107035-15-4Relevant academic research and scientific papers
Facile Mechanochemical Anion Substitution in Cyclopalladated Azo-Benzenes
Bjelopetrovi?, Alen,Robi?, Marko,Halasz, Ivan,Babi?, Darko,Juriba?i? Kulcsár, Marina,?uri?, Manda
, p. 4479 - 4484 (2019)
The solvent-free ball-milling method for substitution of anionic ligands in organopalladium compounds was developed. Reactions of acetate, acetylacetonate, chloride, or tetrafluoroborate of mono- or dicyclopalladated azobenzenes with alkali salts of chloride, acetate and acetylacetonate yielded target products, some of which could not be obtained via direct C-H bond activation by Pd(II) precursors. The formation of products was monitored in situ by Raman spectroscopy and ex situ by NMR and IR spectroscopies and PXRD. The reported solid-state pathway provides easy access to organopalladium derivatives in high yields and in shorter reaction times than solvent-based protocols.
Competition between 3d metals(II) and palladium(II) in the reaction of heterobimetallic complexes Pd(μ-OOCMe)4M(OH2) (M = Ni, Co, Mn) with azobenzene
Nefedov, Sergei E.,Perova, Elena V.,Yakushev, Ilya A.,Kozitsyna, Natalia Yu.,Vargaftik, Michael N.,Moiseev, Ilya I.
, p. 454 - 456 (2009)
The reaction of PdII(μ-OOCMe)4MII(OH2) (M = Ni, Co, Mn) with azobenzene under mild conditions produces the homonuclear complex with ortho-metallated azobenzene (PhN = NC6H4)2Pds
Aerobic Photooxidation and C-C Bond Cleavage of the Acetylacetonate Ligand in (2-Arylazo)arylpalladium(II) Complexes Induced by Visible Light
Vicente, Jose,Arcas, Aurelia,Bautista, Delia,Shul'pin, Georgiy B.
, p. 1505 - 1510 (2007/10/02)
(Arylazo)aryl(acetylacetonato)palladium(II) complexes, (R = H 1a, Me 1b or OMe 1c; Hacac = acetylacetone), upon irradiation of their acetone solutions at room temperature by UV, or even long-wavelength visible (λ > 500 nm) light, were readily oxidized by atmospheric oxygen to give the corresponding acetato derivatives 2 (R = H 2a, Me 2b or OMe 2c), providing a model for some chemical and biological processes.The oxidation reaction of complex 1b was first order in the complex 0 -3.Complexes 1b and 1c were photooxidized at approximately twice the rate of complex 1a.In the presence of a scavenger of C-centred radicals (CCl4) the rate of complex 2b accumulation was reduced.When pyridine was added or co-ordinating solvents (acetonitrile or nitromethane) were used no photooxidation of comlex 1 occured.In the presence of PPh3 an induction period was observed and the oxidation of 1 strted only after all the PPh3 was oxidized under irradiation into OPPh3.Spectroscopic data suggested that these ligands inhibit this photochemical oxidation because they change the type of co-ordination of the azobenzene chromophore and/or the acac ligands inducing a disconnection between the chromophore (antenna) and the acac ligand.
Thermodynamics, kinetics, and mechanism of exchange of cyclopalladated ligands
Ryabov, Alexander D.
, p. 1252 - 1260 (2008/10/08)
The exchange between cyclopalladated complexes and free ligands has been studied in acetic acid. An equilibrium study of the system based on N,N-dimethylbenzylamine derivatives [PdX(YZC6H2CH2NMe2)]2 + 2C6D5CD2NMe2 ? [PdX-(C6D4CD2NMe2)]2 + 2YZC6H2DCH2NMe2 (K1) has revealed that Pd(II) binds preferably with the electron-poorest ligand at equilibrium; K1 is 114, 0.59, 0.125, 0.008, and 0.0034 for 4-Y (5-Z) = MeO (MeO), H (Me), H (H), H (Cl), and H (NO2), respectively, at 55°C in D3CCOOD/CDCl3, X = MeCO2-. A procedure for regioselective ortho palladation of bifunctional derivatives such as 1-(3,4-dimethoxyphenyl)-2-methyl-3-(4-nitrophenyl)-2-azapropane (7) is put forward. In aprotic chloroform, Pd(II) acetate metalates the electron-rich ring of 7 to yield 8a, but the electron-poor ring is ortho palladated in acetic acid to yield 9a. A dissociative exchange mechanism is proposed on the basis of a kinetic study of reactions between [PdX-(YZC6H2CH2NMe2)]2 and 2-phenylpyridine or azobenzene to afford the corresponding cyclopalladated complexes. Preequilibrium measurements have indicated that in the former case the reactive species are monomers formed via acetate-bridge cleavage by 2-phenylpyridine but in the latter case the complexes react as dimers. Despite this, all of the reactions are first order in complex and zero order in entering ligand. The rate constants of the 2-phenylpyridine case at 75°C are (104k) 12.6, 3.9, 2.35, 2.6, 0.44, and 0.0225 s-1 for 4-Y (5-Z) = MeO (MeO), H (Me), H (H), H (MeO), H (Cl), and H (NO2), respectively. On the basis of substituent and solvent kinetics isotope effects, values of activation parameters, and data obtained previously, it has been suggested that cleavage of the Pd-N bond of the leaving ligand occurs first, followed by acidolysis of the Pd-C bond. Both steps can contribute to the overall rate. The two are followed by the rapid activation of the C-H bond of the incoming ligand. Reasons for the pseudonucleophilic behavior of Pd(II) toward C-H bonds of benzylamines in acetic acid have been evaluated on the basis of the proposed mechanism.
