title: Nanoporous designer solids with huge lattice constant gradients: multiheteroepitaxy of metal-organic frameworks.
abstract: We demonstrate the realization of hierarchically organized MOF (metal-organic framework) multilayer systems with pronounced differences in the size of the nanoscale pores. Unusually large values for the lattice constant mismatch at the MOF-MOF heterojunctions are made possible by a particular liquid-phase epitaxy process. The multiheteroepitaxy is demonstrated for the isoreticular SURMOF-2 series [ Liu et al. Sci. Rep. 2012 , 2 , 921 ] by fabricating trilayer systems with lattice constants of 1.12, 1.34, and 1.55 nm. Despite these large (20%) lattice mismatches, highly crystalline, oriented multilayers were obtained. A thorough theoretical analysis of the MOF-on-MOF heterojunction structure and energetics allows us to identify the two main reasons for this unexpected tolerance of large lattice mismatch: the healing of vacancies with acetate groups and the low elastic constant of MOF materials.
authors: Karlsruhe Institute of Technology, Institute of Functional Interfaces (IFG) , Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors: Zhengbang
authors: Z
authors: Wang
authors: Jinxuan
authors: J
authors: Liu
authors: Binit
authors: B
authors: Lukose
authors: Zhigang
authors: Z
authors: Gu
authors: Peter G
authors: PG
authors: Weidler
authors: Hartmut
authors: H
authors: Gliemann
authors: Thomas
authors: T
authors: Heine
authors: Christof
authors: C
authors: Wöll