Volatile square planar β-imino carbonyl enolato complexes of Pd(II) and Ni(II) as potential MOCVD precursors

A series of palladium(II) and nickel(II) [ML2] complexes (1-6: 1, Pd, LMe; 2, Pd, LiBu; 3, Pd, LnBu; 4, Pd, LnHe; 5, Ni, LMe; 6, Ni, LiBu) has been synthesised by reacting the proper acetato salt with the β-enamino ketoesters (MeCO)(MeOCO)CC(NH2)R (R = Me, i-Bu, n-Bu, n-hexyl). The chain length has practically no effect on the output of the synthetic procedure so that complexes are obtained always in good yields. They are all square planar and the potentially tridentate ligand is coordinated via the N,O donor atoms of the imino and keto groups. Their thermal behaviour has been fully studied and [Ni(LMe)2] demonstrated to be a convenient precursor for the Metal Organic Chemical Vapour Deposition of Ni and NiO thin films.

Graphical abstractReaction of nickel and palladium acetates with a series of β-enaminodiones affords thermally stable, volatile square planar complexes.Figure optionsDownload full-size imageDownload as PowerPoint slide