Aqueous Bismuth Titanium–Oxo Sulfate Cluster Speciation and Crystallization

Abstract

Inorganic aqueous metal-oxo clusters are both functional "molecular metal oxides" and intermediates to understand metal oxide growth from water. There has been a recent surge in discovery of aqueous Ti-oxo clusters but without extensive solution characterization. We use small-angle and total X-ray scattering, dynamic light scattering, transmission electron microscopy, and a single-crystal X-ray structure to show that heterometals such as bismuth stabilize labile Ti-oxo sulfate clusters in aqueous solution.[Ti Bi O (OH)(OH ) (SO ) ] features edge-sharing between the Ti and Bi polyhedra, in contrast to the dominant corner-linking of Ti-oxo clusters. Bi stabilizes the Ti-polyhedra, which are synergistically stabilized by the bidentate sulfates. Gained stability and potential functionality from heterometals is an incentive to develop more broadly the landscape of heterometallic Ti-oxo clusters.

Binding Modes of Salicylic Acids to Titanium Oxide Molecular Surfaces

“…During this process, 2 equivalents of H 2 O required for the complete hydrolysis and condensation of the Ti IV precursors like Ti(O i C 3 H 7 ) 4 into TiO 2 are generated in situ by the etherification of isopropanol . Many TOCs of different condensation degrees and structures, also known as prenucleation clusters of TiO 2 nanocrystals, are formed in the mother liquor before TiO 2 formation (Scheme ). In this study, H 2 SSAs are used as additives during the hydrothermal treatment of Ti(O i C 3 H 7 ) 4 .…”

The Role of Bi3+ in Promoting and Stabilizing Iron Oxo Clusters in Strong Acid

“…Recently, we used Bi 3+ to isolate the Keggin cluster [FeO 4 Fe 12 O 12 (OH) 12 L 12 ] 17− (L=CCl 3 COO − or CF 3 COO − ) from water . These studies showed that Bi stabilizes this reactive iron oxyhydroxide intermediate, and this synthetic strategy was later employed to isolate Ti 4+ polyoxocations, suggesting broader utility . We could not successfully adapt the role of Bi 3+ to other lone pair p‐block metals or Ln 3+ metals in stabilizing and promoting metal oxo cluster growth in water.…”

“…[15,16] These studies showed that Bi stabilizes this reactive iron oxyhydroxide intermediate,a nd this synthetic strategy was later employed to isolate Ti 4+ polyoxocations, suggesting broader utility. [17] We could not successfully adapt the role of Bi 3+ to other lone pair p-block metals or Ln 3+ metals in stabilizing and promoting metal oxo cluster growth in water. Therefore,wemust understand the unique character of bismuth to further exploit it in this role.T owards this goal and also towards determining the reaction pathway from the Fe(aq) monomer to the Fe Keggin ion, we have isolated and structurally characterized af ragment of the Bi-capped iron Keggin ion, Fe 3 BiO 2 (CCl 3 COO) 8 (THF)(H 2 O) 2 (BiFe 3 ).…”

The Role of Bi3+ in Promoting and Stabilizing Iron Oxo Clusters in Strong Acid

“…[15,16] These studies showed that Bi stabilizes this reactive iron oxyhydroxide intermediate,a nd this synthetic strategy was later employed to isolate Ti 4+ polyoxocations, suggesting broader utility. [17] We could not successfully adapt the role of Bi 3+ to other lone pair p-block metals or Ln 3+ metals in stabilizing and promoting metal oxo cluster growth in water. Therefore,wemust understand the unique character of bismuth to further exploit it in this role.T owards this goal and also towards determining the reaction pathway from the Fe(aq) monomer to the Fe Keggin ion, we have isolated and structurally characterized af ragment of the Bi-capped iron Keggin ion, Fe 3 BiO 2 (CCl 3 COO) 8 (THF)(H 2 O) 2 (BiFe 3 ).…”