Solution-Phase Monitoring of the Structural Evolution of a Molybdenum Blue Nanoring

The inorganic host–guest complex Na22{[MoVI36O112(H2O)16]⊂[MoVI130MoV20O442(OH)10(H2O)61]}·180H2O ≡ {Mo36}⊂{Mo150}, compound 1, has been isolated in its solid crystalline state via unconventional synthesis in a custom flow reactor. Carrying out the reaction under controlled flow conditions selected for the generation of {Mo36}⊂{Mo150} as the major product, allowing it to be reproducibly isolated in a moderate yield, as opposed to traditional “one-pot” batch syntheses that typically lead to crystallization of the {Mo36} and {Mo150} species separately. Structural and spectroscopic studies of compound 1 and the archetypal Molybdenum Blue (MB) wheel, {Mo150}, identified compound 1 as a likely intermediate in the {Mo36} templated synthesis of MB wheels. Further evidence illustrating the template effect of {Mo36} to MB wheel synthesis was indicated by an increase in the yield and rate of production of {Mo150} as a direct result of the addition of preformed {Mo36} to the reaction mixture. Dynamic light scatterin...