Structure of a pentamanganese(II)–phenoxide cluster with a central five‐coordinate oxide: MnII5(μ‐OPh)6(μ3‐OPh)2(μ5‐O)(Py)6·Py (Py is pyridine). Issue 3 (13th February 2017) - Hamilton, Clifton R.
Abstract : We report here the structure of the Mn II 5 (μ‐OPh)6 (μ3 ‐OPh)2 (μ5 ‐O)(Py)6 molecular cluster containing an unusual central trigonal bipyramidal oxide, and compare its geometry to three analogous metalloclusters. While the structures are similar overall, the apical metal site shows the greatest contrast with the other reported first‐row transition metal systems, having a larger bond distance than the Ti system, and a shorter contact than the Fe system. Abstract : Polynuclear metal clusters frequently feature geometric structural features not common in traditional coordination chemistry. These structures are of particular interest to bioinorganic chemists studying metallocluster enzymes, which frequently possess remarkably unusual inorganic structures. The structure of the manganese cluster μ5 ‐oxido‐di‐μ3 ‐phenoxido‐hexa‐μ‐phenoxido‐hexakis(pyridine‐κ N )hexamanganese(II) pyridine monosolvate, [Mn5 (C6 H5 O)8 O(C5 H5 N)6 ]·C5 H5 N or Mn II 5 (μ‐OPh)6 (μ3 ‐OPh)2 (μ5 ‐O)(Py)6 ·Py, containing an unusual trigonal bipyramidal central oxide, is described. The compound was isolated from a reaction mixture containing bis(trimethylsilylamido)manganese(II) and phenol. The central O atom is presumed to have originated as adventitious water. The molecule crystalizes in a primitive monoclinic crystal system and is presented in the centrosymetric P 2/ n space group. The molecule possesses crystallographically imposed twofold symmetry, with the central O atom centred on the twofold axis and surrounded by a distorted trigonal bipyramidal arrangement of Mn atoms, which are further bridged by phenoxide ligands, and terminally ligated by pyridine. A pyridine solvent molecule resides nearby, also situated on a crystallographic twofold axis. The cluster is compared to three closely related previously reported structures.