| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1307904 | Inorganica Chimica Acta | 2016 | 8 Pages |
•Bis-imidazolium dication ligands.•Silver(I) and palladium(II) complex.•X-ray crystal structure of 1,5-bis(4-(imidazol-1-yl)phenol-imidazolium-1-yl)pentane dibromide.•Catalysis.
Two new pentamethylene-functionalized bis-imidazolium dication ligands L1 and L2 (L1 = 1,5-bis(4-(imidazolium-1-yl-phenol)pentane dibromide; L2 = 1,5-bis(1-vinylimidazolium-1-yl)pentane dibromide) bearing IP (4-(imidazol-1-yl)phenol) and VI (1-vinylimidazole)-functionality have been prepared via the reaction of 1,5-dibromopentane with a substituted imidazole derivative. The bis-imidazolium dication ligands L1 and L2 on reaction with Ag2O in DCM:MeOH, followed by anion substitution with AgBF4 led to the formation of silver(I) complexes [Ag2(PC(CH2)5CP)2][BF4]2 (PC(CH2)5CP = 1,5-bis(4-(imidazolium-1-yl-phenol) pentane (1) and [Ag2(VC(CH2)5CV)2][BF4]2 (VC(CH2)5CV = 1,5-bis(1-vinylimidazolium-1-yl)pentane (2). Transmetalation of the bis-NHC ligand from [Ag2(PC(CH2)5CP)2][BF4]2 and [Ag2(VC(CH2)5CV)2][BF4]2 by palladium(II) salt [PdCl2(CH3CN)2] in DMSO gave [PdCl(PC(CH2)5CP)(CH3CN)]BF4 (3) and [PdCl(VC(CH2)5CV)(CH3CN)]BF4 (4), respectively. The new ligands as well as their silver(I) and palladium(II) complexes have been characterized by elemental analysis, electronic, IR, 1H and 13C NMR, and FAB-MS spectroscopy. The molecular structure of the representative ligand L1 has been determined by single crystal X-ray analysis. The palladiumII NHC complexes 3 and 4 exhibited good activity in a model Heck and Suzuki–Miyaura coupling reaction.
Graphical abstractThe syntheses and characterization of two new pentamethylene-functionalized bis-imidazolium dication ligands L1 and L2 (L1 = 1,5-bis(4-(imidazolium-1-yl-phenol)pentane dibromide; L2 = 1,5-bis(1-vinylimidazolium-1-yl)pentane dibromide) as well as their silver(I) and palladium(II) complexes are reported. The palladiumII NHC complexes 3 and 4 were shown to exhibit efficient catalytic activity in Heck and Suzuki–Miyaura coupling reaction.Figure optionsDownload full-size imageDownload as PowerPoint slide
