Derivatives of divalent germanium, tin, and lead. Part IX. Tin(II) derivatives of alkyl acetoacetates, 4-phenylbutane-2,4-dione, 1,3-di-phenylpropane-1,3-dione, cyclohexane-1,2- and -1,3-diones, and 2-hydroxycyclohepta-2,4,6-trien-1-one

Abstract

Tin(II) derivatives of the title compounds have been synthesised by reaction of the dione with bis(methylcyclo-pentadienyl)tin(II). The low values of the carbonyl-stretching vibration in the i.r. region indicate that all the diones except cyclohexane-1,3-dione function as bidentate ligands towards tin. N.m.r. and tin-119m Mössbauer data have been recorded and interpreted in terms of pseudo-trigonal-bipyramidal co-ordination of Sn^II. Evidence for the occurrence of an exchange process in solution has been obtained for the 2-hydroxycyclohepta-2,4,6-trien-1-one derivative. This compound is unusually stable towards oxidation and the observation of [(H₅C₅)Sn]⁺ and [(HC₂)-Sn]⁺ fragments in the mass spectrum indicates possible association of the metal with carbon rather than oxygen in the [(C₇H₅O₂)Sn]⁺ ion. Mass spectra of the 4-phenylbutane-2,4-dione and 1,3-diphenylpropane-1,3-dione derivatives have also been recorded.