Studies on the synthesis of Pb-Ti-oxo-alkoxo-carboxylato complexes

Article abstract of DOI:10.1016/S0277-5387(97)00525-1

Reactions between lead carboxylates Pb(O₂CR)₂ and Ti(OPr-ⁱ)₄ produce complexes of empirical formulae Pb₂Ti₂(O)(O₂CR)₂(OPr ⁱ)₈ (R = C₃F₇ 1 ; C(CH₃)₃ 2) in toluene and Pb₂Ti₄(O)₂(O₂CR) ₂(OPrⁱ)₁₄ (R = CH(CH₃)₂ 3) in PrⁱOH solution. ²⁰¹Pb NMR evidence indicates that both types of complex form in alcoholic solution. The compound 4 having a Pb₃Ti₃ core is produced when Pb(O₂CCH(CH₃)₂)₂ reacts with Ti (OPrⁱ) 4 in toluene. Attempts to prepare acetylacetonate derivatives of compounds having 1:1 or 1:2 Pb : Ti stoichiometries by direct substitution of the compounds gave poorly soluble Pb containing products but direct reaction of Pb(O₂CCH₃)₂ or PbO with Ti-acetylacetonate-alkoxide species gave compounds of empirical formulae Pb₃Ti₃(O)₄(O₂CCH₃) ₂(OPrⁱ)₇(acac) 5 and Pb₂Ti₂(O)(OEt)₈(acac)₂ 6. Reaction of Ti(OR)₄ (R = OPrⁱ, Et) with acetic acid yields products which further react with PbO to form the previously characterised Pb - Ti compounds Pb₂Ti₂(O)(O₂CCH₃) ₂(OPrⁱ)₈ 7 and Pb₂Ti₄(O)₂(O₂CCH₃) ₂(OEt),₁₄ 8. Molecular weight measurements, ²⁰⁷Pb, ¹⁹F, ¹H and ¹³C NMR and IR spectral data have been used to derive empirical formulae for the various complexes isolated.