Water-Soluble and Ultrastable Ti₄L₆ Tetrahedron with Coordination Assembly Function

Abstract

We have successfully constructed a tetrahedral TiL cage with calixarene-like coordination-active vertices. It further features high solubility and stability in HO and DMF/HO solution, affording an interesting stepwise assembly function with other metal ions. Through trapping of different amounts of Co or Ln ions, the TiL tetrahedra can be organized into various dimensional architectures, including a TiL-Co cage, a TiL-Ln cage, a TiL-Ln chain, and a three-dimensional TiL-Ln framework. An unusual mixed-valence phenomenon was observed in the TiL cage, whose Ti compositions were adequately identified by electron spin resonance and X-ray photoelectron spectroscopy analyses. More remarkably, the calixarene-like oxygen vertices of the TiL cage can also be used for the recognition of C-symmetric dye molecules through N-H···O hydrogen bonding. Accordingly, driven by visible light, selective and efficient homogeneous photodecomposition of acid blue 93 and alkali blue 4B were successfully achieved. Therefore, this work not only represents a milestone in constructing symmetric Ti-based cages with interesting coordination assembly function but also provides a new method for preparing technologically important soluble photoactive cages.

Host–Guest and Photophysical Behavior of Ti8L12 Cube with Encapsulated [Ti(H2O)6] Species

“…However, compared to the numerous reports on TiO 2 and TOCs, the research in Ti‐based coordination cages is still in its rudimental stage . Tetrahedral Ti 4 L 4 and Ti 4 L 6 cages constructed firstly by Raymond and recently by us represent the few well‐characterized examples in this field . Thus, there is still plenty of room for the development of Ti‐organic cages, especially those with interesting host–guest photophysical behavior.…”

“…[29][30][31] Tetrahedral Ti 4 L 4 and Ti 4 L 6 cagesc onstructed firstly by Raymond and recently by us represent the few well-characterized examples in this field. [32][33][34] Thus,t here is still plenty of room for the development of Ti-organic cages, especially those with interestingh ost-guest photophysical behavior.…”

Designable Aluminum Molecular Rings: Ring Expansion and Ligand Functionalization

“…[13][14][15][16][17][18][19] More importantly,o rganoaluminium with highly tailorable shape,c omposition, and surface properties represents an excellent platform for significant atomistic understanding.H owever, the fast hydrolysis of aluminum salts/alkoxides usually results in the formation of ametal oxide/hydroxide.Inthis regard, it is important to slow down its hydrolysis process to promote crystallization and simultaneously enable condensation occurs.R ecently,w eh ave applied organic ligands to delay the hydrolysis process of Ti IV ions through coordination interactions (denoted as coordination delayed hydrolysis (CDH)). [20][21][22][23][24] Therefore,w eb elieve the strategy can be used to understand the hydrolysis and condensation of Al III precursors,w hich remained relatively unexplored before. Considering the similar hydrolysis process between Ti IV and Al III ions,i ti sp redictable that the CDH strategy may bring an ew blueprint for constructing atomically-precise Almolecular architectures.…”

Coordination Assembly of the Water‐Soluble Ti4(embonate)6 Cages with Mn2+ Ions

“…Previously, we reported a water‐soluble Ti‐based tetrahedral cage with calixarene‐like coordination active vertices (Figure ), namely, [(Me 2 NH 2 ) 8 (Ti 4 L 6 )] ⋅ Guests (PTC‐101, L=embonate) . It is worth pointing out that compound PTC‐101 has been applied as the starting material to realize coordination assembly with different metal ions through two‐step reaction.…”

“…Previously, we reported a water-soluble Ti-based tetrahedral cage with calixarene-like coordination active vertices ( Figure 1), namely, [(Me 2 NH 2 ) 8 (Ti 4 L 6 )] · Guests (PTC-101, L = embonate). [37] It is worth pointing out that compound PTC-101 has been applied as the starting material to realize coordination assembly with different metal ions through two-step reaction. For example, by trapping different amounts of Co or Ln ions, the Ti 4 L 6 tetrahedra can be organized into various dimensional architectures, including Ti 4 L 6 -Co 3 cage (PTC-103), Ti 4 L 6 ÀLn 2 cage (PTC-104), Ti 4 L 6 ÀLn 2 chain (PTC-105) and three-dimensional (3D) Ti 4 L 6 ÀLn framework (PTC-106).…”