Jump to main content
Jump to site search

Issue 39, 2014
Previous Article Next Article

Ruthenium(II) complexes of N-heterocyclic carbenes derived from imidazolium-linked cyclophanes

Author affiliations

Abstract

The present work seeks to characterize, in the light of electronic structure calculations, an unusual metal–[(η1-NHC)2:(η6-arene)] bonding situation in a set of ruthenium(II) complexes containing the ortho-xylylene-linked-bis(NHC)cyclophane ligand (NHC-cyclophane) (1), which binds to the ruthenium center through two carbene carbons and one of the arene rings. The nature of ruthenium(II)–[(η1-NHC)2:(η6-arene)] bonding was investigated in the light of EDA-NOCV, NBO and QTAIM analyses by adopting 1 as a model compound. The interplay between the ortho-cyclophane scaffold with different families of five-membered carbenes, such as imidazole, 1, triazole-based NHCs (Enders’ carbenes), 2, and P-heterocyclic carbenes (PHCs), 3, was investigated. The metal–[(η1-NHC)2:(η6-arene)] bonding situation was also extended to heavier analogues, such as N-heterocyclic silylenes (NHSi) and N-heterocyclic germylenes (NHGe), in order to address how the basicity of NHC, NHSi and NHGe is affected by the cyclophane framework. The results reveal that ruthenium(II)–[(η1-NHC)2:(η6-arene)] is more covalently than electrostatically bonded and that the degree of covalence is larger in PHCs than in NHCs or Enders’ carbenes. It is also revealed that the covalent character in the ruthenium(II)–[(η1-NHGe)2:(η6-arene)] and ruthenium(II)–[(η1-NHSi)2:(η6-arene)] bonds is larger than in ruthenium(II)–[(η1-NHC)2:(η6-arene)].

Graphical abstract: Ruthenium(ii) complexes of N-heterocyclic carbenes derived from imidazolium-linked cyclophanes

Back to tab navigation

Supplementary files

Publication details

The article was received on 19 May 2014, accepted on 24 Jul 2014 and first published on 21 Aug 2014


Article type: Paper
DOI: 10.1039/C4DT01473A
Author version
available:
Download author version (PDF)
Citation: Dalton Trans., 2014,43, 14710-14719

  •   Request permissions

    Ruthenium(II) complexes of N-heterocyclic carbenes derived from imidazolium-linked cyclophanes

    G. F. Caramori, L. C. Garcia, D. M. Andrada and G. Frenking, Dalton Trans., 2014, 43, 14710
    DOI: 10.1039/C4DT01473A

Search articles by author

Spotlight

Advertisements