Studies on 3-oxo-N-phenylbutanamides and their metal chelates.

Ten compounds of the type CH3.CO.CHR.CO.NH.C6H5 have been prepared where R = -CH3, -C2H5, -n-C3H7, -i-C3H7, -n-C4H9, -i-C4H9, -Cl, -Br, -I and -SCN. Of these, only the -Cl, -Br, -I and - SCN derivatives and the parent compound (R = H) are capable of forming metal chelates, and the reasons for this are discussed. Metal chelates have been prepared with copper (II), iron (III) and chromium (III) ions. Proton nuclear magnetic resonance, infra-red and ultra-violet/visible spectroscopic techniques have been used to study the keto-enol equilibria of the compounds together with solvent and substituent effects and the crystal field spectra of the metal chelates. The decomposition of the compounds and some of the metal chelates have been investigated under the gas phase conditions of the mass spectrometer and under aqueous alkaline conditions. Similarities between the decomposition routes and the effect of the 2-substituent are discussed.