Impact of molecular symmetry on crystallization pathways in highly supersaturated KH<sub>2</sub>PO<sub>4</sub> solutions.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38600081.
- Also identified by DOI 10.1038/s41467-024-47503-1 and PMC identifier 11006877.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Solute structure and its evolution in supersaturated aqueous solutions are key clues to understand Ostwald's step rule. Here, we measure the structural evolution of solute molecules in highly supersaturated solutions of KH2PO4 (KDP) and NH4H2PO4 (ADP) using a combination of electrostatic levitation and synchrotron X-ray scattering. The measurement reveals the existence of a solution-solution transition in KDP solution, caused by changing molecular symmetries and structural evolution of the solution with supersaturation. Moreover, we find that the molecular symmetry of H2PO4- impacts on phase selection. These findings manifest that molecular symmetry and its structural evolution can govern the crystallization pathways in aqueous solutions, explaining the microscopic origin of Ostwald's step rule.