A reaction of acetylacetone with the framework sandwich type metallosiloxanes (MOS) of general formula [PhSiO 2 ] 6 M 6 [PhSiO 2 ] 6 , where M = Cu, Ni, Mn, was studied by GPC, 1 H and 29 Si NMR spectroscopy, X ray diffraction, elemental and functional analysis. The reaction involved replacement of the metal atoms with the hydrogen atoms and is accompanied by the formation of the corresponding chelate complexes M(acac) 2 . Displacement of the metal from the framework MOS leads to the destruction of molecular skeleton and formation of phenylsiloxanes containing Si-OH groups. The yield and composition of the reaction products considerably depend on the nature of the metal in [PhSiO 2 ] 6 M 6 [PhSiO 2 ] 6 . A selective substitu tion of the metal leads to the stereoregular hexahydroxyhexaphenylcyclohexasiloxane, [PhSiO(OH)] 6 , cis isomer. The structure and composition of the crystalline hexahydr oxyhexaphenylcyclohexasiloxane obtained were confirmed by 29 Si NMR spectroscopy, X ray diffraction study, and functional analysis, while its TMS derivative was studied with 1 H NMR spectroscopy and GPC. Using a framework manganese phenylsiloxane as an example, a revers ible character of the process has been established and an alternative synthesis of this compound from hexahydroxyhexaphenylcyclohexasiloxane and Mn(acac) 2 has been accomplished for the first time.Lately, organometallosiloxanes (MOS) attract increas ing interest due to their specific structure and reactivity. 1-7 Unusal chemical properties of MOS are due to the presence of differing (Si)O-Si and (Si)O-M bonds, the former of which is susceptible to nucleophilic agents, whereas the latter is easily destroyed upon the action of electrophiles.Upon preparation of MOS with trifunctional (orga nosilsesquioxane) structural units RSiO 3/2 , a mixture of individual crystalline MOS with polymeric metallosilox anes is formed. In the case of individual MOS, the archi tecture of metal complexes formed has a complex spatial structure in the form of cellular three dimensional net work, whose formation is determined by a decisive role of coordination properties of the transition metal ions 1,2 forming the metal clusters.The most acquainted representatives of individual framework type MOS containing 3d transition metals are the sandwich structure metal complexes, in which metal atoms are placed in the central plane as the [M n ] clusters flanked by two cyclosiloxane ligands bound with the M II ions by covalent and coordination metallosiloxane bonds.A unique structural organization of the framework MOS is responsible for the possibility of their application as synthons for the organoelement synthesis, 3 as well as metal containing precursors in the synthesis of new cata lysts, 4 preparation of metalloceramic materials, 5 and for development of metal containing nanocomposites. 6,7When we started our work, information on the reactiv ity of MOS in the disintegration reactions based on the cleavage of the metal oxide (Si)O-M bonds was rather limited and was basically on the reactio...
