III International Conference

PP-I-21THE STUDYING OF THE NATURE OF ALCOHOLATE COMPLEXES OFALUMINIUM IN ALCOCHOLIC SOLUTIONSFedotov M.A., Molchanov V.V., Zotov R.N., Tuzikov F.V.Boreskov Institute of Catalysis SB RAS, Novosibirsk, RussiaE-mail: Ruslan806a@gorodok.netThe formation of alcoholate complexes of aluminium in spirit solutions with a tetrahedraland octahedral environment of aluminium, and also complexes with pentacoordinatedaluminium was shown by methods of NMR and small angle X-ray scattering.Superpure alumina is the most efficient supporter for the catalysts for reforming,hydrotreating, Fisher – Tropsh processes and some other. This alumina is obtained byhydrolysis of aluminium alcoholates. The mechanism of hydrolysis is described in literaturevery poorly. The first step of studying of the mechanism of hydrolysis of alcoholatealuminium should be studying of the nature of alcoholate complexes of aluminium in spirits(in alcocholic solution). The given research is devoted to this problem.The condition of trimethoxy-, triethoxy-, and triisopropoxyaluminium in correspondingspirits has been investigated by methods of NMR (on nucleus 13 C and 27 Al) and small angleX-ray scattering (SAXRS). The samples of solutions of aluminium alcoholate have beenobtained by interaction of metal aluminium with excess amount of corresponding alcohol(spirits). It was established, that the solution of aluminium trimethylate in methanol contains amononuclear complex [Al (OMe) 3 (HOMe)] where the atom of aluminium is in a tetrahedralcoordination, and also the complexes with tetra- and pentacoordinated aluminium. Thecomplexes are formed by solvation of the molecule of aluminium trimethylate with methanol.Two types of octahedral complexes are found in the solution of aluminium triethylate inethanol. It was shown, that there are four types of complexes: in the solution of aluminiumtriisopropylate in isopropanole: mononuclear with an octahedral coordination of aluminium,binuclear with octahedral coordination, polynuclear complexes with tetra- andpentacoordinated aluminium. It was made the assumption of a structure of complexes Alformed in solutions (fig. 1) on the basis of the NMR data and changes of type of spectradepending on temperature.It was obtained the size distribution of nanoparticles of complexes of aluminium for thesolution of aluminium triisopropylate in isopropanole by SAXRS. The calculated sizes ofmodels of complexes of aluminium triisopropylate which are shown in fig. 1 agree well with a46