phd-2021

Radical architectures in two dimensions

Technological progress pillars on the study and discovery of materials. Two-dimensional materials, such as atomic layers of graphene, chromium triiodide, and metal disulfides offer a plethora of extraordinary properties which are not paralleled in 3D materials. Nonetheless, their simple chemical nature leaves little possibility for optimization of their properties. Metal-organic framework (MOF) chemistry offers a route for the design of new materials, a modular approach using inorganic metal ion nodes and organic molecular spacers to build rigid networks. Notably, in combining the vast chemistry of the two areas, inorganic and organic chemistry, limitless opportunities for chemical modifications and the modulation of the physical properties become accessible. MOF materials can be designed as 3D crystalline materials with strong chemical bonding in 2D and weak bonding forces in the third dimension, hence, suggesting the possibility to design layered MOFs for the generation of new 2D materials through a top-down approach.

In this study, MOF chemistry is used for the design and synthesis of new 2D materials. The presented work is based on inorganic synthesis combined with a range of physical characterization techniques. Long-standing concepts in inorganic chemistry have been used to design new MOF architectures, some of which are ligand-field splitting, ligand mixed-valency on the basis of ligand radicals, the particular chemistry of 4f orbitals, and π back donation.

An emphasis is placed on synthesizing new materials with magnetic and conducting properties combined in the same material, as such multifunctionality is in demand for advancing technologies. For instance, modulating the conducting properties by controlling the magnetic structure with an outer magnetic field is used in magnetic data storage technologies. In addition, the design of materials with complex geometric arrangements is explored, as such geometrically frustrated structures entail rich physical properties, magnetic and optical, that could pave the way for new technological applications. Thirdly, a new approach to the synthesis of MOFs containing pore channels and metals in their zeroth oxidation state is presented. Zerovalent metals are part of different catalytic reactions, such as the Fischer-Tropsch and Water Gas Shift reaction. Their introduction into MOFs paves the way for an investigation of their use in catalytic applications.

 

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Supervisors

Kasper S. Pederse

Susanne  Mossin

 

Funded by

VILLUM Young  Investigator