Date of Award

9-11-2019

Publication Type

Master Thesis

Degree Name

M.Sc.

Department

Chemistry and Biochemistry

Keywords

cocrystal, diselenadiazolyl, dithiadiazolyl, metal-organic framework, radical, supramolecular

Supervisor

Rawson, J.

Rights

info:eu-repo/semantics/openAccess

Abstract

Chapter 1 of this thesis provides an introduction to molecule-based materials chemistry and the interplay between structure and physical properties in main group radicals. An emphasis is placed on the importance of non-covalent interactions in providing control of the resultant solid-state architecture including the use of ‘host-guest’ chemistry within metal-organic frameworks and the identification of robust ‘supramolecular synthons’ for molecular self-assembly for single component systems or for molecular recognition in multi-component materials. Chapter 2 describes the inclusion chemistry of dithiadiazolyl (DTDA) radicals (and diselenadiazolyl (DSDA) radicals into the porous metal-organic framework MIL-53(Al) [Al(BDC)(OH)], where BDC = 1,4-benzenedicarboxylate)]. The structures and physical properties of these host-guest complexes are characterized through powder X-ray diffraction, EPR spectroscopy and SQUID magnetometry, thermal analysis (DSC and TGA) as well as mass spectrometry, IR spectroscopy and elemental analysis. Preliminary reactivity studies show that halogens can percolate into the channel structure leading to complete (Cl2 and Br2) or partial oxidation (I2) of the incorporated guest molecules. Chapter 3 identifies a new robust supramolecular synthon for radical-radical cocrystal formation. Cocrystallization of perfluoroaryl DTDA and DSDA radicals with the nitroxide radicals TEMPO and TEMPONE formed a series of nine 2:1 cocrystals of general formula [ArFCNEEN]2[TEMPO(NE)] which were characterized by X-ray diffraction and EPR spectroscopy, with all derivatives exhibited a common tetrafurcated E4···O-N interaction.

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