Mg metal reduction of the divalent precursor PdCl(2)(CNAr(Dipp2))(2) (Dipp = 2,6-diisopropylphenyl) provides the isolable, two-coordinate Pd(0) bis-isocyanide, Pd(CNAr(Dipp2))(2), which is the first stable monomeric isocyanide complex of zerovalent palladium. Variable temperature (1)H NMR and FTIR studies on Pd(CNAr(Dipp2))(2) in the presence of added CNAr(Dipp2) revealed that free and coordinated isocyanide undergo rapid exchange, but the components do not form a stable tris-isocyanide complex. Bis-isocyanide Pd(CNAr(Dipp2))(2) is active for oxidative addition reactions and readily reacts with benzyl chloride and mesityl bromide to form Pd(Cl)(Bz)(CNAr(Dipp2))(2) and Pd(Br)(Mes)(CNAr(Dipp2))(2), respectively. Room-temperature Suzuki-Miyaura cross-coupling reactions are mediated by Pd(CNAr(Dipp2))(2). Coordinatively and electronically unsaturated substrates also react with Pd(CNAr(Dipp2))(2). Addition of thallium(I) triflate (TlOTf) to Pd(CNAr(Dipp2))(2) results in the salt [TlPd(CNAr(Dipp2))(2)]OTf, while addition of O(2) results in the peroxo complex (eta(2)-O)Pd(CNAr(Dipp2))(2). Most remarkably, 2 equiv of nitrosobenzene react with Pd(CNAr(Dipp2))(2) to form the square planar complex (kappa(1)-N-PhNO)(2) Pd(CNAr(Dipp2))(2), the geometry of which strongly suggests the formation of a divalent Pd center. With the aid of density functional theory calculations, this valence change is rationalized in terms of a formal reduction of the bond order in each NO unit to 1.5.
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http://dx.doi.org/10.1021/ja905338x | DOI Listing |
Chem Sci
June 2024
School of Chemistry, University of Nottingham, University Park Nottingham NG7 2RD UK
The scission and homologation of CO is a fundamental process in the Fischer-Tropsch reaction. However, given the heterogeneous nature of the catalyst and forcing reaction conditions, it is difficult to determine the intermediates of this reaction. Here we report detailed mechanistic insight into the scission/homologation of CO by two-coordinate iron terphenyl complexes.
View Article and Find Full Text PDFDalton Trans
June 2024
Department of Chemistry, University of Toronto, 80 St George St, Toronto, ON, M5S3H6, Canada.
Two coordinate boron cations are rare. Herein we report the synthesis of [RNSiMeCH]BF (R = Dipp 3, 1-Ad 5) (Dipp = CH(iPr), Ad = CH) the reaction of BF with the corresponding dilithiated diamides. Subsequent abstraction of fluoride provided the corresponding borinium salts, [(RNSiMeCH)B][B(CF)] (R = Dipp 6, 1-Ad 8).
View Article and Find Full Text PDFChemistry
August 2024
Department of Chemistry and Biochemistry, The University of Texas at Arlington, Box 19065, Arlington, Texas, 76019-0065, United States.
Sterically loaded, anionic pyridine has been synthesized and utilized successfully in the stabilization of a isoleptic series of coinage metal complexes. The treatment of [4-(PhB)-2,6-TripPy]K (Trip=2,4,6-PrCH) with CuBr(PPh), AgCl(PPh) or AuCl(PPh) (Py=pyridine) afforded the corresponding [4-(PhB)-2,6-TripPy]M(PPh) (M=Au, Ag, Cu) complexes, via salt metathesis, as isolable, crystalline solids. Notably, these reactions avoid the facile single electron transfer chemistry reported with the less bulky ligand systems.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
May 2024
Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, Guangdong Basic Research Center of Excellence for Functional Molecular Engineering, School of Chemistry, IGCME, Sun Yat-sen University, Guangzhou, 510275, China.
Lead-based radicals in the oxidation state of +1 are elusive species and are highly challenging to isolate in the condensed phase. In this study, we present the synthesis and characterization of the first isolable free plumbylyne radical 2 bearing a one-coordinate Pb(I) atom. It reacts with an N-heterocyclic carbene (NHC) to afford a two-coordinate NHC-ligated Pb(I) radical 3.
View Article and Find Full Text PDFJ Am Chem Soc
March 2024
Metalorganic and Inorganic Materials, Department of Chemistry, Technische Universität Berlin, 10623 Berlin, Germany.
The formation of isolable monatomic Bi complexes and Bi radical species is challenging due to the pronounced reducing nature of metallic bismuth. Here, we report a convenient strategy to tame Bi and Bi atoms by taking advantage of the redox noninnocent character of a new chelating bis(germylene) ligand. The remarkably stable novel Bi cation complex , supported by the new bis(iminophosphonamido-germylene)xanthene ligand [(P)Ge(Xant)Ge(P)] , [(P)Ge(Xant)Ge(P) = PhP(NBu)Ge(Xant)Ge(NBu)PPh, Xant = 9,9-dimethyl-xanthene-4,5-diyl], was synthesized by a two-electron reduction of the cationic BiI precursor complex with cobaltocene (CpCo) in a molar ratio of 1:2.
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