Unleashing phosphorus mononitride.

Area of Science:

• Inorganic Chemistry
• Organometallic Chemistry
• Astrochemistry

Background:

• The interstellar diatomic molecule, phosphorus mononitride (P≡N), is highly unstable under Earth conditions.
• The utility of P≡N for constructing elusive P-N π-bonded motifs is uncertain.

Purpose of the Study:

• To synthesize and characterize a metal-bound P≡N ligand.
• To explore the reactivity of the P≡N ligand in forming new P-N motifs.
• To investigate the electronic structure and bonding in metal-P≡N complexes.

Main Methods:

• Synthesis of a metal-bound P≡N ligand using Na(OCP) and an osmium nitride complex.
• Quantum chemical calculations to determine electronic structure.
• X-ray absorption spectroscopy for structural analysis.
• Reactions with elemental sulfur and chlorination to probe reactivity.
• [3+2] cycloaddition reactions with azide.

Main Results:

• Formation of a metal-bound P≡N ligand with a cumulenic [Os^IV=N=P] electronic structure.
• Observation of orthogonal Os=N and N=P π-bonding.
• Transformation of the P≡N ligand to a trigonal planar [NPS₂]^2- motif upon reaction with sulfur.
• Conversion of the P≡N ligand to a bent [NPCl]^- group coordinated to Os^III upon chlorination.
• Synthesis of an aromatic interpnictide, [PN₄]^-, via cycloaddition.

Conclusions:

• Demonstration of the synthesis of a metal-bound P≡N ligand.
• Unveiling of the unique electronic structure and π-bonding within the complex.
• Showcasing the divergent reactivity of the P≡N ligand, leading to novel P-N motifs.
• Paving the way for the construction of long-sought P-N multiple-bonded archetypes.