Search results for "PALLADIUM"
showing 10 items of 956 documents
Synthesis and Reactivity toward Isonitriles of (2-Aminoaryl)palladium(II) Complexes
2001
Mixtures of “Pd(dba)2” (dba = dibenzylideneacetone) and 2,2‘-bipyridine (bpy; 1:2) or N,N,N‘,N‘-tetramethylethylenediamine (tmeda; 1:1) react with 2-bromo-4-nitroaniline to give [Pd{C6H3NH2-2-NO2-5}Br(N−N)] (N−N = bpy (1b), tmeda (1b‘)). Reactions of 2-iodoaniline with mixtures of “Pd(dba)2” and isonitriles RNC (R = C6H3Me2-2,6 (Xy), 2:1:2 molar ratios; R = tBu, 2.9:1:2 molar ratios) result in the formation of the complexes [Pd{κ2C,N-C(NXy)C6H4NH2-2}I(CNXy)] (2a) and trans-[Pd{C(NtBu)C6H4NH2-2}I(CNtBu)2] (3a*). The reactions of [Pd{C6H4NH2-2}I(bpy)] and 1b‘ with RNC give the complexes trans-[Pd{C(NR)C6H3NH2-2-Y-5}}X(CNR)2] (Y = H, X = I, R = Xy (3a), tBu (3a*); Y = NO2, X = Br, R = Xy (3b),…
Coordination properties of imino(2-pyridyl)methylpalladium(II) compounds. Preparation and thermal rearrangement of binuclear adducts with palladium(I…
1988
Abstract The imino(2-pyridyl)methylpalladium(II) compound py-2-C(R′)NR (R = C 6 H 4 OMe-p, R′ = trans-PdCl(PPh 3 ) 2 ) reacts with [PdCl 2 (CH 2 CHPh)] 2 , [PdCl 2 - (NCMe) 2 ], and K[PtCl 3 (CH 2 CH 2 )] to give binuclear complexes [MCl 2 {py-2- C(R′)NR}] (M = Pd, Pt), in which the α-diimino group acts as a chelating bidentate ligand. In hot 1,2-dichloroethane, these complexes undergo a PPh 3 and chloride ligand exchange at rates which depend markedly on the metal M (Pd ⪢ Pt), to yield the new derivatives [MCl(PPh 3 ){py-2-C(cis-PdCl 2 (PPh 3 ))NR}]. The ligand exchange is followed by a much slower decomposition to [MCl 2 (PPh 3 ) 2 ]. Labile intermediates of the same type, [MCl(PPh …
Five-coordinate complexes of palladium(ii) and platinum(ii) with α-diimine and 1,5-cyclooctadiene ligands
2001
The five-coordinate complexes [PtMe(cod)(N–N′)]BF4 [cod = η2,η2-cyclooctadiene, N–N′ = (6-R2)C5H3N-2-CHNR1 (R1 = C6H4OMe-4, R2 = H (1), Me (2); R1 = CMe3, R2 = H (3), Me (4); R1 = (R)-bornyl, R2 = Me (5))] are readily obtained from the reaction of [PtClMe(cod)] with N–N′ in the presence of NaBF4. The preparation of [PtMe(cod)(6)]BF4 (6 = 4-MeOC6H4NCHCHNC6H4OMe-4), [PdMe(cod)(N–N′)]BF4 and [PtCl(cod)(N–N′)]BF4 (N–N′ = 2, 4) requires chloride abstraction by AgBF4 from [PtClMe(cod)], [PdClMe(cod)] and [PtCl2(cod)], respectively, followed by coordination of N–N′. The NMR spectral data suggest a trigonal-bipyramidal structure with chelating cod and N–N′ ligands, where the α-diimine and one CC bo…
Modular functionalized polyphosphines for supported materials: previously unobserved (31)P-NMR «through-space» ABCD spin systems and heterogeneous pa…
2014
The modular design of polyphosphines, diversely functionalized for facile immobilization on virtually any kind of support, is reported. Previously unobserved ABCD (31)P NMR spin-spin systems evidence the control exercised on the polyphosphines conformation. We illustrate the catalytic performance at low Pd loading of the recyclable immobilized polyphosphines in C-C bond formation reactions.
Synthesis and characterization of new allyl palladium complexes with thionate ligands; X-ray molecular structures of [Pd3(η3-C4H7)3{pm(Me)2S}2](CF3SO…
1999
Abstract The reaction of [Pd(η3-C4H7)]CF3SO3 (η3-C4H7=η3-2-MeC3H4) (1), prepared in situ by reaction of [Pd(η3-C4H7)Cl]2 with AgCF3SO3, with various thionate ligands, gives new polymeric complexes formulated as [Pd(η3-C4H7)(RS)]n (2) [RS=pyS (pyridine-2-thionate)], im(Me)S(imidazole-3-methyl-2-thionate) (3), pm(Me)2S (pyrimidine-4,6-dimethyl-2-thionate) (4). A solution of 4 contaminated with KCF3SO3 evolves to give crystals that correspond to a new polymeric species whose X-ray crystal molecular structure indicates the presence of cationic infinite chains built of trinuclear units, [Pd3(η3-C4H7)3{pm(Me)2S}2]+ (5). Finally, the formation of a mononuclear thionate-containing palladium complex…
Dinuclear Ortho-Metalated Palladium(II) Compounds with N,N- and N,O-Donor Bridging Ligands. Synthesis of New Palladium(III) Complexes
2011
New dinuclear ortho-metalated palladium(II) compounds with N,N′-diarylformamidinates, Pd2[(C6H4)PPh2]2[R′NC(H)NR′]2 (R′ = C6H5, 3a; R′ = p-CH3C6H4, 3b; R′ = p-CH3OC6H4, 3c) and N,O-donor ligands, Pd2[(C6H4)PPh2]2[N,O]2 (N,O = succinimidate (5), phtalimidate (6), 2-hydroxypyridinate (7), acetanilidate (8)) have been synthesized and characterized by NMR spectroscopy and X-ray diffraction methods. The oxidation with iodobenzene dichloride gave new and rare Pd26+ compounds, Pd2[(C6H4)PPh2]2[R′NC(H)NR′]2Cl2 (R′ = C6H5, 4a; R′ = p-CH3C6H4, 4b). DFT calculations on the Pd24+ → Pd26+ oxidation reaction show that the substituents on the amidinate N atoms have a greater effect on the reaction energy …
Palladium-Catalyzed Skeletal Rearrangement of Spirotricyclic Olefins: A Facile One-Pot Strategy for the Synthesis of a Novel Motif with Cyclopentene …
2013
The first utilization of acyclic cyclopropane bearing spirocyclic olefines for the generation of stereospecific complex fused ring systems with an achiral catalyst is reported.
Synthesis, properties, antitumor and antibacterial activity of new Pt(II) and Pd(II) complexes with 2,2′-dithiobis(benzothiazole) ligand
2017
Mono- and binuclear Pt(II) and Pd(II) complexes with 2,20-dithiobis(benzothiazole) (DTBTA) ligand are reported. [Pt(DTBTA)(DMSO)Cl]Cl∙CHCl3 (1) and [Pd2(m-Cl)2(DTBTA)2]Cl2 (2) have been synthesized and structurally characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy, MS spectrometry and the content of platinum and palladium was determined using a flame atomic spectrometer. Two different coordination modes of 1 and 2 complexes were found; in both complexes, the coordination of Pt(II) and Pd(II) ions involves the N(3) atoms of the ligand but the binuclear complex 2, is a cis-chloro-bridged palladium complex. Evaluation of their in vitro antitumor activity against two human tu…
Synthesis and characterization of cyclometallated palladium(II) complexes with 2-(diphenylphosphino)benzaldehyde
2013
New palladium(II) complexes containing 2-(diphenylphosphino)benzaldehyde a (Ph2P(o-C6H4CHO), displaying different coordination modes, have been synthesized in moderate to good yields (62–91%). The cyclometallated palladium(II) complexes [Pd(C^N)(Ph2 P(o-C6H4CHO)(Cl)] (1–4) in which a is P-monodentate have been prepared by reacting it with selected cyclometallated precursors containing bridging chlorides [Pd(C^N)(μ-Cl)]2 [C^N=2-phenylpyridine (Phpy), 7,8-benzoquinoline (Bzq), azobenzene (Phazo), and 2-phenyloxazoline (Phox), respectively]. A rigid P,O-chelating behavior of a, confirmed by the crystal structure determination of [Pd(Phox)(Ph2 P (o-C6H4CHO)][CF3SO3] (8), is observed in complexe…
"Through-space" 31P spin-spin couplings in ferrocenyl tetraphosphine coordination complexes: improvement in the determination of the distance depende…
2008
Abstract From the analysis of several nickel and palladium halide complexes of a constrained ferrocenyl tetraphosphine, the existence in solution phase of unique 31P–31P “through-space” nuclear spin–spin coupling constants (JPP) had been previously evidenced. Due to the blocked conformation of the species in solution, and based on the NMR spectra obtained for the complexes and their corresponding solid state X-ray structures, these JPP constants had been shown to clearly depend on the mutual spatial position of the corresponding phosphorus atoms. Herein, the quantitative correlation disclosed at that time (P⋯P distance dependence of coupling constants) is remarkably confirmed, and mathemati…