The structure of dichlorotris(triphenylphosphine)ruthenium(II): a DFT study of interaction energies and substitution mechanism

• Published in: Molecular simulation Vol. 47; no. 8; pp. 628 - 635
• Main Authors: de Sousa, José Antônio, de Oliveira, Mayrla Letícia Alves, Lima, Francisco das Chagas Alves, Silva Sá, José Luiz, Lima Neto, Benedito dos Santos, Costa, Luciano Tavares, Carneiro, José Walkimar de Mesquita
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 24.05.2021; Taylor & Francis Ltd
• Subjects: agostic interaction; Bonding strength; coordination energy; Density functional theory; energy decomposition; Piperidine; Ruthenium; Ruthenium compounds; Ruthenium(II) complex; Substitutes; substitution mechanism
• ISSN: 0892-7022; 1029-0435
• DOI: 10.1080/08927022.2021.1895434

The structure and substitution energies of dichlorotris(triphenylphosphine)ruthenium(II) complex, [RuCl 2 (PPh 3 ) 3 ], was computed with ten different methods at the density functional theory level using a composition of basis sets. The PBE0 functional led to the best description of bond lengths, while the MN12-L functional yielded the best results for bond angles. For calculation of the Ru-P bond dissociation energies, the best results were obtained with the M06-L functional. The nature of the Ru-P bond was discussed in terms of donation and back-donation as well as in terms of the steric versus covalent contributions to the bonding. In the square pyramidal structure, the apical Ru-P bond is considerably tighter than the basal Ru-P bonds. This is due to an interaction of the apical PPh 3 ligand with a high d character orbital on the Ru atom, favouring back-donation, leading to a short Ru-P distance and strong bonding energy. Additionally, we also investigated the equilibrium structures and mechanism for the substitution of one of the PPh 3 group by the piperidine molecule. The equilibrium between the several species involved in the substitution process indicates that addition of the piperidine molecule to [RuCl 2 (PPh 3 ) 3 ] followed by elimination of a PPh 3 unity is the pathway with lower energy.