A Comparative Study of a High-Pressure Polymorph of I₂O₅ and its Ambient-Pressure Modification

Area of Science:

• Solid State Chemistry
• High-Pressure Materials Science
• Crystallography

Background:

• Iodine pentoxide (I₂O₅) is a key compound in various chemical applications.
• Understanding its structural behavior under pressure is crucial for materials science.

Purpose of the Study:

• To synthesize and characterize a new high-pressure polymorph of iodine pentoxide.
• To investigate the structural phase transition from the ambient-pressure form to the high-pressure form.

Main Methods:

• High-pressure/high-temperature synthesis using a Walker-type multianvil device.
• Single-crystal and powder X-ray diffraction for structural determination.
• Density Functional Theory (DFT) calculations to study phase transitions.

Main Results:

• A new monoclinic phase of I₂O₅ (HP-I₂O₅) was successfully synthesized at 8 GPa and 250 °C.
• The crystal structure was determined with space group P2₁/c and specific unit cell parameters.
• Phase transition behavior was explored using X-ray diffraction and DFT calculations.

Conclusions:

• The synthesis of HP-I₂O₅ reveals a new structural modification under high pressure.
• The study provides insights into the pressure-induced phase transition of iodine pentoxide.
• This work contributes to the field of high-pressure inorganic chemistry and materials science.