Synthesis and characterization of the `Japanese rice-ball'-shaped Molybdenum Blue Na[MoO(OH)(CHNO)][MoCeOH(OH)(HO)]∼200HO.

The hybridized lanthanide-containing molybdenum blue (Ln-MB) wheel Na[MoO(OH)(CHNO)][MoCeOH(OH)(HO)]∼200HO ({Mo(CHNO)}{MoCe}) was assembled in an aqueous one-pot synthesis. The Ln-MB was hybridized with 2-picolinic acid through the generation of the organometallic counter-ion [MoO(OH)(CHNO)]. Control experiments demonstrated that the position of the carboxylic acid group (2-position to the N atom) in the hybridization component is critical in yielding single crystals of Ln-MB. In addition to single-crystal X-ray diffraction (XRD) analysis, which revealed a `Japanese rice-ball'-shaped Ln-MB as the anion, elemental analyses, IR spectroscopy, and thermogravimetric analysis (TGA) were performed to confirm its structure and composition. Bond-valence-sum calculations (BVS) revealed that {Mo(CHNO)}{MoCe} is composed of a 24-electron reduced anionic ring, which was confirmed by Vis-NIR spectroscopy.