Crystallography and Mass-Spectrometry of Heptanuclear Disk Mn(II) Cluster

(1-methyl-1H-benzo[d]imidazol-2-yl) methanol (Hmbm) reacts with Mn(ClO4)(2)center dot 6H(2)O to form heptanuclear disks [Mn-7(mbm)(12)]center dot 2(ClO4) (1) under ambient conditions. The heptanuclear cluster was previously described as a double calix unit with the hydroxides in the middle. The seven Mn(II) ions are essentially coplanar as expected for all edge-sharing octahedra, which can be intituled as a segment of Mg(OH)(2) layer of brucite, so it is a symmetric disk. ESI-MS of crystals showed its stability in solution. Time-dependent mass spectrometry (MS) from solutions at different period of the assembly reveal a hierarchical sequence, [Mn-III(mbm)(2)](+) -> [Mn-2(II)(mbm)(3)](+) -> [Mn-4(II)(mbm)(6)(ClO4)](+) -> [(MnMn6II)-Mn-III(mbm)(12)(ClO4)(2)](+).

Automated summary

The reaction of Hmbm with Mn(ClO4)(2) at ambient conditions forms a heptanuclear disk structure, described as symmetrical. ESI-MS analysis shows its stability in solution. Time-dependent MS analysis reveals a hierarchical assembly process.