Polyimido sulfur(VI) phosphanyl ligand in metal complexation

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Main Group Chemistry

Background:

• The development of novel ligands with diverse donor sites is crucial for advancing coordination chemistry.
• Imido ligands offer unique electronic and steric properties for metal complexation.
• The [Ph2PCH2S(NtBu)3](-) anion presents a novel scaffold with multiple potential coordination sites.

Purpose of the Study:

• To synthesize and characterize new metal complexes utilizing the [Ph2PCH2S(NtBu)3](-) ligand.
• To investigate the coordination behavior of this ligand with transition metals.
• To explore the structural and electronic properties of the resulting complexes.

Main Methods:

• Synthesis of the lithiated precursor [(tmeda)Li{(NtBu)3SCH2PPh2}].
• Transmetalation reactions with various transition metal salts (Mn, Ni, Zn).
• Single-crystal X-ray diffraction for structural characterization of the synthesized complexes.

Main Results:

• Successful synthesis of transition metal complexes [M{(NtBu)3SCH2PPh2}2] (M=Mn, Ni, Zn).
• Structural characterization revealed SN2 chelation, with the sulfur atom and two imido nitrogens coordinating to the metal center.
• The phosphorus atom remained uncoordinated, and the third imido group exhibited a specific orientation.

Conclusions:

• The [Ph2PCH2S(NtBu)3](-) ligand effectively coordinates to transition metals through its imido nitrogen atoms and sulfur atom.
• The observed SN2 chelation mode highlights the ligand's versatility in coordination chemistry.
• The structural findings provide insights into the coordination preferences and steric effects of this novel ligand system.