Bis(N,N′-disalicylidene-3,4-phenylenediamine-1-ethylbenzoato)zirconium(IV), an eight-coordinate chelate with linear polymerization possibilities

Synthesis of the Schiff-base complex bis(N,N′-disalicylidene-3,4-phenylenediamine-1-ethylbenzoato)zirconium(IV), which has two, linearly disposed, uncoordinated ester groups, has been accomplished from the reaction of a zirconium alkoxide with the new Schiff ligand N,N′-disalicylidene-3,4-phenylenediamine-1-ethylbenzoate. The ligand itself was isolated in two forms, yellow and orange, which are believed to be tautomers based on infrared data. Elemental analyses, IR, NMR, and UV-Visible data are included for all new compounds, as well as mass spectral data for the complex. Broadening of ¹H NMR resonances in the complex spectrum, relative to TMS and ethanol of solvation resonances, may be indicative of a slow molecular motion. Preliminary attempts to polymerize the complex with aromatic amines failed, however, due to decomposition of the metal chelate unit at the high temperatures (300°C) required.