Synthesis and characterization of the 'Japanese rice-ball'-shaped Molybdenum Blue Na4[Mo2O2(OH)4(C6H4NO2)2]2[Mo120Ce6O366-H12(OH)2(H2O)76]∼200H2O

The hybridized lanthanide-containing molybdenum blue (Ln-MB) wheel Na-4-[Mo2O2(OH)(4)(C6H4NO2)(2)](2)[Mo120Ce6O366H12(OH)(2)(H2O)(76)]similar to 200H(2)O ({Mo-2-(C6H4NO2)(2)}(2){Mo120Ce6}) 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 [Mo2O2(OH)(4)(C6H4NO2)(2)](2+). 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-2(C6H4NO2)(2)}(2){Mo120Ce6} is composed of a 24-electron reduced anionic ring, which was confirmed by Vis-NIR spectroscopy.

Automated summary

In this study, the hybridization of lanthanide-containing molybdenum blue (Ln-MB) with 2-picolinic acid was achieved, resulting in the formation of Ln-MB molecules with a unique shape. The position of the carboxylic acid group was found to be crucial in obtaining single crystals of Ln-MB. Various experimental techniques were employed to confirm the structure and composition of the synthesized molecules.