A high-pressure polymorph of phosphorus nitride imide

Area of Science:

• Solid-state chemistry
• Materials science
• Crystallography

Background:

• Phosphorus nitride imide (PN(NH)) is structurally analogous to silica (SiO2).
• Only one polymorph of PN(NH) has been previously documented.
• A greater structural diversity is anticipated due to its isosteric relationship with SiO2.

Purpose of the Study:

• To synthesize and characterize a new polymorph of phosphorus nitride imide.
• To investigate the structural properties of PN(NH) under high-pressure conditions.
• To explore the potential for diverse condensed phosphorus nitride structures.

Main Methods:

• High-pressure synthesis using a multianvil apparatus.
• Crystal growth facilitated by NH4Cl mineralizer.
• Structural elucidation via single-crystal X-ray diffraction.
• Structure confirmation using FTIR and solid-state NMR spectroscopy ((31)P and (1)H).

Main Results:

• The first high-pressure polymorph of phosphorus nitride imide, designated β-PN(NH), was successfully synthesized.
• Single crystals of β-PN(NH) were obtained, enabling complete structural determination.
• The synthesized structure represents a highly condensed form of phosphorus nitride.

Conclusions:

• The discovery of β-PN(NH) expands the known structural landscape of phosphorus nitride imides.
• Further high-pressure/high-temperature studies may yield novel polymorphs with varied phosphorus coordination.
• The structural variety of PN(NH) could potentially rival or surpass that of SiO2.