Cyanide complexes of Ti(IV): a computational study.

Area of Science:

• Computational chemistry
• Inorganic chemistry
• Quantum chemistry

Background:

• Cyanide and isocyanide ligands exhibit distinct bonding properties.
• Titanium(IV) complexes with varying ligand numbers are of interest for their electronic structures.

Purpose of the Study:

• To investigate the structural preferences and bonding in titanium(IV) cyanide/isocyanide complexes.
• To determine the influence of ligand number and solvent on complex stability.
• To elucidate the electronic factors governing cyanide versus isocyanide isomer preference.

Main Methods:

• Density functional theory (B3LYP) calculations.
• Coupled-cluster techniques [CCSD(T)] including solvent effects.
• Analysis of sigma-bonding capabilities and electronic structures.

Main Results:

• The isocyanide isomer is generally more stable for titanium(IV) complexes [Ti(CN)(n)](4-n) (n=1-5).
• The cyanide isomer is preferred for the hexacyanocomplex (n=6) due to enhanced sigma-bonding.
• Solvent effects consistently favor the formation of the hexacyanocomplex, regardless of the solvent.

Conclusions:

• Ligand number significantly influences the cyanide/isocyanide isomer preference in titanium(IV) complexes.
• Sigma-bonding strength becomes a dominant factor for larger ligand numbers, favoring cyanide.
• Computational methods provide insights into the stability and bonding of inorganic complexes.