Synthesis and crystal structure of zirconium complexes with fluorinated tetradentate beta-ketoiminate ligands

Two beta-ketoiminato complexes of zirconium, di[bis-trifluoroacetylacetone-ethylenediiminato]zir conium Zr(enTFA(2))(2) (1), and di [bis-trifluoroacetylacetone-trimethylenediiminato]zirconium, Zr(trimenTFA(2))(2) (2), have been obtained in high yield from the reaction of ZrCl4 and the sodium salt of the corresponding Schiff base. The compounds have been characterized by elemental analysis, NMR, mass spectrometry and X-ray structure determination. The coordination geometry around the zirconium atom is a dodecahedron in 1 and a square antiprism in 2. The increase of the aliphatic bridging chain of the ligand does not produce significant changes in the Zr-O-av bond distances [2.101(2) in 1 and 2.086(4) Angstrom in 2] while the Zr-N-av. bond distances are lengthened [2.432(4) in 1 and 2.491(5) Angstrom in 2]. Copyright (C) 1997 Elsevier Science Ltd.