p -Block metal complexes with bis(pyrazol-1-yl)acetato ligands.

The hetereoscorpionate ligands bis(pyrazol-1-yl)acetic acid (Hbpza) and bis(3,5-dimethylpyrazol-1-yl)acetic acid (Hbdmpza) are reacted with [Sn(OAc) 2 ] or [Sn(acac) 2 ] to yield the corresponding Sn(II) complexes. A single crystal X-ray determination for the in solution monomeric complex [Sn(bpza) 2 ] (1a) revealed a dinuclear molecular structure [Sn 2 (bpza) 4 ] (1b), with κ 3 -N,N,O-coordinated bpza ligands at each of the Sn(II) and two bpza ligands μ-bridging between the Sn(II) centres. The molecular structure of [Sn(bdmpza) 2 ] (2) exhibits a homoleptic bisligand complex with both ligands displaced by the free electron pair, which is proven by DFT calculations. Oxidation of complex 2 in an attempt to synthesize a homoleptic Sn(IV) complex leads to the formation of [Sn(bdmpza)F 3 ] (3). In addition, homoleptic bisligand gallium complexes [Ga(bdmpza) 2 ][ClO 4 ] (4) and [Ga(bpza) 2 ][GaCl 4 ] (5) were prepared and characterized by 71 Ga NMR and IR spectroscopy as well as by X-ray crystallography.