A Post-Functionalizable Iso-Polyoxotitanate Cage Cluster

Abstract

During solvothermal alcoholysis of a mixture of TiI4 and Ti(O(i)Pr)4, a {I@Ti22} cage cluster encapsulating an OH and iodide guests is crystallized. The {I@Ti22} host-guest cluster surface is postfunctionalizable with catecholate and carboxylate ligands. The synthetic details, structural characterization, spectroscopic properties of the obtained cages clusters are provided. The present study provides candidates for modeling ligand exchange and electron-hole transfer at the titanate nanoparticle surface, and meanwhile offers new opportunities for understanding the TiO2 nanocrystalline formation in solvothermal processes.

Functionalization of Titanium Oxide Cluster Ti17O24(OiC3H7)20 with Catechols: Structures and Ligand‐Exchange Reactivities

“…In addition to the monodentate and the chelate‐bidentate modes, in our previous study of a larger ellipsoidal Ti 22 cluster compound, fully deprotonated DTBC binds to the surface following the chelate‐bridging mode (Figure ) . According to a survey of the Cambridge Structural Database (CSD), chelate‐bidentate and chelate‐bridging modes are generally the most typical binding modes of catecholates on the surface of Ti oxide clusters (see the analysis in Table S2 in the Supporting Information), consistent with the reports by Coppens and Henry …”

“…carefully studied the ligand‐exchange reactions of Ti 16 O 16 (OEt) 32 with alcohols . We also obtained the functionalized product of [I@Ti 22 O 32 (O i C 3 H 7 ) 23 H] + cluster with 3,5‐di‐ tert ‐butylcatechol (H 2 DTBC) . Among the known Ti oxide clusters, Ti 17 O 24 (O i C 3 H 7 ) 20 (Ti 17 ) is very important because it is one of the oldest Ti oxide clusters and exhibits the classic Keggin structure (Figure ) .…”

Binding Modes of Salicylic Acids to Titanium Oxide Molecular Surfaces

“…and other studies on dye/TiO 2 hybrids . Structurally, the O/Ti ratios (also known as condensation degrees) of these TOCs are larger than those of the TCCs in Figure . We then calculated the electron densities of the initial states.…”

“…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 .…”

“…Interestingly, {Ti 4b } is assembled by one, {Ti 7 } is assembled by two, and {Ti 13 } is constructed by three ladder‐like (Ti‐μ 3 ‐O) 4 building blocks in a crisscross pattern. Hence, they are structurally analogous to anatase TiO 2 , which is also comprised of the same zigzag (Ti‐μ 3 ‐O) ∞ ladder‐like building blocks (see Figure S1 in the Supporting Information for a structural comparison). The other TOCs also contain the zigzag (Ti‐μ 3 ‐O) n building blocks but the (Ti‐μ 3 ‐O) n building blocks are connected in other ways like edge‐to‐edge.…”