Insights in the sol-gel processing of Pb(Mg1/3Nb2/3)O-3. The synthesis and crown structure of a new lead magnesium cluster: Pb6Mg12(mu-OAc)(6)( mu(2), eta(2)-OAc)(18)(mu(3), eta(2)-OC2H4OPri)(12)

The synthesis and molecular structure of a Pb-Mg bimetallic acetatoalkoxide (Pb-6,Mg-12( mu-OAc)(6)(mu(2), eta(2)-OAc)(18)(mu(3), eta(2)-OC2H4OPr1)(12), space group R-3, a = b = 30.032(2), c = 18.855(2) Angstrom, alpha = beta = 90degrees, gamma = 120degrees) are discussed in this article. This compound was isolated as an intermediate during the elaboration of Pb(Mg1/3Nb2/3)O-3 (PMN) using sol-gel process. It results from the reaction of a bimetallic Mg/Nb species with lead acetate in 2-isopropoxyethanol. (C) 2002 Elsevier Science B.V. All rights reserved.