Polysulfonic acids and polysulfonates: Synthesis, structures, and properties

• Applicants: Professor Dr. Jens Christoffers; Professor Dr. Mathias Wickleder
• Subject Area: Solid State and Surface Chemistry, Material Synthesis ; Organic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2012 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 223676145

• Final Report Year: 2022

Final Report Abstract

Compared to the established and extensive knowledge about the synthesis of carboxylic acids, the number of synthetic protocols for related sulfonic acids is rather limited. In view of the so far unexplored potential of sulfonic acids for the preparation of coordination polymers (CPs) or metal-organic frameworks (MOFs), we have developed a number of reliable protocols for the synthesis of various sulfonic acids as part of the research project since 2009. With the completion of this project, a comprehensive library of various linker compounds is now available, which is intended to promote the development of a extensive coordination chemistry of oligosulfonates. As part of the second funding period, we have developed the synthesis of biphenyl mono- and disulfonic acids, which carry one or two additional perfluorobutyl or -hexyl chains. Such compounds should be suitable as amphiphilic linker molecules for CPs or MOFs. Furthermore, benzene mono- and disulfonic acids with a 4-pyridyl or 5-pyrimidyl residue were prepared. Herein, the nitrogen atom represents an additional donor function for the coordination of a metal center. The new acids have been used for the syntheses of polysulfonates with various metals. In many cases, crystalline material could be obtained and crystal structures have been determined. However, frequently crystallization is hampered, especially for acids with large scaffolds and those with fluorinated sidechains. We have started to transfer our experience also towards the synthesis of new carbonic acids. Furthermore, we started the investigation of polysulfonic acids with small scaffolds. For the carbonic acids we have obtained the racemic 1,3-allenedicarboxylic acid and their salts of lithium, sodium, rubidium and cesium as well as the thallium(I) were investigated. This structurally unique dicarboxylic acid possesses a 90°- torsion angle between the two carboxylate groups. For polysulfonates with small scaffolds the unique methanetetrasulfonate anion was obtained.

Publications

• "Biphenyl Sulfonic and Disulfonic Acids with Perfluorinated Alkyl Residues", Eur. J. Org. Chem. 2018, 5754–5462
  C. Kahrs, M. S. Wickleder, J. Christoffers
  
• "Pyridine and Pyrimidine Functionalized Benzene Sulfonic and Disulfonic Acids as New Linker Compounds for Coordination Polymers", Eur. J. Org. Chem. 2018, 6499–6509
  C. Kahrs, M. Schmidtmann, M. S. Wickleder, J. Christoffers
  
• "Carboxylate groups in a 90° arrangement: 1,3-Allenedicarboxylic Acid and its Alkali Metal and Thallium(I) Coordination Compounds", Eur. J. Inorg. Chem. 2019, 2781–2787
  C. Kahrs, M. Schmidtmann, M. S. Wickleder, J. Christoffers
  
• "Tripodal methanetrisulfonate ligands in the trinuclear complex {Ni3[CH(SO3)3]2(NMP)8}", Z. Naturforsch. B. 2019, 74, 27–31
  M. Gudenschwager, J. Christoffers, M. S. Wickleder
  
• "Synthesis of Aromatic and Aliphatic Di-, Tri- and Tetrasulfonic Acids", Synlett 2020, 31, 945–952
  J. Christoffers, M. S. Wickleder