Search results for "Transmetalation"
showing 6 items of 26 documents
Coordination versatility of pyridine-functionalized N-heterocyclic carbenes: a detailed study of the different activation procedures. Characterizatio…
2005
Three different reaction procedures for the coordination of N-n-butyl-N'-(2-pyridylmethyl)imidazolium salt have produced new N-heterocyclic complexes of Rh and Ir. The direct reaction of the imidazolium salt with [IrCl(cod)](2) provides a NHC-Ir(III)-H complex, while transmetalation from a silver-NHC complex and deprotonation with NEt(3) give new NHC complexes of M(I) and M(III) when reacting with [MCl(cod)](2) or [MCl(coe)(2)](2) (M = Rh, Ir). The crystal structures of the biscarbene Rh(III) and Ir(III) complexes are described. The catalytic properties of the compounds obtained have been tested in the hydrosilylation of acetylenes, the cyclization of acetylenic carboxylic acids, and hydrog…
Electrical Behaviour of Heterobimetallic [MM′(EtCS2)4] (MM′=NiPd, NiPt, PdPt) and MM′X-Chain Polymers [PtM(EtCS2)4I] (M=Ni, Pd)
2012
Herein, we report the isolation of new heterobimetallic complexes [Ni0.6Pd1.4ACHTUNGTRENUNG(EtCS2)4] (1), [NiPtACHTUNGTRENUNG(EtCS2)4] (2) and [Pd0.4Pt1.6ACHTUNGTRENUNG(EtCS2)4] (3), which were constructed by using transmetallation procedures. Subsequent oxidation with iodine furnished the MM'X monodimensional chains [Ni0.6Pt1.4ACHTUNGTRENUNG(EtCS2)4I] (4) and [Ni0.1Pd0.3Pt1.6ACHTUNGTRENUNG(EtCS2)4I] (5). The physical properties of these systems were investigated and the chain structures 4 and 5 were found to be reminiscent of the parent [Pt2ACHTUNGTRENUNG(EtCS2)4I] species. However, they were more sensitively dependent on the localised nature of the charge on the Ni ion, which caused spont…
Benzodiselenagermoles and spirobisbenzodiselenagermoles
1993
Synthesis of benzodiselenagermoles and bisbenzodiselenagermoles was carried out by transmetallation group 4 group 14 between diselenophenylenezirconocenes and dialkyl-, diaryl- or alkylaryldichlorogermanes, aryltrichlorogermane or germanium tetrachloride. The new compounds were studied by 1H, 77Se NMR and mass spectrometry. In the case of compounds with substituted phenyl groups, double irradiation and 2D NMR experiments were performed to determine the chemical shifts of the two selenium atoms. The crystal structure of a spirobisbenzodiselenagermole has been established by X-ray diffraction analysis.
Nickel as a Lewis Base in a T‐Shaped Nickel(0) Germylene Complex Incorporating a Flexible Bis(NHC) Ligand
2018
Flexible, chelating bis(NHC) ligand 2, able to accommodate both cis- and trans-coordination modes, was used to synthesize (2)Ni(η 2 -cod), 3. In reaction with GeCl2, this produced (2)NiGeCl2, 4, featuring a T-shaped Ni(0) and a pyramidal Ge center. Complex 4 could also be prepared from [(2)GeCl]Cl, 5, and Ni(cod)2, in a reaction that formally involved Ni-Ge transmetalation, followed by coordination of the extruded GeCl2 moiety to Ni. A computational analysis showed that 4 possesses considerable multiconfigurational character and the Ni→Ge bond is formed through σ-donation from the Ni 4s, 4p, and 3d orbitals to Ge. (NHC)2Ni(cod) complexes 9 and 10, as well as (NHC)2GeCl2 derivative 11, incor…
Hexagonal Microparticles from Hierarchical Self-Organization of Chiral Trigonal Pd3L6 Macrotetracycles
2021
Construction of structurally complex architectures using inherently chiral, asymmetric, or multi-heterotopic ligands is a major challenge in metallosupramolecular chemistry. Moreover, the hierarchical self-organization of such complexes is unique. Here, we introduce a water-soluble, facially amphiphilic, amphoteric, chiral, asymmetric, and hetero-tritopic ligand derived from natural bile acid, ursodeoxycholic acid. We show that via the supramolecular transmetalation reaction, using nitrates of Cu(II) or Fe(III), and subsequently Pd(II), a superchiral Pd3L6 complex can be obtained. Even though several possible constitutional isomers of Pd3L6 could be formed, because of the ligand asymmetry a…
Investigation of the aqueous transmetalation of pi-allylpalladium with indium: some theoretical and experimental evidence about the nature of allylin…
2005
In this paper we report some theoretical and experimental evidence concerning the nature of the allyl-In intermediate generated by umpolung of allyl-Pd complexes in the Pd(OAc)(2)/TPPTS catalysed allylation reaction of benzaldehyde. The allylic substrate reacts at the substituted terminus, because of the formation of an equilibrating mixture of eta(1)-allyl-In(I) specie with the gamma-substituted regioisomer being more reactive.