In the past decades, polyhedral coordination cages have been attracting growing research attention due to their aesthetically appealing structures and wide applications in various fields. However, most of the research interests in this field have been devoted to the construction of discrete cages and their further assembly into advanced supramolecular materials has been less developed. Moreover, metal-organic cages based on the earth abundant Ti are still relatively less, which might be found to have potential applications as photoactive materials.
Recently, Team of Synthetic Inorganic Chemistry led by Prof. ZHANG Jian and Prof. ZHANG Lei at the State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter (FJIRSM) of the Chinese Academy of Sciences(CAS), has successfully prepared a tetrahedral Ti4L6 cage with calixarene-like coordination active vertices, which can be readily assembled by transition and lanthanide metal ions and also presents efficient and selective photocatalytic activities. The study has been published in J. Am. Chem. Soc..
The obtained Ti4L6 cage is featured by high solubility and stability in H2O and DMF/H2O solution. In addition with its calixarene-like coordination active vertices, this Ti4L6 cage shows interesting stepwise assembly function with other metal ions. Through trapping different amounts of Co or Ln ions, it can be organized into Ti4L6-Co3 cage, Ti4L6-Ln2 cage, Ti4L6-Ln2 chain and three-dimensional (3D) Ti4L6-Ln framework.
More remarkably, the Ti4L6 cage also shows selective and efficient homogeneous photodecomposition of acid blue 93 (AB-93) and alkali blue 4B (AB-4B) driven by visible light, which might be attributed to N-H×××O hydrogen bonding between the calixarene-like oxygen vertices of the Ti4L6 cage and the dye molecules.
This work provides a Ti4L6 cage not only possesses interesting coordination assembly function, but also shows important photoactive applications.
Illustration of the solubility and stepwise assembly of the Ti4L6 cage (Image by Prof. ZHANG’s Group)
Contact:
Prof. ZHANG Jian
Fujian Institute of Research on the Structure of Matter
Chinese Academy of Sciences
Email: zhj@fjirsm.ac.cn
