On-surface molecular frameworks – synthesis, properties and function
Place: conference hall, IMDEA Nanociencia.
Abstract:
Crystalline and porous molecular framework materials with specific encoded properties hold promise as a novel, highly tunable, functional platform.[1] Through the concepts of reticular chemistry, numerous two‐ and three‐dimensional molecular frameworks with diverse structural, optical, and electrical properties are in reach. On-surface deposition of molecular framework coatings is crucial for their utilization as active layers in advanced device-based applications, including separation, sensing and optoelectronics. In addition to the variable backbone properties, gaining control over the molecular framework film morphology is of critical importance for achieving the intended functionality.[2] In this presentation, I will first discuss new insights into the crystallization process of 2D molecular frameworks.[3] In the following, the on-surface synthesis of metal- and covalent-organic frameworks (MOFs and COFs) as films and deposits is presented. For COFs, the in-situ thin film synthesis approach will be discussed and presented as a reliable and well-established methodology for the synthesis of COF thin films. Here, the synthesis of novel layered thiophene-extended benzotrithiophene-based (BTT) COFs as highly oriented and crystalline thin films and their respective directional electrical conductivity will be illustrated.[4] In addition, thienothiophene (TT) isomer doping of a COF scaffold will be presented as an efficient tool for band-gap engineering of ordered organic solids in the form of bulk and films.[5] For MOFs, vapor-assisted conversion (VAC) will be presented as a versatile method for the deposition of thin films of both 3D and 2D MOFs, particularly for the metal (Ni2+, Co2+, Cu2+) catecholate M-CAT-1 series.[6] The films obtained by VAC feature thicknesses in the nanometer scale with a particular morphology, topography and roughness. Subsequently, M-CAT-1 films are implemented as active layers into devices to be tested for a variety of applications ranging from (opto)electronics to wastewater treatment.[7, 8] For the latter, ultrahigh flux separation of oily pollutants from water is achieved with a filter mesh decorated with MOF nanoscale architectures.
References
[1] A. Mähringer, D. D. Medina, Nat. Chem., 2020, 12, 985–987.
[2] D. D. Medina, T. Sick, et al. Adv. Energy Mater., 2017, 7, 1700387.
[3] C. Gruber, L. Frey, et al. Nature, 2024, 630, 872–877.
[4] L. Frey, J. F. Pöhls, et al. Adv. Funct. Mater., 2022, 32, 2205949.
[5] R. Guntermann, L. Frey, et al. J. Am. Chem. Soc., 2024, 146, 23, 15869.
[6] (a) E. Virmani, J. M. Rotter, et al. J. Am. Chem. Soc., 2018, 140, 4812–4819. (b) P. I. Scheurle, A. Mähringer, et al. Chem. Mater., 2021, 33, 15, 5896–5904.
[7] A. Mähringer, A. C. Jakowetz, et al. ACS Nano., 2019, 13, 6711–6719.
[8] A. Mähringer, M. Hennemann, et al. Angew. Chem. Int. Ed., 2021, 60, 5519–5526.