Thais R. Cruz, Juliana I. P. Maia, Pedro I. S. Maia, Antonio E. H. Machado, Beatriz E. Goi, Lionel Delaude, Valdemiro P. Carvalho-Jr
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引用次数: 0
Abstract
Heterobimetallic complexes offer greater versatility for applications in homogeneous catalysis than their monometallic counterparts. To take advantage of this synergy, three [Pd(N,N,S-TSC)(4-NH2Py)] complexes (mono-PdMe, mono-PdMe,Me and mono-PdPh) were synthesized from [PdCl2(MeCN)2] and appropriate thiosemicarbazide (TSC) ligand precursors, followed by the addition of 4-aminopyridine (4-NH2Py). The reaction of these mono-PdL complexes with [RuCl2(η6-p-cymene)]2 then afforded three heterobimetallic complexes with the generic formula [{RuCl2(p-cymene)}-μ-{(4-NH2Py)Pd (TSC)}] (Ru-PdMe, Ru-PdMe,Me and Ru-PdPh). All these novel compounds were characterized by elemental analysis, spectroscopic techniques, cyclic voltammetry, and density functional theory (DFT) calculations. The molecular structure of mono-PdMe was determined by X-ray diffraction analysis. The Ru-PdL complexes were evaluated as bifunctional catalysts in the reductive Heck coupling of norbornadiene (NBD) with iodobenzene and the ring-opening metathesis polymerization (ROMP) of phenylnorbornene (Ph-NBE). They were very active for the reductive Heck reaction, reaching yields higher than 90% when a [Pd]/[NBD]/[PhI] ratio of 1/418/1344 was employed at 120°C. Upon activation with ethyl diazoacetate (EDA), they were also able to polymerize Ph-NBE with yields around 70% using a [Ph-NBE]/[Ru-PdL] ratio of 3000 at 50°C for 30 min. The Ru-PdMe,Me complex showed the highest activity in the ROMP of Ph-NBE and was successfully applied for mediating the synthesis of poly (Ph-NBE) from NBD via tandem catalysis.
期刊介绍:
All new compounds should be satisfactorily identified and proof of their structure given according to generally accepted standards. Structural reports, such as papers exclusively dealing with synthesis and characterization, analytical techniques, or X-ray diffraction studies of metal-organic or organometallic compounds will not be considered. The editors reserve the right to refuse without peer review any manuscript that does not comply with the aims and scope of the journal. Applied Organometallic Chemistry publishes Full Papers, Reviews, Mini Reviews and Communications of scientific research in all areas of organometallic and metal-organic chemistry involving main group metals, transition metals, lanthanides and actinides. All contributions should contain an explicit application of novel compounds, for instance in materials science, nano science, catalysis, chemical vapour deposition, metal-mediated organic synthesis, polymers, bio-organometallics, metallo-therapy, metallo-diagnostics and medicine. Reviews of books covering aspects of the fields of focus are also published.