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Updated: May 9, 2026

Synthetic Methodology for Asymmetric Ferrocene Derived Bio-conjugate Systems via Solid Phase Resin-based Methodology
Published on: March 12, 2015
Pincher ferrocene-derived cation carboxylate ion pairs in aqueous DMSO
Christie L Beck1, Stephen A Berg, Arthur H Winter
12101d Hach Hall. Department of Chemistry, Ames, IA 50014, USA. winter@iastate.edu.
Abstract:
Pincher cationic ferrocene hosts for carboxylate ion guests were synthesized and the binding constants were determined by NMR or UV-Vis titrations. These (di)cationic hosts form tight complexes with benzoate or acetate even in competitive aqueous DMSO solvent. A bis(acylguanidinium) ferrocene dication achieves a remarkable Ka of ~10(6) M(-1) to acetate in 9 : 1 DMSO-H2O and a Ka of 850 M(-1) in neat D2O, one of the highest association constants known for a carboxylate complex exploiting only electrostatic interactions in neat water. DFT computations of the binding enthalpy are in good agreement with the experimentally determined association constants. The ferrocene backbone used in these pincher complexes may prove to be a useful semi-flexible scaffold for redox detectable/switchable self-assemblies in aqueous solutions.
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