scholarly journals The Codimerization of Butadiene and Ethylene Catalyzed by Cobaltous Chloride-Ditertiary Phosphine Complexes-Grignard Reagent-ROH. Effects of Ditertiary Phosphine Ligands and Alcohols

1972 ◽  
Vol 45 (8) ◽  
pp. 2586-2590 ◽  
Author(s):  
Teruhiko Kagawa ◽  
Harukichi Hashimoto
Keyword(s):  
Grignard Reagent ◽  
Phosphine Ligands ◽  
Cobaltous Chloride ◽  
Phosphine Complexes

Metal Organic Complexes for Optical Power Limiting

1994 ◽  
Vol 374 ◽  
Author(s):  
Chris M. Lawson ◽  
Tianyi Zhai ◽  
David C. Gale ◽  
Gary M. Gray
Keyword(s):  
Optical Power ◽  
Four Wave Mixing ◽  
Phosphine Ligands ◽  
Coordination Geometry ◽  
Wave Mixing ◽  
Phosphine Complexes ◽  
Organic Complexes ◽  
Metal Organic ◽  
Optical Power Limiting ◽  
532 Nm

AbstractNonlinear optical properties of transition metal-phosphine complexes have been measured at 532 nm by degenerate four-wave mixing. Large second-order molecular hyperpolarizabilities, γ, have been found for complexes containing two phosphine ligands. The measured γ values are closely related to the type and coordination geometry of the phosphine ligands, and the γ values vary as the fifth power of the number of substituents with π-electrons structure.

scholarly journals (DMP)DAB–Pd–MAH: A Versatile Pd(0) Source for Precatalyst Formation, Reaction Screening, and Preparative-Scale Synthesis

2021 ◽  
Author(s):  
Jingjun Huang ◽  
Matthew Isaac ◽  
Ryan Watt ◽  
Joseph Becica ◽  
Emma Dennis ◽  
...  
Keyword(s):  
Room Temperature ◽  
Cone Angle ◽  
Phosphine Ligands ◽  
Coupling Reactions ◽  
Preparative Scale ◽  
Formation Reaction ◽  
Phosphine Complexes ◽  
High Throughput Experimentation ◽  
Large Cone Angle

We report an easily prepared and bench-stable mononuclear Pd(0) source stabilized by a chelating <i>N</i>,<i>N</i>’-diaryldiazabutadiene ligand and maleic anhydride: <sup>DMP</sup>DAB–Pd–MAH. Phosphine ligands of all types, including bidentate phosphines and large cone angle biarylphosphines, rapidly and completely displace the diazabutadiene ligand at room temperature to give air-stable Pd(0) phosphine complexes. <sup>DMP</sup>DAB–Pd–MAH itself is readily soluble and stable in several organic solvents, making it an ideal Pd source for <i>in situ</i> catalyst preparation during reaction screening, as well as solution-dispensing to plate-based reaction arrays for high-throughput experimentation. Evaluation of <sup>DMP</sup>DAB–Pd–MAH alongside other common Pd(0) and Pd(II) sources in microscale reaction screens reveals that <sup>DMP</sup>DAB–Pd–MAH is superior at identifying hits across six different C–N, C–C, and C–O coupling reactions. <sup>DMP</sup>DAB–Pd–MAH, and the phosphine precatalysts derived therefrom, are also effective in preparative-scale cross couplings at low Pd loadings.

Neuartige basische Liganden für die homogenkatalytische Methanolcarbonylierung, XXXI Kationische Bis(Ether-Phosphan)metall-Komplexe der Nickeltriade mit fluktuierendem Verhalten / Novel Basic Ligands for the Homogeneous Catalytic Methanol Carbonylation, XXXI Cationic Bis(Ether-Phosphine)Metal Complexes of the Nickel Triad with Fluxional Behavior

1991 ◽  
Vol 46 (4) ◽  
pp. 432-439 ◽  
Author(s):  
Ekkehard Lindner ◽  
Johannes Dettinger
Keyword(s):  
Metal Complexes ◽  
Nmr Spectra ◽  
Palladium Complexes ◽  
Phosphine Ligands ◽  
Temperature Dependent ◽  
H Nmr ◽  
Phosphine Complexes ◽  
Metal Phosphides ◽  
Ether Oxygen ◽  
Insight Into

The (ether-phosphine) ligands R2PCH2C5H9O (1a-c) [R = Ph (a), Cy (= cyclo-C6H11) (b), n-C3H7 (c); C5H9O = tetrahydropyranyl] are obtained from the corresponding alkali metal phosphides MPR2 (M = Li, Na) and 2-chloromethyltetrahydropyran in ether. Reaction of 1 a-c with either Cl2M(COD) (COD = 1,5-cyclooctadiene) or [Ni(OH2)6]Cl2 in a2:1 ratio leads to the bis(ether-phosphine)metal complexes Cl2M(R2P∾O)2 trans-2b,c, trans-3b, cis-2a,b, cis-3a, and 4a [M = Pd (2), Pt (3), Ni (4)], in which the ligands 1a-c are η1-P-coordinated. In 2—4 Cl- is abstracted by AgClO4 to give the cationic trans-bis(ether-phosphine) complexes [ClM(R2P ∾ O)(R2P~O)][ClO4] (5a, 6a-c, 7a) [M = Ni (5), Pd (6), Pt (7); P∾O = η1-P-coordinated; P~O = η2-O,P-coordinated]. In contrast to 7a, the nickel and palladium complexes 5a and 6a-c show fluxional behavior as demonstrated by temperature dependent 31P{1H} NMR spectra. The coalescence temperatures and estimated free energie enthalpies ΔG≉ of 5a and 6a-c are compared with the corresponding data of the complexes [ClPd(Ph2P ∾ O)(Ph2~O)][ClO4] (8a-10a) [O,P ligand = Ph2PCH2C4H7O (8a), Ph2PCH2C4H7O2 (9a), Ph2PCH2CH2OCH3 (10a)] and give an insight into the relative basicity of the ether oxygen atoms.

scholarly journals The Catalytic Activity of Carbon-Supported Cu(I)-Phosphine Complexes for the Microwave-Assisted Synthesis of 1,2,3-Triazoles

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 185
Author(s):  
Ivy L. Librando ◽  
Abdallah G. Mahmoud ◽  
Sónia A. C. Carabineiro ◽  
M. Fátima C. Guedes da Silva ◽  
Carlos F. G. C. Geraldes ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Cycloaddition Reaction ◽  
Benzyl Bromide ◽  
Phosphine Ligands ◽  
Catalyst Loading ◽  
Microwave Assisted Synthesis ◽  
One Pot ◽  
Microwave Assisted ◽  
Phosphine Complexes ◽  
Multi Walled Carbon Nanotubes

A set of Cu(I) complexes with 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo-[3.3.1]nonane (DAPTA) phosphine ligands viz. [CuX(κP-DAPTA)3] (1: X = Br; 2: X = I) and [Cu(μ-X)(κP-DAPTA)2]2 (3: X = Br; 4: X = I) were immobilized on activated carbon (AC) and multi-walled carbon nanotubes (CNT), as well as on these materials after surface functionalization. The immobilized copper(I) complexes have shown favorable catalytic activity for the one-pot, microwave-assisted synthesis of 1,2,3-triazoles via the azide-alkyne cycloaddition reaction (CuAAC). The heterogenized systems with a copper loading of only 1.5–1.6% (w/w relative to carbon), established quantitative conversions after 15 min, at 80 °C, using 0.5 mol% of catalyst loading (relative to benzyl bromide). The most efficient supports concerning heterogenization were CNT treated with nitric acid and NaOH, and involving complexes 2 and 4 (in the same order, 2_CNT-ox-Na and 4_CNT-ox-Na). The immobilized catalysts can be recovered and recycled by simple workup and reused up to four consecutive cycles although with loss of activity.

scholarly journals Homo- and Copolymerization of Ethylene with Norbornene Catalyzed by Vanadium(III) Phosphine Complexes

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2088 ◽  
Author(s):  
Giorgia Zanchin ◽  
Alessia Gavezzoli ◽  
Fabio Bertini ◽  
Giovanni Ricci ◽  
Giuseppe Leone
Keyword(s):  
Melting Temperature ◽  
Catalytic Performance ◽  
Phosphine Ligands ◽  
Steric Effects ◽  
Initiation Rate ◽  
Tert Butyl ◽  
Alternating Copolymers ◽  
Phosphine Complexes ◽  
Large Size ◽  
Donor Character

Herein, we report the homo- and co-polymerization of ethylene (E) with norbornene (NB) catalyzed by vanadium(III) phosphine complexes of the type VCl3(PMenPh3-n)2 [n = 2 (1a), 1 (1b)] and VCl3(PR3)2 [R = phenyl (Ph, 1c), cyclohexyl (Cy, 1d), tert-butyl (tBu, 1e)]. In the presence of Et2AlCl and Cl3CCOOEt (ETA), 1a–1e exhibit good activities for the polymerization of ethylene, affording linear, semicrystalline PEs with a melting temperature of approximately 130 °C. Mainly alternating copolymers with high comonomer incorporation were obtained in the E/NB copolymerization. A relationship was found between the electronic and steric properties of the phosphine ligands and the catalytic performance. Overall, the presence of electron-withdrawing ligand substituents increases the productivity, complexes with aryl phosphine (weaker σ–donor character) exhibiting a higher (co)polymerization initiation rate than those with alkyl phosphines (stronger σ–donor character). Steric effects also seem to play a key role since 1d and 1e, having large size phosphines (PCy3 θ = 170° and PtBu3 θ = 182°, respectively) are more active than 1a (PMe2Ph θ = 122°). In this case, the larger size of PtBu3 and PCy3 likely compensates for their higher donor strength compared to PMe2Ph.

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