e.g. Filippa Pettersson or Cancer Res. 75(6) , 1102-12, (2015) or 10.1002/anie.201600521
… hindered lithium amides and their diethyl etherates: crystal and molecular structures of [Li {N (SiMe3) 2}(OEt2)] 2 and tetrakis (2, 2, 6, 6-tetramethylpiperidinatolithium)
MF Lappert, MJ Slade, A Singh, JL Atwood…
Index: Lappert, Michael F.; Slade, Martin J.; Singh, Anirudh; Atwood, Jerry L.; Rogers, Robin D.; Shakir, Riz Journal of the American Chemical Society, 1983 , vol. 105, # 2 p. 302 - 304
Figure 1. Molecular structure of (Li [N (SiMe,),](OEtz)) z, 1, with the atoms represented by their 50% probability ellipsoids for thermal motion. The dimer resides about a crystallographic 222 site: one 2-fold axis contains the lithium and oxygen atoms, one the nitrogen atoms, and the third is perpendicular to the LizNz plane.