Autoxidation of some phenols catalyzed by ring-substituted salcomines

Tomaja, D. L.; Vogt, Lester H.; Wirth, J. G.

doi:10.1021/jo00831a071

Cited by 47 publications

(12 citation statements)

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“…Cobalt(I1) Schiff-base complexes are known to be effective catalysts in autoxidation of phenols [15][16][17][18][19][20][21][22][23][24][25][26][27]. Oxidation of phenols is not only of synthetic importance but they are also implicated in many biogenetic pathways 15).…”

Section: Introductionmentioning

confidence: 99%

Studies of the autoxidation of phenols catalyzed by the cobalt(II) complex of disodium N,N′‐bis(salicylidene)‐ethylenediamine‐5,5′ ‐disulfonate bound to colloidal anion exchange resin

et al. 1993

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To overcome mass transfer limitations which are usually encountered on immobilizing active catalysts, cationic latex particles were used as support for the cobalt(I1) complex of disodium N,hP-bis(salicylidene)ethylenediamine-5,5'-disulfonate (1). The cationic latex 2 was prepared by emulsion copolymerization of chloromethylstyrene (m/p-isomer mixture 60/40) and divinylbenzene (m/p-isomer mixture) followed by treatment with trimethylamine. The latexbound catalyst from 1 and 2 was found to considerably increase the reaction rate of the autoxidation of 2,6-di-tert-butylphenol in water as compared with the conventional polymer-free system. Reaction products were identified as the oxidative coupling product 3,3',5,5'-tetratert-butyldiphenoquinone (3,3',5,5'-tetra-ter~-butyl-4,4'-dioxo-l,l'-bicyclohexa-2,5-dieny~idene) and 2,6-di-tert-butyl-1,4-benzoquinone. All reactions showed an induction period before the start of dioxygen consumption. The rate of autoxidation in the three-phase mixtures of water, latex particles, and phenol droplets was not affected significantly by the method of mixing. The reaction rate increased as the concentration of 1 increased. Increasing the partial pressure of dioxygen in the range between 0,25 and 1,0 atm (2,53 . lo4 -1,Ol . 10' Pa) gave a small increase in rate. The colloidal latex catalyst from 1 and 2 showed some loss of activity after successive runs. 0 1993, Huthig & Wepf Verlag, Basel CCC 0025-1 16X/93/$05.00

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Section: Introductionmentioning

confidence: 99%

Studies of the autoxidation of phenols catalyzed by the cobalt(II) complex of disodium N,N′‐bis(salicylidene)‐ethylenediamine‐5,5′ ‐disulfonate bound to colloidal anion exchange resin

et al. 1993

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“…The axial ligation costants and thermodynamic parameters for these types of macrocyclic complexes have already been reported. [3][4][5][6] The catalytic oxidation of methyl hydroquinone by tetramethyl tetraaza cobalt macrocyclic complexes has also been reported. [7][8][9][10][11][12] We carried out the autooxidation of methoxy and some other hydroquinones in presence of Co(II) and Mn(II) complexes of hexamethyl tetraaza macrocyclic ligands A and B.…”

Section: Introductionmentioning

confidence: 99%

Studies of Synthetic Macrocyclic Complexes of Co (II) and Mn( II) in the Catalytic Oxidation of Hydroquinones

Tevatia¹,

Sweety²,

Anuj³

et al. 2014

IOSRJAC

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“…Metal complexes have been observed to have a variety of structures. Copper(II)/ N ‐ligand complexes17–21 and N ‐ligand/transition‐metal/phenolate complexes,22–35 in which imidazoles and pyrazoles are used as the N ‐ligands, have been widely synthesized and characterized. Copper(II) complexes of the type L n Cu (phenolato) 2 (where L is a chelating N ‐ligand with n = 1 and a nonchelating N ‐ligand with n = 2 and phenolato is a phenolate substituted by halogens in the 2,4,6‐positions or methoxy or nitro groups in the 2‐ or 4‐positions)24–28, 31–36 are especially attractive because they are either studied as model systems for coordination in metalloproteins or decomposed to yield poly(dihalophenylene oxide)s.…”

Section: Introductionmentioning

confidence: 99%

Effect of N‐methylimidazole and 3,5‐dimethylpyrazole ligands on the polymerization of di(2,6‐dichlorophenolato) Cu(II)/Co(II) complexes in the solid state

Baştürkmen

Hacaloğlu

Kisakürek

2004

J of Applied Polymer Sci

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The polymerization of 2,6-dichlorophenol (DCPH) was achieved through the thermal decomposition of copper complexes of DCPH with N-methylimidazole (NMIz) and 3,5-dimethylpyrazole (DMPz) ligands. Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), mass spectrometry, ultraviolet-visible spectroscopy, diffuse reflectance spectroscopy, magnetic susceptibility balance, electron spin resonance, X-ray analysis, and elemental analysis were used to characterize the complexes. The polymerization was achieved either in the solid state or in the melt. The structural analyses were performed with FTIR and NMR spectroscopy analyses. The glass-transition temperatures were determined by DSC, and the intrinsic viscosities were determined by viscosimetry. The effects of the temperature and time on the conversion percentage and viscosity of the polymers were examined. Varying the decomposition temperature during a 3-h scan showed that the DMPz complex of Cu decomposed at lower temperatures than the NMIz complex, whereas the NMIz complex yielded a higher conversion to the polymer. Complexes of DCPH with NMIz and DMPz ligands produced 1,2-and 1,4-addition products, respectively.

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Autoxidation of some phenols catalyzed by ring-substituted salcomines

Cited by 47 publications

References 0 publications

Studies of the autoxidation of phenols catalyzed by the cobalt(II) complex of disodium N,N′‐bis(salicylidene)‐ethylenediamine‐5,5′ ‐disulfonate bound to colloidal anion exchange resin

Studies of the autoxidation of phenols catalyzed by the cobalt(II) complex of disodium N,N′‐bis(salicylidene)‐ethylenediamine‐5,5′ ‐disulfonate bound to colloidal anion exchange resin

Studies of Synthetic Macrocyclic Complexes of Co (II) and Mn( II) in the Catalytic Oxidation of Hydroquinones

Effect of N‐methylimidazole and 3,5‐dimethylpyrazole ligands on the polymerization of di(2,6‐dichlorophenolato) Cu(II)/Co(II) complexes in the solid state

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