The structure-directing role of the inorganic secondary building unit (SBU) is key for determining the topology of metal-organic frameworks (MOFs). Here we show that organic building units relying on strong π interactions that are energetically competitive with the formation of common inorganic SBUs can also play a role in defining the topology. We demonstrate the importance of the organic SBU in the formation of Mg2H6(H3O)(TTFTB)3 (MIT-25), a mesoporous MOF with the new ssp topology. A delocalized electronic hole is critical in the stabilization of the TTF triad organic SBUs and exemplifies a design principle for future MOF synthesis.
Bibliographical noteFunding Information:
All experimental work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences (DESC0006937). M.D. gratefully acknowledges early career support from the Sloan Foundation, the Research Corporation for Science Advancement (Cottrell Scholar), and the Dreyfus Foundation. S.S.P. was partially supported by a National Science Foundation Graduate Research Fellowship (1122374). A.J.F. was supported by Bruker. All of the EPR experiments were carried out at the EPSRC National EPR Facility and Service, University of Manchester, U.K.. A.W. was supported by the ERC (277757). S.S.P. thanks M. Korzyński for providing H4TBAPy. We thank Dr. P. Müller and Dr. J. Becker for assistance with crystallography and Prof. O. Yaghi for valuable discussions. Computational work was enabled by access to XSEDE, which is supported by NSF (ACI-1053575).
© 2017 American Chemical Society.