[P(3)Se(7)](3-): a phosphorus-rich square-ring selenophosphate

Area of Science:

• Inorganic Chemistry
• Solid-State Chemistry
• Materials Science

Background:

• Phosphorus-selenium compounds are of interest due to their diverse structures and potential applications.
• The synthesis and characterization of novel anionic species provide insights into chemical bonding and reactivity.

Purpose of the Study:

• To synthesize and characterize a new cesium phosphorus selenide compound.
• To investigate the structural and electronic properties of the novel [P(3)Se(7)](3-) anion.

Main Methods:

• Single-crystal X-ray diffraction for structural determination.
• Electronic absorption, Raman, Fourier transform infrared (FTIR), and solid-state 31P Nuclear Magnetic Resonance (NMR) spectroscopy for characterization.

Main Results:

• The new compound Cs(10)P(8)Se(20) was synthesized and its crystal structure determined in the orthorhombic space group Pnnm.
• The structure features the heterotetracyclic [P(3)Se(7)](3-) anion with a P-P-P unit and formally P(3+) and P(4+) centers, co-crystallized with a [P(2)Se(6)](4-) anion.
• Spectroscopic studies provided insights into the vibrational and electronic properties of the compound.

Conclusions:

• Cs(10)P(8)Se(20) represents a new material containing a unique phosphorus-rich heterotetracyclic anion.
• The mixed-valence nature of phosphorus in the [P(3)Se(7)](3-) anion is a significant finding.
• The reported spectroscopic data contribute to the understanding of bonding and structure in phosphorus-selenium systems.