STUDIES ON THE SYNTHESIS OF PB-TI-OXO-ALKOXO-CARBOXYLATO COMPLEXES

Reactions between lead carboxylates Pb(O2CR)(2) and Ti(OPri)(4) produc e complexes of empirical formulae Pb2Ti2(O)(O2CR)(2)(OPri)(8) (R = C3F 7 1; C(CH3)(3) 2) in toluene and Pb2Ti4(O)(2)(O2CR)(2)(OPri)(14) (R = CH(CH3)(2) 3) in (PrOH)-O-i solution. Pb-207 NMR evidence indicates th at both types of complex form in alcoholic solution. The compound 4 ha ving a Pb3Ti3 core is produced when Pb(O2CCH(CH3)(2))(2) reacts with T i(OPri)(4) in toluene. Attempts to prepare acetylacetonate derivatives of compounds having 1:1 or 1:2 Pb:Ti stoichiometries by direct substi tution of the compounds gave poorly soluble Pb containing products but direct reaction of Pb(O2CCH3)(2) or PbO with Ti-acetylacetonate-alkox ide 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(O R)(4)(R = OPri, Et) with acetic acid yields products which further rea ct with PbO to form the previously characterised Pb-Ti compounds Pb2Ti 2(O)(O2CCH3)(2)(OPri)(8) 7 and Pb2Ti4(O)(2)(O2CCH3)(2)(OEt)(14) 8. Mol ecular weight measurements, Pb-207, F-19, H-1 and C-13 NMR and IR spec tral data have been used to derive empirical formulae for the various complexes isolated. (C) 1998 Elsevier Science Ltd. All rights reserved .