Crystal structure of a mixed-valence µ-oxide Sn12 cluster.

ABSTRACT

The mixed-valence µ-oxide Sn12 cluster, deca-carbonyl-tetra-µ4-oxido-hexa-µ3-oxido-tetra-kis-[µ-2,2'-(pyridine-2,6-di-yl)bis(1,1-di-phenyl-ethano-lato)]deca-tin(II)ditin(IV)dimolyb-denum(O)(2 Mo-Sn) toluene hepta-solvate, [Mo2Sn12(C33H27NO2)4O10(CO)10]·7C7H8, has a crystallographically imposed inversion centre. The asymmetric unit also contains three and a half toluene solvent mol-ecules, one of which is disordered about a centre of symmetry. The complex mol-ecule comprises six distinct Sn atom species with four different coordination numbers, namely 3, 4, 5, and 6. The Sn(II) atoms forming the central Sn10O10 core adopt distorted trigonal-pyramidal, square-pyramidal and octa-hedral coordination geometries provided by the µ-oxide atoms and by the O- and N-donor atoms of two pyridinedi-ethano-late ligands. The terminal Sn(IV) atoms have distorted trigonal-bipyramidal coordination geometries, with a µ4-oxide atom and the N atom of a pyridinedi-ethano-late ligand occupying the axial positions, and the Mo atom of a Mo(CO)5 group and the alk-oxy O atoms of a ligand forming the equatorial plane. In the crystal, weak intra- and inter-molecular C-H⋯O hydrogen bonds are observed.