Structure and Properties of Ni(II) Complexes with Heptanedione-3.5

The influence of the size of the β-diketonate ligand substituent on the structure and thermal properties of volatile Ni(II) complexes is determined. To this aim, a corresponding heptanedione-3.5 (Hhd) derivative is prepared. The structures of [Ni₃(hd)₆] and its derivatives [Ni₄(OMe)₄(hd)₄(MeOH)₄] and [Ni₃(OH) (hd)₅(H₂O)]₂ are studied by XRD. The trinuclear complex is similar to its simplest β-diketonate analogue. Such a tetranuclear structure is typical for mixed-ligand alkoxy-β-diketonate divalent metal complexes, whereas the hexuclear structure is unique. Thermal properties of Ni(II) β-diketonates in the series L = RC(O)CHC(O)R, R = Me, Et, tBu are compared by the thermogravimetry method.