Ordered Vacancies and Their Chemistry in Metal–Organic Frameworks

Vacancies
are common in solid materials, but it remains a challenge
to introduce them at specific locations with controlled distributions.
Here we report the creation of ordered metal vacancies and linker
vacancies in a cubic metal–organic framework (MOF) based on
Zn­(II) and pyrazolecarboxylic acid by removing a quarter of the metal
ions and half of the linkers. The MOF with ordered vacancies shows
increased pore size, thus allowing large dye molecules to fit in the
pores. Furthermore, by filling the vacancies with new metals and new
linkers, eight new single-crystalline MOFs with multicomponents in
absolute order are introduced. The capability of performing stepwise
elimination and addition reactions systematically in extended solids
without destroying the structural integrity has generated complex
MOF structures which otherwise cannot be made.