The Bonding Situation in Metalated Ylides.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Organometallic Chemistry

Background:

• Metalated ylides and neutral bisylides are important classes of compounds.
• Understanding their electronic structure is crucial for predicting reactivity and properties.

Purpose of the Study:

• To investigate the electronic structure of metalated ylides compared to their neutral bisylide analogues.
• To analyze the impact of ligand nature and charge on the bonding and electronic properties.

Main Methods:

• Quantum chemical calculations were employed.
• Analysis included Natural Bond Orbital (NBO) and Energy Decomposition Analysis (EDA).
• Compounds of the general composition Ph₃P-C-L were studied, with L being neutral or anionic.

Main Results:

• Electronic structure, dissociation energies, bond lengths, and Wiberg bond indices are highly dependent on the nature and charge distribution of ligand L.
• NBO analysis indicates a preference for unsymmetrical bonding (P=C-L or P-C=L), with Lewis structures featuring lone pairs on carbon also being valid.
• EDA reveals a preference for dative and ylidic bonds (e.g., P→C⁻-L).
• Anionic systems show a greater preference for ylidic bonding compared to neutral analogues.

Conclusions:

• The bonding in metalated ylides is complex and often requires considering multiple resonance structures.
• Anionic metalated ylides display distinct electronic and bonding characteristics compared to neutral bisylides.