ZfN: Search Results

1	Author	Stanislav Heřmánek, Jiří Fusek, Otomar Kříž, Bohuslav Čásenský, Zbynĕk Černý	Requires 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

2	Author	Heinrich Nöth, Robert Rurländer, Peter Wolfgardt	Requires 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

3	Author	St Böck, H. Nöth, P. Rahm	Requires 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