Does anion-cation organization in Na+-containing X-ray crystal structures relate to solution interactions in inhomogeneous nanoscale environments: Sodium-decavanadate in solid state materials, minerals, and microemulsions

Abstract Bonding is commonly examined in the solid state and determined by placement of atoms and molecules. Bonding in solution is equally important but much less accessible because these systems are more fluid and thus difficult to characterize the exact bonding motifs. This paper gleans information from the bonding in solid-state structures including more complex mineral systems with varying microenvironments to the bonding within inhomogeneous solutions at the nanoscale. The analysis for the solid state uses structurally well-described anion systems combined with a range of cations and their association in the solid state of both synthetic and naturally-occurring materials, minerals. Detailed solid-state structural information is available on the >180 decavanadate structures reported, however, because the structures will be compared with aqueous nanodroplets of dissolved decavanadate captured within reverse micelles, the abundant Na + cations stabilizing the reverse micellar interface formed with anionic surfactant focuses the current comparison to Na + -containing materials. As a result the structures observed for the Na + -containing decavanadate materials led to identification of the Na + -containing subclusters and the information is used to provide information on the decavanadate in nanosized water droplets found when a decavanadate anion associating with an Na + interface in a bis-2-ethylhexyl-sulfosuccinate (AOT) reverse micelles.