Rings and Clusters Containing Polyimido and Imido/Oxo Anions of Group 13–15 Elements

Abstract

The dilithio boraamidinates {Li₂[RB(N^tBu)₂]}_x (R = Me, ⁿBu) are obtained by the reaction of B[N(H)^tBu]₃ with 3 equivalents of LiR. The X-ray structures of the dimer (R = ⁿBu) and trimer (R = Me) consist of distorted Li₄N₄ cubes or Li₆N₆ hexagonal prisms capped by two or three BR groups, respectively. The lithiation of the dimers {M[N(H)^tBu]₃}₂ (M = Al, Ga) with LiR (R = ^tBu, Me) gives rise to complexes of the type {Li[Al(N^tBu)(NH^tBu)₂]}₂(LiR) [R = ^tBu, N(H)^tBu] in which monomeric Li^tBu or LiN(H)^tBu units are trapped by the dilithiated M₂N₆ template. The centrosymmetric dimer {THF Li₃[Si(NⁱPr)₃(NHⁱPr)]}₂, formed by trilithiation of Si[N(H)ⁱPr]₄ with LiⁿBu, forms a bicapped hexagonal prism. The tetraazasilicate (Et₂O-Li)₄[Si(Nnaph)₄] is prepared by the reaction of SiCl₄ with 4 equiv. of Li₂(Nnaph). Treatment of OP[N(H)^tBu]₃ with an excess of LiⁿBu yields the dilithiated derivative {(THF)Li₂[OP(N^tBu)₂(NH^tBu)]}₂ with a box-shaped structure.

Keywords::

• Polyimido anions
• Group 13–15 elements
• lithium
• rings
• clusters