Synthesis and characterization of two novel tetranuclear sodium ketoiminate complexes; structural evidence for formation of dative Na ⋯ F and Na-C (olefin) bonding interactions
Journal
Journal of the Chemical Society, Dalton Transactions
Journal Issue
3
Pages
343-347
Date Issued
2000
Author(s)
Abstract
Treatment of fluorinated β-ketoiminate ligands MokeimH or AlkeimH with NaH in THF solution afforded the corresponding ketoiminatosodium complexes [Na(Mokeim)]41 and [Na(Alkeim)]42, MokeimH = (CF3)C(O)CHC(CF3)NH(CH2CH2OMe) and AlkeimH = (CF3)C(O)CHC(CF3)NH(CH2CHCH2). These new complexes were characterized by spectroscopic methods, elemental analyses and X-ray diffraction studies. Complex 1 consists of a tetrameric Na4O4 cubane core arrangement, of which each sodium atom is surrounded by a tridentate ketoiminato ligand, two oxygen atoms from nearby ketoiminato ligands, and one or two weak Na⋯F dative interactions. The core structure of 2 is similar, but with formation of the uncommon allyl to sodium π interaction. The stabilization of this Na–C (olefin) bonding interaction is as effective as the Na–O (ether) dative bonding in 1 because 2 shows comparable thermal stability and even an enhanced volatility during sublimation.
Type
journal article