The ultimate goal is to arrange chemical functionalities along the backbone of the material the way we want, exactly as Prof. Feynman foresaw. If we could develop strategies to control exactly both the chemical nature and the location of the incorporated functional groups, we could synthesise materials of the future, where properties are determined not only by the chemical composition but more by the spatial composition.
There are two ways to endow a MOF material with internal-surface functionalities. The first approach involves the modification of one of the MOF building blocks in a way that it carries the functionality of interest throughout the MOF synthesis(Figure, left). The second approach consists of synthesizing the MOF structure, then chemically transforming the pre-synthesized MOF in a subsequent series of reactions called post-synthetic modifications (PSM, Figure, right).
Hereby, one of our major focus is to develop novel functionalization strategies and evaluate their relative usefulness.
Recently we expanded the scope of mixed-linker MOFs (two or more non-functionalized organic building blocks that can be precisely incorporated into a MOF scaffold with predetermined structural topologies) to include a subset of multivariate MOFs characterized by different functionalities in each set of linkers. This strategy could lead to a better understanding of the relationship between functionality, arrangement, and performance of multivariate MOF materials.
Relevant publications:
W. Schrimpf, J. Jiang, Z. Ji, P. Hirschle, D. C. Lamb, O. M. Yaghi,* S. Wuttke,* Chemical Diversity in a Metal-Organic Framework, Nature Commun. 2018, 9:1647. (DOI: 10.1038/s41467-018-04050-w)
C. Dietl, H. Hintz, B. Rühle, J. S. Günne, H. Langhals, S. Wuttke,* Switch-on fluorescence of a perylene dye functionalized metal-organic framework via post-synthetic modification, Chem. Eur. J. 2015, 10714-10720. (DOI : 10.1002/chem.201406157)
H. Hintz, S. Wuttke,* Solvent-Free and Time Effcient Postsynthetic Modification of Amino-Tagged Metal-Organic Frameworks with Carboxylic Acid Derivatives, Chem. Mater. 2014, 26, 6722-6728. (DOI : 10.1021/cm502920f)
H. Hintz, S. Wuttke,* Post synthetic modification of an amino-tagged MOF using peptide coupling reagents : a comparative study, Chem. Commun. 2014, 78, 11424–11424. (DOI : 10.1039/C4CC90357A)
S. Wuttke,* C. Dietel, F. M. Hinterholzinger, H. Hintz, H. Langhals, T. Bein, Turn-on fluorescence triggered by selective internal dye replacement in MOFs, Chem. Commun. 2014, 50, 3599–3601. (DOI : 10.1039/C3CC46591H)