HIGHLY DISORDERED CLUSTER COMPOUND Ti₄O₄(Me₂PhO)₄[(CO)₉Co3CCO₂]₄. Maoyu Shang, Xinjian Lei, Thomas P. Fehlner, Dept. of Chem. & Biochem., University of Notre Dame, Notre Dame, IN 46556.

The reaction of the cluster substituted carboxylic acid (CO)₉Co₃CCO₂H with Ti(OR)4 produces a series of new compounds, Ti₄(u-O)₄(OR)₄[u-O₂CCCo₃(O)₉]₄, with a cube-like core Ti₄O₄. When R = Me₂Ph-, the structure is unusually disordered, but solved and refined satisfactorily with the help of SHELXL-93. The cube-like core has a 90deg. rotational disorder so that each apex is occupied by 50% Ti and 50% O, however, Me₂PhO^- is dislocated to a position other than the 90deg. rotation. Except for the rotation of the -CO₂^- part, (CO)₉Co₃CCO₂^- remains intact.