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Updated: Apr 5, 2026

Sulfate Separation by Selective Crystallization with a Bis-iminoguanidinium Ligand
Published on: September 8, 2016
Aqueous Sulfate Separation by Crystallization of Sulfate-Water Clusters
Radu Custelcean1, Neil J Williams2,3, Charles A Seipp2,4
1Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6119 (USA). custelceanr@ornl.gov.
Abstract:
An effective approach to sulfate separation from aqueous solutions is based on the crystallization of extended [SO4(H2O)5(2-)]n sulfate-water clusters with a bis(guanidinium) ligand. The ligand was generated in situ by hydrazone condensation in water, thereby bypassing the need for elaborate syntheses, tedious purifications, and organic solvents. Crystallization of sulfate-water clusters represents an alternative approach to the now established sulfate separation strategies that involve encapsulation of the "naked" anion.
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