920282-22-0Relevant articles and documents
Bis(functionalized NHC) palladium(II) complexes via a postmodification approach
Teng, Qiaoqiao,Upmann, Daniel,Ng Wijaya, Sheena Ai Zi,Huynh, Han Vinh
, p. 3373 - 3384 (2014)
A series of 20 bis(functionalized NHC) Pd(II) complexes have been conveniently synthesized through postmodification reactions of the common parent NHC complexes trans-[PdBr2(C3Br-bimy)2] (1a) and trans-[PdBr2(C3Br-imy)2] (1b) (C 3Br-bimy = 1-benzyl-3-(3-bromopropyl)benzimidazolin-2-ylidene and C3Br-imy = 1-benzyl-3-(3-bromopropyl)imidazolin-2-ylidene) with an N-C3Br tether. Depending on the nature of the nucleophiles added, competing bromido ligand displacements also occurred. In comparison to the conventional access to functionalized NHC complexes, which involves metalation of individually prefunctionalized azolium salts, this highly modular method proves more effective in cost and time savings. The tetraalkylammonium- functionalized complex trans-[PdBr2(C3NEt 3-bimy)2]Br2 (14) as a product of the second-generation postmodification of complex 1a was also tested for its catalytic activity in Mizoroki-Heck coupling reactions to study and model the effect of a catalytic amount of ammonium salt additive in Pd-catalyzed C-C coupling reactions. The ammonium functionalities in this complex exhibit a positive effect on the catalysis in comparison to its parent complexes.
Synthesis, spectroscopic characterization and density functional studies of a bis-benzimidazole derivative and of its complexes with palladium(II) halides
Aghatabay, Naz Mohammed,Altun, Ahmet,Gürbüz, Mustafa Ulvi,Türkyilmaz, Murat
, p. 905 - 912 (2014/08/18)
The 2,6-bis(benzimidazol-2′-ylthiomethyl)pyridine (L) ligand and its palladium(II) complexes [Pd(L)X]X (X = Cl, Br, and I) have been synthesized and characterized by spectroscopic data acquisition. The ligand (L) was prepared by conventional heating as well as by microwave irradiation. Microwave irradiation shows additional features, including an easy workup, a much faster reaction and higher yields. The molar conductivity data reveal that the complexes form a 1:1 electrolyte in DMSO. The geometries, ground-state energetics and vibrational spectra of (L) and of its complexes have been elucidated, in terms of quantum chemical calculations. In the mononuclear complexes, the palladium atom is coordinated to three nitrogen atoms and one terminal halogen atom in a slightly distorted square planar arrangement. The present elemental analyses, FT-IR (mid, far), 1H and 13C NMR spectra are in good accordance with the square planar geometry around the Pd ion. The thermal behaviors of the complexes have been assessed by thermal gravimetric and differential thermal analyses.
Unexpected isomerism in "[Pd(2,9-dimethylphenanthroline)X 2]" (X = Cl, Br, I) complexes: A neutral and an ionic form exist
Rimoldi, Martino,Ragaini, Fabio,Gallo, Emma,Ferretti, Francesco,Macchi, Piero,Casati, Nicola
, p. 3648 - 3658 (2012/05/20)
Complexes of composition "[Pd(2,9-dimethylphenanthroline)X 2]" (X = Cl, Br, I) have long been known and they are used as precursors for the synthesis of other derivatives or as catalysts. In the previous literature, they have invariably been described as neutral square planar complexes, but we have found that a second ionic isomer also exists, having composition [Pd(Neoc)2X]2[Pd2X 6], and that the formation of this isomer occurs under a wider range of conditions than that of the neutral one. Retrospectively, the ionic isomer had surely been obtained in most previous reports even if formation of the neutral one was claimed. The Royal Society of Chemistry 2012.
