Universität zu Köln

Mertens, Alisha (2024). Studies on Halogenated Methane Sulphonates and Polysulphonated Methane Derivatives. PhD thesis, Universität zu Köln.

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Abstract

Derivatives of methanesulphonic acid are assembled by formal substitution of the hydrogen atoms at the methyl function on CH3SO3H. Substitution of H with halogens such as Cl and Br deliver the halogenated methanesulphonic acids Cl3CSO3H and Br3CSO3H. Trichloromethanesulphonate “trichlate” and tribromomethanesulphonate “tribrate” salts are characterised by X-ray diffraction for structure determination. Experimentally trichlate compounds are obtained in a three-step reaction mechanism starting from relatively cheap starting materials CS2 and chlorine gas. Comparable to triflate salts, the trichlate compounds are prone to build layered structures due to the amphiphilic character of the anion. Additionally, the crystal structures frequently entail water, which has a high share in the saturation of the coordination sphere of the respective cation. Thus, the weak coordinating character of [Cl3CSO3]− results in the structures [Fe(DMSO)6][Cl3CSO3]3 and [Co(H2O)6][Cl3CSO3]2, where the coordination sphere around the cation is entirely built by solvent molecules. The trichlate anion is stable up to temperatures of roughly 600 K. Bromination reaction of aromatic methanesulphonates, such as phenyl methanesulphonate with a freshly prepared hypobromite solution followed by cleavage of the aromatic ring generates tribrate compounds. Crystal structures of lithium and potassium tribrates show similar characteristics as their smaller siblings. The tribrate anion has a staggered conformation, crystal structures contain layers and crystal water, that has a high impact on the coordination sphere of the respective cation. Formal substitution of H with SO3H unities at the methyl group in CH3SO3H delivers polysulphonic acids. Analysis of solid state structures of lithium, caesium and potassium methanedisulphonate show an isotypy to lithium and potassium disulphate. Salts displaying the [CH(SO3)3]3− anion show a diversity in their crystal structures, that does not reveal clear trends or isostructural relations.

Item Type:	Thesis (PhD thesis)
Creators:	Creators Email ORCID ORCID Put Code Mertens, Alisha UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-726331
Date:	2024
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Chemistry > Institute of Inorganic Chemistry
Subjects:	Chemistry and allied sciences
Uncontrolled Keywords:	Keywords Language Trichloromethansulfonate English Weakly Coordinating Anions English Superacids English
Date of oral exam:	10 April 2024
Referee:	Name Academic Title Wickleder, Mathias S. Prof. Dr.
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/72633