Metal-ligand bonding situation in ruthenophanes containing ij-xylylene-linked bis(NHC)cyclophane ligands

Autor(es)

Ortolan, Alexandre O. ; Caramori, Giovanni F. ; Garcia, Leone C. ; Parreira, Renato L. T. ; Bento, Mariana V. B.

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF ORGANOMETALLIC CHEMISTRY; v. 830, p. 100-108, FEB 15 2017.
• Citações Web of Science: 2

Resumo

The electronic structure of a isomeric series of ruthenophanes containing NHC-cyclophanes derived from imidazolium-linked cyclophanes was studied in the light of energy decomposition analysis and natural bond orbitals. The relative stability, bridge tensions and the metal-ligand bonding situation in a set complexes (1-9) formed by isomers of the ij-xylylene-linked bis(NHC)cyclophane ligand were determined. Isomers containing aromatic moieties in both anti and syn conformations were evaluated. The relative stability of the isomeric series was evaluate by means of electronic structure calculations at DFT level, including the already synthesized and characterized Baker's complex 1, which was identified as the most stable, followed by complex 4. Our calculations reveal that by using as starting material a imidazolium-linked-m,o-cyclophane salt under similar conditions as used by Baker {[}1], the complex 4 can be likewise obtained. The calculated strain energies imposed on the ligand tether revealed that the strain in NHC-cyclophanes bridges is considerably high. The EDA-NOCV results concerning metal-ligand bonding situation reveal that the stabilization between the cyclophanes and the [RuCl](+) fragments is mainly due to the orbital term, followed by the electrostatic interaction. The orbital stabilization is comprised mainly of sigma-donation from carbenes to ruthenium(II) ion, which is the most significant contribution, followed by the metal -> ligand pi-backdonation. (C) 2016 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 11/07623-8 - Utilização de métodos mecânicos-quânticos para estudo das ligações e interações químicas em sistemas auto-organizados com aplicação em catálise, química medicinal, eletrocromismo, armazenamento e conversão de energia
• Beneficiário: Renato Luis Tame Parreira
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores