An H-Substituted Rhodium Silylene

Area of Science:

• Organometallic Chemistry
• Rhodium Complexes
• Silylene Chemistry

Background:

• Organometallic rhodium(I) complexes display diverse reactivity.
• Silylenes are silicon analogues of carbenes, with unique bonding properties.
• Understanding silylene formation and characterization is crucial for catalysis and materials science.

Purpose of the Study:

• To investigate the reactivity of rhodium(I) complexes with hydrosilanes.
• To isolate and characterize novel neutral rhodium silylene complexes.
• To elucidate the structural and electronic properties of the resulting silylenes.

Main Methods:

• Addition reactions of hydrosilanes (PhRSiH2) to rhodium(I) complexes ((iPrNNN)Rh(COE) and (iPrNNN)Rh(CO)).
• Isolation and characterization of rhodium(III) silyl hydride and rhodium(I) silylene complexes.
• Multinuclear NMR spectroscopy, X-ray crystallography, and Density Functional Theory (DFT) computations.

Main Results:

• Isolation of neutral rhodium(I) silylenes (iPrNNN)(CO)Rh=SiRPh (R=H, Ph).
• Characterization of short Rh-Si bonds (2.262(1) Å and 2.2702(7) Å) in the silylene complexes.
• Observation of a change in the (iPrNNN) ligand bonding mode and loss of H2 during the reaction.

Conclusions:

• Divergent reactivity of rhodium(I) complexes with hydrosilanes leads to neutral silylenes.
• The isolated rhodium silylenes possess well-defined structures with short Rh-Si bonds.
• Deuterium labeling confirmed the loss of H2, providing insights into the reaction mechanism.