Metal benz oylpivaloylmethanates,part I. Free ligands and copper(II) chelates

Summary Syntheses and properties ofpara-substituted benzoylpivaloylmethanes and their copper(II) chelates are described.¹H n.m.r., u.v. and i.r. spectra of free ligands indicate a very high enol content. Molecular weight determin tions showed that the bulky t-butyl and phenyl groups do not prevent association of chelates in chloroform solutions. All the chelates obey the Curie-Weiss law with the Weiss constant close to zero; magnetic moments lie within the 1.87–2.02 B.M. range over the 77–300 K range. I.r. and Raman spectra suggest that the complexes have a square planar stereochemistry and a trans geometrical structure.Reprints of this article are not available.