Regensburg 2022 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 9: Thin Film Properties: Structure, Morphology and Composition (XRD, TEM, XPS, SIMS, RBS, AFM, ...) 3

DS 9.6: Vortrag

Dienstag, 6. September 2022, 10:45–11:00, H14

Temperature-dependent C-AFM measurements on rhodium paddle-wheel coordination polymers — Daniel Steinbach, Sophie Gersdorf, and •Florian Mertens — Institute of Physical Chemistry, TU Bergakademie Freiberg, Germany

To overcome one of the disadvantages of most coordination polymers and metal-organic frameworks being insulators, conjugated coordination polymers are investigated regarding their electrical conductivity. To obtain a potentially conductive system paddle-wheel structures with a documented metal-metal bond, here rhodium derivates, were linked via conjugated organic molecules like pyrazine. Coordination polymers of this type were first synthesized as bulk materials, characterized using XRD, TG-DSC and XPS and then deposited as coatings on gold surfaces. Subsequently, the topography of the deposited layers was determined. The morphological properties of the coatings were correlated with the properties of the basic coordination polymer components.

The conductivity was investigated via temperature-dependent C-AFM measurements. As expected no conductivity is measurable for coordination polymers containing acetates based paddle-wheels even if they are linked with a tridentate conjugated ligand. For the [Rh2(acam)4(pyz)]n (Hacam = acetamide) coordination polymer a strong temperature and field dependency of the conductivity was observed. From the corresponding measurements an arrhenius type activation energy of app. 0.3-0.4 eV was derived. In addition, various conduction mechanisms were discussed.