STRUCTURAL INVESTIGATIONS OF BIMETALLIC Sb³⁺ ETHOXIDES AND A COMPARISON TO RELATED STRUCTURES.

U. Bemm and R. Norrestam, Department of Structural Chemistry, Stockholm University. S-106 91 Stockholm, Sweden.

By an systematic investigation of the Ni²⁺ and Mn²⁺ antimony ethoxide systems [1] several species are found. Seven of these compounds have been structurally investigated, e.g. Ni₆Sb₄O₄(OEt)₁₆(HOEt)₄ (I) [2], Mn₇Sb₄O₄(OEt)₁₈(HOEt)₂ (II) [4] and Mn₈Sb₄O₄(OEt)₂₀ (III) [3], by single-crystal X-ray diffraction methods. Some of the species are structurally quite similar and have been investigated for further structural relationships, see e.g. figure below. The obtained metal and oxygen atom core fragments of the investigated structures have also been compared to other alkoxides and related compounds found with the Cambridge Structural Database System, CSDS. 90 structures were retrieved from the database and the investigation has resulted in a simple classification of the MxOy type, where the core fragment can be further described with the relation [u₃,u₄,u₅][m₁,m₂,m₃,m₄,m₅,m₆]. u_a and m_b are the coordinations around the oxygen atoms and the metal atoms, respectively. 90% of the retrieved structures can be classified and divided into ten sub-proups.

Figure Comparison of the metal and oxo-oxygen atom core fragment of the three structures I, II and III,respectively.

[1] Westin,G.; Nygren, M. (1994). J. Mater. Chem. 4(8), 1275

[2] Bemm,U.; Norrestarn, R.;Nygren, M.; Westin, G. (1993). Inorg Chem. 32, 1597 [3] Bemm,U.; Norrestam, R.; Nygren, M.; Westin, G. (1995). Inorg Chem. 34, 2367 [4] Bemm,U.; Norrestam, R.;Nygren, M.;Westin, G. (1996) J. Solid State Chem.. subm.