Oxidation of 2,6-di-tert-butylphenol with tert-butylhydroperoxide catalyzed by cobalt(II) phthalocyanine tetrasulfonate in a methanol-water mixture and formation of an unusual product 4,4 '-dihydroxy-3,3 ',5,5 '-tetra-tert-butylbiphenyl


Turk H., Cimen Y.

JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL, cilt.234, sa.1-2, ss.19-24, 2005 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 234 Sayı: 1-2
  • Basım Tarihi: 2005
  • Doi Numarası: 10.1016/j.molcata.2005.02.022
  • Dergi Adı: JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.19-24
  • Anahtar Kelimeler: 2,6-di-tert-butylphenol, 3,3 ',5,5 '-tetra-tert-butyl-4,4 '-diphenoquinone, 4,4 '-dihydroxy-3,3 ',5,5 '-tetra-tert-butylbiphenyl, cobalt(II) phthalocyanine tetrasulfonate, tert-butylhydroperoxide, oxidation, METALLOPHTHALOCYANINE FUNCTIONALIZED SILICAS, LIQUID-PHASE OXIDATION, MOLECULAR-OXYGEN, AROMATIC-COMPOUNDS, HYDROGEN-PEROXIDE, SELECTIVE OXIDATION, AEROBIC OXIDATION, METALLOMACROCYCLES, AUTOXIDATION, COMPLEXES
  • Anadolu Üniversitesi Adresli: Hayır

Özet

The oxidation of 2,6-di-tert-butylphenol (DTBP) with tert-butylhydroperoxide (Bu'OOH) catalyzed by cobalt(II) phthalocyanine tetrasulfonate ([CoPcTS](4-)) in a 4:1 methanol-water mixture gave predominantly the coupled products 3,3',5,5'-tetra-tert-butyl-4,4'-diphenoquinone (DPQ) and 4,4'-dihydroxy-3,3',5,5'-tetra-tert-butylbiphenyl (H(2)DPQ) when the oxidant/substrate ratio was less than 10. The conversion of DTBP was 70 % in 3 h and 86 % in 8 h when the amounts of DTBP, Bu'OOH, and [CoPcTS](4-) in millimoles were 0.300, 1.52, and 3.0 x 10(-3), respectively. The yield of DPQ was 56 % in 3 h and 73 % in 8 h whereas that of H(2)DPQ was about 14 % in 3 and 8 h. H(2)DPQ is not commonly encountered the oxidation product of DTBP and is considered unstable. When the oxidant/substrate ratio was over 10, 2,6-di-tert-butylbenzoquinone was also formed. The degradation of [CoPcTS](4-) by Bu'OOH also occurred during the oxidation of DTBP. About three-fourths of the catalyst was degraded in the first hour and about 2 % of the catalyst remained after 8 h. (c) 2005 Elsevier B.V. All rights reserved.