Synthesis and structural studies of group 12 oxazoline-enolate coordination complexes of (Z)-1-R-2-(4',4'-dimethyl-2'-oxazolin-2'-yl)-eth-1-en-1-ates; part I: the zinc derivatives

The synthesis and characterisation (IR, NMR, HR-MS, and X-ray crystallography) of six oxazoline Zn complexes, containing enolate ligands derived from a series of (Z)-1-R-2-(4',4'-dimethyl-2'-oxazolin-2'-yl)-eth-1-en-1-ols (R = C6H5, C6H4-p-NO2, C6H4-p- OCH3, CF3, CH3, or CMe3) is detailed. All derivatives are air-stable solids of formula Zn(Ln)2 and are formed in the presence of the title ligands and NEt3. Reasonable yields (53%-82%) are obtained with the exception of R = CMe3 (9%); in this case, by-product formation and high solubility affected complex isolation. Crystallographic characterisation reveals that in all cases the ligands are bound in a kappa 2-N, O-bonding motif. Little structural diversity is noted within the series; these complexes are further placed into structural context with related Zn materials containing oxazoline, phenolate, and (or) Schiff base ligands.