Spectrophotometric determination of formation constants for the Cu–ethylenediamine–halogen (chloride and bromide) system and their catalytic effect on the oxidative coupling of 2,6-di-tert-butyl-phenol

Segoviano-Garfias, José J. N.; Moreno‐Esparza, Rafael; Mendoza-Dı́az, Guillermo

doi:10.1016/j.ica.2010.06.050

Cited by 9 publications

(4 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…caused splitting of the Cu +2 d orbitals and shifting of the absorption maximum to 850 nm. This phenomena indicates that aminosilane ligand is coordinately bonded to the copper metallic center and is similar with the results presented in [17,18]. For the copper(II) bromide -MAPTMS -2,6-DMP system the band at 850 nm disappeared as a result of the electron transfer from 2,6-DMP to Cu +2 and its reduction to diamagnetic Cu +1 [19].…”

Section: Scheme Bsupporting

confidence: 86%

See 1 more Smart Citation

Application of the copper(II)-aminosilane catalysts in the oxidative polymerization of 2,6-dimethylphenol

et al. 2015

View full text Add to dashboard Cite

The aim of this work was to examine the aminosilane ligands for the copper(II) salts and their application as catalysts for the oxidative polymerization of 2,6-dimethylphenol leading to poly(2,6-dimethyl-1,4-phenylene ether) (PPE) [also known as poly(phenylene oxide) (PPO)] formation. As aminosilane ligands, silane derivatives containing primary and/or secondary amino groups were tested. Among aminosilanes used, PPE was only obtained when N-methylaminopropyltrimetoxysilane (MAPTMS) as a ligand for copper(II) was used. CuCl 2 and CuBr 2 were compared as catalyst precursors for 2,6-dimethylphenol polymerization and influence of N/Cu molar ratio in the range from 80 to 160 on PPE yield and its M w was tested. It was observed, that with increasing N/Cu molar ratio from 80 to 120, both PPE yield and M w increased. PPE with the highest M w was obtained when CuBr 2 -MAPTMS as a catalyst was used. At N/Cu molar ratio equal to 160, a decrease in PPE M w obtained with use of both precursors and decrease in PPE yield for CuCl 2 -MAPTMS catalyst were noticed. The condensed nanoorganosilicon particles of spherical shape well dispersed in PPE were determined in the polymer matrix. The UV-Vis studies showed that, strong ligand field of the aminosilane ligand easier electron transfer from monomer to Cu(II) and thus polymerization facilitate.

show abstract

Section: Scheme Bsupporting

confidence: 86%

“…Aminosilane and anhydrous ethanol UV-Vis spectrum was omitted. For the copper(II) bromide in ethanolic solution an absorption maximum appeared at 914 nm [17], as a result of the low-energy electron transfer within d subshell -characteristic for Cu(II) square planar complex structure [16].…”

Section: Uv-vis Spectroscopic Studiesmentioning

confidence: 99%

Application of the copper(II)-aminosilane catalysts in the oxidative polymerization of 2,6-dimethylphenol

et al. 2015

View full text Add to dashboard Cite

show abstract

“…However, the nature of the rate-determining step can be catalyst-dependent. 720 In the presence of protic solvents the dimer formed initially undergoes further reaction, generating either an oxetane 711 and or a furan tricycle 714 (Scheme 404). Interestingly, substitution at the meta -position prevents this additional oxidation step.…”

Section: Reactions Of Phenols and Naphtholsmentioning

confidence: 99%

“…Note that the peroxide-bridged diradical species is unstable and likely undergoes rapid fragmentation to the copper(II) complex. However, the nature of the rate-determining step can be catalyst-dependent . In the presence of protic solvents the dimer formed initially undergoes further reaction, generating either an oxetane or a furan tricycle (Scheme ).…”

Section: Reactions Of Phenols and Naphtholsmentioning

confidence: 99%

Aerobic Copper-Catalyzed Organic Reactions

et al. 2013

View full text Add to dashboard Cite

24 peroxide [Cu I (pyr)(tpb)] 10 mol % TBHP, 1 atm O 2 , 1:2 AcOH/pyr, rt, 24 h ∼2.5 26 74 g 35 25 n-hexane aldehyde CuCl 2 , 18-crown-6 1 atm O 2 , MeCHO, CH 2 Cl 2 , 70 °C, 24 h 2.4 91 h 9 34a 26 n-decane aldehyde Cu II Cl 16 Pc-AM(PS) 3 equiv of PhCHO, MeCN, 1 atm O 2 , 50 °C 15.4 100 i 61 a See Chart 2 for ligand structures. b Also 28% cyclohexene. c Also 26% cyclohexene. d Mixture of alcohol and hydroperoxide. e Remainder of product is cyclohexene. f Approximately 93:7 of 1-adamantol/2-adamantol. g Approximately 98:2 of 1-adamantol/2-adamantol. h Afforded oxidation products in an approximately 1:1 ratio at the 2-and 3-positions. i Mixture of decanones.

show abstract

Oxidative polymerization of 2,6‐dimethylphenol to form poly(2,6‐dimethyl‐1,4‐phenylene oxide) in water through one water‐soluble copper(II) complex of a zwitterionic calix[4]arene

Wan

Zhao

et al. 2012

J. Polym. Sci. A Polym. Chem.

View full text Add to dashboard Cite

In the presence of excess NaOH, reaction of Cu(OAc) 2 ÁH 2 O with equimolar ammonium calix[4]arene [H 4 L]I 4 (1, H 4 L ¼ [5,11,17,23-tetrakis(trimethylammonium)-25,26,27,28tetrahydroxycalix[4]arene]) resulted in the formation of a mononuclear cationic Cu(II) complex [Cu(II)L(H 2 O)]I 2 (2) in 43% yield. Complex 2 was characterized by elemental analysis, infrared (IR), and single crystal X-ray diffraction. The Cu(II) atom in 2 is coordinated by four oxygen atoms of one L 4À ligand and one O atom from one water molecule, forming a square pyramidal geometry. Complex 2 exhibited high catalytic activity in the oxidative polymerization of 2,6-dimethylphenol using O 2 as oxidizing agent in water under mild conditions. The selective polymerization produced poly(2,6-dimethyl-1,4phenylene oxide) in high yields with almost no diphenoquinone. The influence of the polymerization temperature, the time interval, the molar ratio of 2,6-dimethylphenol/2, the concentrations of sodium hydroxide, and sodium n-dodecyl sulfate were examined. V C 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: [4864][4865][4866][4867][4868][4869][4870] 2012

show abstract

Spectrophotometric determination of formation constants for the Cu–ethylenediamine–halogen (chloride and bromide) system and their catalytic effect on the oxidative coupling of 2,6-di-tert-butyl-phenol

Cited by 9 publications

References 18 publications

Application of the copper(II)-aminosilane catalysts in the oxidative polymerization of 2,6-dimethylphenol

Application of the copper(II)-aminosilane catalysts in the oxidative polymerization of 2,6-dimethylphenol

Aerobic Copper-Catalyzed Organic Reactions

Oxidative polymerization of 2,6‐dimethylphenol to form poly(2,6‐dimethyl‐1,4‐phenylene oxide) in water through one water‐soluble copper(II) complex of a zwitterionic calix[4]arene

Contact Info

Product

Resources

About