Visible-light driven H₂ reductive elimination unlocks reactivity in polyhydrido niobium iridium clusters

Area of Science:

• Organometallic Chemistry
• Inorganic Chemistry
• Photochemistry

Background:

• Heterobimetallic complexes are of significant interest due to their unique bonding and reactivity.
• Polyhydrido complexes offer versatile platforms for exploring novel chemical transformations.

Purpose of the Study:

• To synthesize and characterize novel polyhydrido niobium-iridium heterobimetallic clusters.
• To investigate the photochemical reactivity of these complexes and compare it with tantalum analogues.
• To explore the substitution reactivity unlocked by photochemical transformations.

Main Methods:

• Synthesis of heterobimetallic complexes using Cp*IrH4 reagent.
• Characterization using spectroscopic and analytical techniques.
• Photochemical irradiation studies with visible light (>400 nm).

Main Results:

• Successful synthesis of polyhydrido niobium-iridium heterobimetallic clusters.
• Observed significantly short Ir-Nb intermetallic distances, suggesting multiple bonding.
• Photochemical transformation via dihydrogen elimination upon irradiation.
• Demonstrated unique photochemical reactivity compared to tantalum analogues.
• Unlocked substitution reactivity at the dimethylamido ligand post-photolysis.

Conclusions:

• The synthesized niobium-iridium complexes exhibit unique bonding and photochemical properties.
• Photochemical activation provides a pathway to generate highly reactive species with short Nb-Ir interactions.
• This study highlights a divergence in group-5 reactivity and offers new avenues for organometallic synthesis.