PREPARATION AND STRUCTURE OF A MANGANESE ANTIMONY MU(5)-OXO ETHOXIDE, MN8SB4(MU(5)-O)(4)(MU(3)-OET)(4)(MU-OET)(16)

A new bimetallic manganese antimony ethoxide has been prepared by reacting anhydrous MnCl2 with NaSb(OEt)(4) in a toluene/ethanol solution under inert atmosphere. Single-crystal X-ray diffraction investigations carried out at -103 degrees C show that the molecular formula of the ethoxide is Mn8Sb4O4(OEt)(20). The compound-crystallizes with space group symmetry C2/c and with the unit cell parameters a = 17.565(6) Angstrom, b = 17.578(7) Angstrom, c = 21.870(5) Angstrom, beta = 93.37(5)degrees, and Z = 4. The crystal structure model was refined to an R value of 0.050 (R(W) = 0.062) against the 3393 most significant reflections. The packing of the rather spherically shaped molecules in the crystal structure can be described as being approximately body-centered cubic. The molecular geometry has an approximate S-4 point symmetry. The antimony(III) atoms are five-coordinated by oxygen atoms. Four of the manganese(II) atoms are approximately octahedrally coordinated, while the remaining four manganese atoms are five-coordinated with a distorted square pyramidal coordination. Four of the oxygen atoms are of mu(5)-oxo type with a coordination geometry of distorted square pyramids.