Related Experiment Video
Updated: Aug 12, 2025

Sulfate Separation by Selective Crystallization with a Bis-iminoguanidinium Ligand
Published on: September 8, 2016
Selective Removal of Sulfate from Water by Precipitation with a Rigid Bis-amidinium Compound
Nikki A Tzioumis1, Duncan A Cullen2, Katrina A Jolliffe1
1Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, School of Chemistry, The University of Sydney, Sydney, NSW, 2006, Australia.
Abstract:
A simple, readily prepared biphenyl bis-amidinium compound (1⋅Cl2 ) is able to selectively precipitate sulfate from water. The precipitant is effective at concentrations as low as 1 mM and shows complete selectivity against monovalent anions, and high selectivity even against CO3 2- and HPO4 2- . It is highly effective (>90 % sulfate removed) in both seawater and highly acidic conditions relevant to mining waste-streams. X-ray crystallography reveals that 1⋅SO4 forms a tightly packed, anhydrous, structure where each sulfate anion receives eight hydrogen bonds from amidinium N-H hydrogen bond donors.
Related Concept Videos
Precipitation and Co-precipitation
Precipitation of Ions
The equation that describes the equilibrium between solid calcium carbonate and its solvated ions is:
Factors Affecting Solubility
Colloidal precipitates
Coagulation
Qualitative Analysis
For instance, group IV...

