Molecular structures and NMR studies of lithium and germanium(II) complexes of a new chelating amido-imino ligand obtained by addition of nBuLi to 1,2-bis(arylimino)acenaphthene

摘要

The reaction of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-bian, 1) with 1 equiv. of nBuLi in diethyl ether or with 2 equiv. of nBuLi in bexane produces [{dpp-bian(nBu)}Li(Et2O)] (3) and [{dpp-bian(nBu)Li}nBuLi](2) (4), respectively. Complexes 3 and 4 are formed by the transfer of an nBu anion to one of the imine carbon atoms of the dpp-bian ligand. Treatment of 3 and 4 with H2O affords the C-alkylated N-protonated amino-imino compound dpp-bian(H)(nBu) (5). The reaction of 3 with GeCl2(dioxane) affords the three-coordinate germylene complex [{dpp-bian(nBu)}GeCl] (6). The molecular structures of 3-6 were determined by single-crystal X-ray structure analysis. The lack of symmetry in the alkylated bian system in 3-6 causes the non-equivalence of all protons except those of the CH3 groups of the iPr substituents.