How metallylenes activate small molecules.

Area of Science:

• Computational Chemistry
• Organometallic Chemistry
• Catalysis

Background:

• Metallylenes are versatile compounds with potential applications in catalysis.
• Understanding the factors governing dihydrogen activation is crucial for developing new catalytic processes.

Purpose of the Study:

• To investigate the activation of dihydrogen by metallylenes using relativistic density functional theory (DFT).
• To elucidate the electronic and steric factors influencing metallylene reactivity.
• To design novel metallylenes for efficient small molecule activation and hydrogenation reactions.

Main Methods:

• Relativistic density functional theory (DFT) calculations.
• Activation strain analysis.
• Kohn-Sham molecular orbital analysis.

Main Results:

• Reactivity of metallylenes in dihydrogen activation decreases down Group 14 due to reduced back-donation.
• Ligand variation from nitrogen to phosphorus to arsenic enhances H2 activation via reduced steric repulsion and activation strain.
• Designer metallylenes efficiently activate small molecules (HCN, CO2, H2, NH3) and hydrogenate unsaturated hydrocarbons.

Conclusions:

• The study provides a quantitative understanding of reactivity trends in metallylene-mediated dihydrogen activation.
• Rational design of metallylenes, considering both the Group 14 atom and ligand properties, is key for optimizing catalytic activity.
• Developed designer metallylenes show promise for activating small molecules and catalyzing hydrogenation reactions, opening new avenues in synthetic chemistry.