Noncovalent interactions in a transition-metal triphenylphosphine complex: a density functional case study

Area of Science:

• Computational Chemistry
• Organometallic Chemistry
• Quantum Chemistry

Background:

• Accurate calculation of metal-ligand binding enthalpies is crucial in organometallic chemistry.
• Noncovalent interactions significantly contribute to the overall metal-ligand interaction energy.
• Previous studies have shown varying success with different density functional theory (DFT) methods.

Purpose of the Study:

• To investigate the performance of various density functionals in predicting the binding enthalpy of a triphenylphosphine ligand in a specific ruthenium complex.
• To assess the importance of including dispersion corrections and using highly parametrized functionals for accurate binding energy calculations.
• To identify the most reliable DFT methods for this type of organometallic system.

Main Methods:

• Employing standard (BP86, B3LYP), dispersion-corrected (B3LYP-D, B97-D), and highly parametrized (M05, M06 series) density functionals.
• Calculating the binding enthalpy of the triphenylphosphine ligand in the ruthenium complex Ru(CO)Cl(PPh(3))(3)(CHCHPh).
• Comparing computational results with experimental data from Sponsler et al. (Inorg. Chem. 2007).

Main Results:

• The study found that standard DFT functionals provided less accurate binding enthalpy values.
• Dispersion-corrected functionals (B97-D) and the M06 series of functionals showed superior agreement with experimental data.
• Noncovalent interactions were identified as a major component of the metal-ligand binding energy, necessitating their proper treatment.

Conclusions:

• The B97-D and M06-family density functionals are recommended for accurately calculating the binding enthalpy of triphenylphosphine ligands in similar ruthenium complexes.
• Properly accounting for noncovalent interactions is essential for reliable computational studies in organometallic chemistry.
• This work provides valuable insights for selecting appropriate computational methods in catalysis and materials science.