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2000 (1)
1980 (1)
1Author    Heinrich NöthRequires cookie*
 Title    Lithium-tetrahydroaluminat in Ether: eine NMR-Untersuchung Lithiumtetrahydroaluminate in Ether: an NMR Study  
 Abstract    Ether solutions of LiAlH4 have been investigated by 27 Al and 7 Li magnetic resonance in the concentration range 3.75-0.0075 M. The Al-signal shows a fine structure due to Al-H coupling only at concentrations below 0.15 M. The observed chemical shift 27 Al is only slightly concentration dependent. The line width of the 27 A1 signal, which is inversely proportional to T2*, reaches a minimum value at a concentration where the best resolution of the 27 A1 quintet is observed. This, however, is not matched by the 7 Li line width whose minimum value was found at a somewhat higher concentration. The results are consistent with multiple ion formation at the higher concentrations and with an ion pair at low concentrations. 
  Reference    (Z. Naturforsch. 35b, 119—124 [1980]; eingegangen am 7. November 1979) 
  Published    1980 
  Keywords    7 Li NMR, 27 A1 NMR, Relaxation Times, Lithiumtetrahydroaluminate 
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 TEI-XML for    default:Reihe_B/35/ZNB-1980-35b-0119.pdf 
 Identifier    ZNB-1980-35b-0119 
 Volume    35 
2Author    Yasumasa Tomita, Hiroshi Ohki, Koji Yamada, Tsutomu OkudaRequires cookie*
 Title    Dynamic Behavior of Group 13 Elements in Bromocomplexes as Studied by NQR and NMR  
 Abstract    NMR, NQR, powder X-ray diffraction, DTA and AC conductivity were measured in RMBr 4 (R = Ag, Cu; M = Al, Ga) and RMiBr 7 (R = Li, Ag; M = Al, Ga). In RMBr 4 , the activation energy of Cu + diffusion was evaluated from ^Cu NMR and was in good agreement with that from S1 Br NQR. In CuAlBr 4 , the e 2 Qq/h value of 63 Cu NMR and the 77 value of 27 AI NMR changed linearly with decreasing temperature, although the e 2 Qq/h value of 27 AI NMR did not change so much. These temperature dependences are supposed to be due to Cu + diffusion and not to a variation of the lattice constants. In RMiBr 7 , the activation energy was obtained from the spin-lattice relaxation time T x of 81 Br NQR and is ascribed to a modulation of the cation diffusion. The line width of 7 Li NMR in LiAl 2 Br 7 was about 5.9 kHz in the low-temperature phase and 0.4 kHz for the high-temperature phase. The 27 A1 NMR spectrum was broadened by the quadrupole interaction and unchanged up to 400 K, suggesting that diffusion of Li + ions occurs in the high-temperature phase. 
  Reference    Z. Naturforsch. 55a, 117—123 (2000); received August 25 1999 
  Published    2000 
  Keywords    T x of 81 Br NQR, 27 A1 NMR, 7 Li NMR, 63 Cu NMR, Cation Diffusion 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0117.pdf 
 Identifier    ZNA-2000-55a-0117 
 Volume    55