Browsing by Subject "N-heterocyclic carbenes"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    1-Ferrocenylmethyl-3-(2,4,6-tri-methyl-benzyl)-1H-imidazolidin-3-ium iodide and trans-bis-(3-benzyl-1-ferrocenylmethyl-1H-imidazolidin-2-yl-idene) diiodidopalladium(II)
    (2012) Daran J.-C.; Demirhan F.; Yldrm O.; Çetinkaya B.
    Owing to increasing inter-est in the use of N-heterocyclic carbenes (NHCs) based on imidazolidinium ions as ligands in the design of highly efficient transition-metal-based homogeneous catalysts, the characterizations of the 1-ferrocenylmethyl-3-(2,4,6-trimethyl-benzyl)imidazolidin-3-ium iodide salt, [Fe(C 5H 5)(C 19H 24N 2)]I, (I), and the palladium complex trans-bis-(3-benzyl-1-ferrocenylmethyl-1H- imidazolidin-2-yl-idene)diiodidopalladium(II), [Fe 2Pd(C 5H 5) 2(C 16H 17N 2) 2I 2], (II), are re-ported. Compound (I) has two iodide anions and two imidazolidinium cations within the asymmetric unit (Z′ = 2). The two cations have distinctly different con-formations, with the ferrocene groups orientated exo and endo with respect to the N-heterocyclic carbene. Weak C-H donor hydrogen bonds to both the iodide anions and the π system of the mesitylene group combine to form two-dimensional layers perpendicular to the crystallographic c direction. Only one of the formally charged imidazolidinium rings forms a near-linear hydrogen bond with an iodide anion. Complex (II) shows square-planar coordination around the Pd II metal, which is located on an inversion centre (Z′ = 0.5). The ferrocene and benzyl substituents are in a trans-anti arrangement. The Pd-C bond distance between the N-heterocyclic carbene ligands and the metal atom is 2.036 (7) Å. A survey of related structures shows that the lengthening of the N-C bonds and the closure of the N-C-N angle seen here on metal complexation is typical of similar NHCs and their complexes. © 2012 International Union of Crystallography.
  • No Thumbnail Available
    Item
    Dinuclear N-heterocyclic carbene silver complexes: Synthesis, luminescence and catalytic studies
    (Elsevier B.V., 2019) Demir Atlı D.; Gülle S.
    A new dibenzimidazole compound (1) and three dibenzimidazolium salts (2a-2c) were prepared. Reactions of these salts with silver(I) oxide in methanol led to dinuclear N-heterocyclic carbene silver complexes (3a-3c). All of the compounds were characterized by 1H NMR, 13C NMR and elemental analyses. Molecular weights of the silver complexes were confirmed by MALDI-TOF mass spectrometry. Preliminary catalytic studies using all the silver complexes were performed on three-component coupling reaction of p-formaldehyde, piperidine and phenylacetylene. Complexes 3a and 3c exhibited good catalytic activities under neat conditions. The silver complexes showed luminescence properties in CH3CN at room temperature. © 2018 Elsevier B.V.