Related Experiment Video
Updated: Jun 28, 2025

Optimization of Crystal Growth for Neutron Macromolecular Crystallography
Published on: March 13, 2021
Impact of molecular symmetry on crystallization pathways in highly supersaturated KH2PO4 solutions
Yong Chan Cho1, Sooheyong Lee1,2, Lei Wang1
1Frontier of Extreme Physics, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea.
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.
More Related Videos
06:35Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
09:52Optimizing the Growth of Endothiapepsin Crystals for Serial Crystallography Experiments
Published on: February 4, 2021
Related Concept Videos
Crystal Growth: Principles of Crystallization
Initiating crystallization involves manipulating the concentration of the solute and the temperature of the solution. Since crystal growth occurs when the ratio of concentration and solubility of the solute in the solvent...
Recrystallization: Solid–Solution Equilibria
Solution Equilibrium and Saturation
Molecular and Ionic Solids
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Polymer Classification: Crystallinity
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Precipitation Processes