Synthetic and Structural Studies of Ethyl Zinc β-Amidoenoates and β-Ketoiminates.

A set of heteroleptic ethyl zinc β-amidoenoates (1, 2) and β-ketoiminates (3) of the form [LZnEt]2 with varying steric bulk have been synthesised via the reaction of diethylzinc with β-aminoenoate ligands HL1 and HL2 and β-ketoimine HL3. These complexes have been characterised via 1H and 13C NMR, mass spectrometry and single-crystal X-ray diffraction, which unambiguously determined all three structures as dimeric species in the solid state. We observe the unusual dimerisation of 1 and 2 through coordination of the central zinc atom to the methine carbon of the second monomer, which gives these complexes high reactivity. The thermal properties of complex 3 are explored via thermal gravimetric analysis (TGA), to investigate their potential as single-source precursors to zinc oxide, which shows that 3 has a significantly lower decomposition temperature as compared to its bis-ligated counterpart [Zn(L3)2], which gives 3 promise as a single-source precursor to zinc oxide.