other members of the series LiAlH 4 _"[N(CH 3) 2 ]" cannot be isolated. They are in equilibrium with one another in solution. These equilibria are independent of the solvent used. The structure of compound LiAl[N(CH 3) 2 ] 4 -2(OC 4 H 8) has been determined by X-ray diffrac-tion. The anion acts as a bidentate ligand to Li which is also bonded to the oxygen atoms of two THF molecules. 
  Reference    (Z. Naturforsch. 43b, 53—60 [1988]; eingegangen am 19. August 1987) 
  Published    1988 
  Keywords    Lithium Dimethylaminohydrido Aluminates, 27 A1 NMR Spectra, Solution State, X-Ray, 7 Li NMR Spectra 
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 TEI-XML for    default:Reihe_B/43/ZNB-1988-43b-0053.pdf 
 Identifier    ZNB-1988-43b-0053 
 Volume    43