7Li-Solid-State-NMR of [Li(N,N,N',N'-Tetramethylethylenediamine)] CLO4 and [Li (N,N,N', N'-Tetramethylethylenediamine)2] Al(CH3)4

Abstract

Abstract The temperature dependent 7Li-solid-state-NMR spectra of the two compounds [Li(N,N,N',N'- tetramethylethylenediamine)]ClO4 and [Li(N,N,N\N tetramethylethylenediamine)2]Al(CH3)4 are presented. Both compounds were investigated in the temperature range 160 K ≦ T ≦ 360 K. Above room temperature, the spectra for the tetramethylaluminate show the typical line shape for a first-order quadrupolar-disturbed central transition with an axially symmetric asymmetry parameter and a slightly positive temperature dependence of the quadrupole coupling constant. The mean temperature coefficient ά = + 9 • 10-4 K -1 . The quadrupole coupling constant is in the range of 36-39 kHz. In the Temperature range 240 K ≦ T ≦ 275 K the quadrupolar splitting cannot be resolved. Below 240 K the quadrupole coupling constant is about 100 kHz. Contrarily, in the Perchlorate the quadrupole coupling constant is 75 kHz and is temperature independent. With increasing temperature the satellites lower in intensity and the central transition undergoes motional narrowing