Pentakis(μ3-N,2-dioxidobenzene-1-carboximidato)di-μ2-formato-pentakis(1H-imidazole)methanolpentamanganese(III)manganese(II)–methanol–water (1/3.36/0.65)

• Main Authors: Benjamin R. Tigyer, Matthias Zeller, Curtis M. Zaleski
• Format: Article
• Language: English
• Published: International Union of Crystallography 2012-12-01
• Series: Acta Crystallographica Section E
• Online Access: http://scripts.iucr.org/cgi-bin/paper?S1600536812047228

The title compound, [Mn6(C7H4NO3)5(CHO2)2(C3H4N2)5(CH3OH)]·3.36CH3OH·0.65H2O, or Mn(II)(O2CH)2[15-MCMn(III)N(shi)-5](Im)5(MeOH)·3.36MeOH·0.65H2O (where MC is metallacrown, shi3− is salicylhydroximate, Im is imidazole and MeOH is methanol), contains five MnIII ions as members of the metallacrown ring and an MnII atom bound in the central cavity. The central MnII atom is seven-coordinate with a geometry best described as between face-capped trigonal–prismatic and face-capped octahedral. Three MnIII ions of the metallacrown ring are six-coordinate with distorted octahedral geometries. Of these six-coordinate MnIII ions, two have mirror-plane configurations, while the other has a Δ absolute stereoconfiguration. The remaining two MnIII ions have a coordination number of five with a distorted square-pyramidal geometry. The five imidazole ligands are bound to five different MnIII ions. Disorder is observed for one of the coordinating imidazole ligands, as the imidazole ligand is disordered over two alternative mutually exclusive positions in a ratio of 0.672 (9) to 0.328 (9). The interstitial voids between the main molecules that constitute the structure are mostly filled with methanol molecules that form hydrogen-bonded chains. Some of the sites of the non-coordinated methanol molecules are not fully occupied, with the remainder of the volume either empty or taken up by ill-defined close to amorphous content. One site was refined as being taken up by either two or one methanol molecules, with an occupancy ratio of 0.628 (5) to 0.343 (5). This disorder might thus be correlated with the disorder of the imidazole ring (an N—H...O hydrogen bond between the major moieties of the imidazole and the methanol molecules is observed). On the other side of the disordered imidazole ring the chain of partially occupied methanol molecules originates that extends via O—H...O hydrogen bonds to the metal-coordinated methanol molecule. The three partially occupied methanol molecules were refined to be disordered with two water molecules to take two residual electron density peaks into account (the exact nature of these weak residual electron density peaks cannot be deduced from the X-ray diffraction data alone, the assignment as water is tentative). The occupancy rate for the methanol molecules refined to 0.480 (7). The occupancy rate of the two water molecules refined to 0.34 (1) and 0.31 (2) for each site.