Molecular Phosphide Complexes of Zirconium.

Area of Science:

• Organometallic Chemistry
• Inorganic Chemistry
• Coordination Chemistry

Background:

• Molecular zirconium phosphides are exceptionally rare in chemical literature.
• No known examples feature a one-coordinated, terminal triple-bonded phosphorus atom.

Purpose of the Study:

• To synthesize and characterize a novel, isolable zirconium phosphide complex.
• To investigate the properties of a terminal triple-bonded phosphorus atom coordinated to zirconium.

Main Methods:

• Synthesis of a cyclometalated Zr-hydride complex from Zr precursors.
• Reaction of the Zr-hydride with sodium dihydrogen phosphide (NaPH2).
• Structural and spectroscopic characterization (X-ray diffraction, NMR spectroscopy) of the resulting complexes.

Main Results:

• Isolation of a stable Zr phosphide complex, [(PN)2Zr≡P{μ2-Na(OEt2)}]2, featuring a Zr≡P triple bond.
• Characterization of related Zr(IV) complexes and intermediates.
• Demonstration of exceptionally short Zr≡P bond lengths and characteristic downfield 31P NMR resonances.

Conclusions:

• The study reports the first isolable molecular zirconium phosphide with a terminal triple-bonded phosphorus atom.
• The synthesized complexes provide new insights into metal-phosphorus multiple bonding.
• The Zr≡P motif can be further stabilized by coordination with other metal ions.