Terminal tungsten pnictide complex formation through pnictaethynolate decarbonylation

Area of Science:

• Organometallic Chemistry
• Inorganic Chemistry

Background:

• Tungsten complexes are versatile in chemical synthesis.
• Formation of anionic terminal pnictide complexes is challenging.

Purpose of the Study:

• To develop a novel decarbonylative method for synthesizing anionic terminal phosphide and arsenide complexes.
• To explore the utility of tungsten(IV) tetrakis(2,6-diisopropylphenoxide) as a platform for pnictide complex formation.

Main Methods:

• Treatment of tungsten(IV) tetrakis(2,6-diisopropylphenoxide) with pnictaethynolate anions (cyanate, 2-phosphaethynolate, and 2-arsaethynolate).
• Isolation and characterization of the resulting phosphide and arsenide complexes.
• Measurement of NMR coupling constants (183W-15N, 183W-31P).
• Natural bond orbital (NBO) analysis to understand bonding.

Main Results:

• Successful decarbonylative formation of anionic terminal phosphide and arsenide complexes from cyanate (OCP-) and 2-arsaethynolate (OCAs-) anions, respectively.
• These represent the first examples of terminal phosphide and arsenide complex formation at a transition metal center using these precursors.
• The isolated complexes feature a tetragonal, all-oxygen ligand environment around the tungsten center.
• NMR coupling constants were measured and analyzed to determine s orbital character in bonding.

Conclusions:

• Tungsten(IV) tetrakis(2,6-diisopropylphenoxide) is an effective platform for synthesizing novel terminal pnictide complexes.
• This work expands the scope of transition metal-mediated pnictide chemistry.
• The study provides insights into the electronic structure and bonding of these unique complexes.