Cubism

The syntheses of [Li2(salen)(DME)]2, [Li2(salpn)(THF)]2, [Na2(salpn)(Et2O)]2 and [Na2(salpn)(DME)]2 (H2salen = (o-HOC6H4CHdouble bond; length as m-dashNCH2)2; H2salpn = (o-HOC6H4CHdouble bond; length as m-dashNCH2)2CH2) involve treatment of the appropriate Schiff base with either n-BuLi or MN(SiMe3)2 (M = Li, Na) in DME, THF or Et2O. The X-ray crystal structures of these compounds show that they all have very similar structural motifs comprising M4O4 (M = Li or Na) ‘cubanoid’ cores. The synthesis and X-ray crystal structure of [{Nd(salpn)(THF)Cl}{LiCl(THF)}2]2 obtained by treatment of [Na2(salpn)(THF)] with [NdCl3 · 2(LiCl)] has a dimeric [Nd(salpn)(THF)Cl]2 molecule sandwiched between two Li2Cl2(THF)2 units.