Fabrication of zinc-dicarboxylate- and zinc-pyrazolate-carboxylate-framework thin films through vapour–solid deposition

Abstract

Fabrication of three-dimensional metal-organic framework (MOF) thin films has been investigated for the first time through the conversion of a ZnO layer via a pure vapour–solid deposition reaction at ambient pressure. The fabrication of MOF thin films with a dicarboxylate linker, (DMA)₂[Zn₃(bdc)₄] (1) (bdc = 1,4-benzenedicarboxylate), and a carboxy-pyrazolate linker, [Zn₄O(dmcapz)₆] (2) (dmcapz = 3,5-dimethyl-4-carboxypyrazole), involves the deposition of the linker and/or the preparation of a composite film preliminarily and its subsequent conversion into a MOF film using closed cell thermal treatment. Furthermore, it was possible to isolate thin films with a MOF-5 isotype structure grown along the [110] direction, using a carboxy-pyrazolate linker. This was achieved just by the direct reaction of the ZnO film and the organic linker vapors, employing a simple route that demonstrates the feasibility of MOF thin film fabrication using inexpensive routes at ambient pressure.