Rings and clusters containing polyimido and imido/oxo anions of group 13-15 elements

The dilithio boraamidinates {Li-2[RB((NBu)-Bu-t)(2)]}(x) (R = Me, Bu-n) are obtained by the reaction of B[N(H)Bu-1](3) with 3 equivalents of LiR. The X-ray structures of the dimer (R = Bu-n) and trimer (R = Me) consist of dis torted Li4N4 cubes or Li6N6 hexagonal prisms capped by two or three BR grou ps, respectively, The lithiation of the dimers {M[N(H)Bu-t](3)}(2) (M = Al, Ga) with LiR (R = Bu-t, Me) gives rise to complexes of the type {Li[Al((NB u)-Bu-t)((NHBu)-Bu-t)(2)]}(2)(LiR) [R = Bu-t, N(H)Bu-t] in which monomeric (LiBu)-Bu-t or LiN(H)Bu-t units are trapped by the dilithiated M2N6 templat e. The centrosymmetric dimer {THF . Li-3[Si((NPr)-Pr-i)(3)((NHPr)-Pr-i)]}(2 ), formed by trilithiation of Si[N(H)Pr-i](4) with (LiBu)-Bu-n, forms a bic apped hexagonal prism. The tetraazasilicate (Et2O . Li)(4)[Si(Nnaph)(4)] is prepared by the reaction of SiCl4 with 4 equiv. of Li-2(Nnaph). Treatment of OP[N(H)Bu-t](3) with an excess of (LiBu)-Bu-n yields the dilithiated der ivative {(THF)Li-2[OP((NBu)-Bu-t)(2)((NHBu)-Bu-t)]}(2) with a box-shaped st ructure.