Computational design of gallium imides for methane activation

Area of Science:

• Organometallic Chemistry
• Computational Chemistry
• Catalysis

Background:

• NacNac gallium imide complexes can cleave unactivated sp3 C-H bonds.
• Methane activation remains a significant challenge in homogeneous catalysis.
• Computational modeling offers a pathway to design improved catalysts.

Purpose of the Study:

• To computationally modify NacNac gallium imide for efficient methane activation.
• To explore strategies for reducing the methane activation energy barrier.
• To identify suitable modified gallium imide structures for alkane functionalization.

Main Methods:

• Density functional theory (DFT) calculations were employed.
• Systematic modification of substituents around the gallium center was investigated.
• The effect of pre-straining the gallium imide framework was analyzed.
• Strategies to prevent catalyst dimerization were evaluated.

Main Results:

• Changing substituents reduced the methane activation barrier from 123 kJ mol⁻¹ to 93 kJ mol⁻¹.
• Pre-straining the gallium imide further lowered the activation barrier to 62 kJ mol⁻¹.
• Bulky groups were identified to prevent dimerization without impacting the activation barrier.
• Several modified NacNac gallium imides demonstrated viability for methane and alkane activation.

Conclusions:

• Computational modeling successfully identified modified NacNac gallium imides suitable for methane activation.
• Substituent modification and pre-straining are effective strategies for lowering reaction barriers.
• Designed gallium imide complexes show promise for homogeneous alkane functionalization.