Semi-bridging σ-silyls as Z-type ligands

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Silicon Chemistry

Background:

• Zerovalent group 10 metals (Ni, Pd, Pt) are crucial in catalysis.
• Silicon-containing ligands offer unique coordination possibilities.
• Bimetallic complexes can exhibit novel electronic and structural properties.

Purpose of the Study:

• To synthesize and characterize novel homoleptic bimetallic complexes.
• To investigate the structural and electronic properties of these complexes.
• To explore the bonding interactions within the M-M bond bridged by silyl groups.

Main Methods:

• Reaction of SiHPh(NCH2PPh2)2C6H4-1,2 with zerovalent group 10 reagents.
• Isolation and characterization of homoleptic bimetallic complexes [M2{μ-κ3-Si,P,P'-SiPh(CH2PPh2)2C6H4}2].
• Spectroscopic and crystallographic analysis to determine structural and bonding features.

Main Results:

• Successful synthesis of homoleptic bimetallic complexes [M2{μ-κ3-Si,P,P'-SiPh(CH2PPh2)2C6H4}2] for M = Ni, Pd, Pt.
• Observation of an M-M bond unsymmetrically bridged by two σ-silyl groups.
• Increasing asymmetry of the M2Si2 core observed from Ni to Pt.

Conclusions:

• The synthesized complexes exhibit an unusual M-M bond bridged by silyl ligands.
• The observed asymmetry is explained by a bonding model involving a 'Z-type' silicon center.
• This work expands the understanding of bonding in low-valent transition metal silyl complexes.