TY - JOUR
T1 - Porphyrin–Nanodiamond Hybrid Materials—Active, Stable and Reusable Cyclohexene Oxidation Catalysts
AU - Dias, Lucas D.
AU - Rodrigues, Fábio M.S.
AU - Calvete, Mário J.F.
AU - Carabineiro, Sónia A.C.
AU - Scherer, Marisa D.
AU - Caires, Anderson R.L.
AU - Buijnsters, J.G.
AU - Figueiredo, José L.
AU - Bagnato, Vanderlei S.
AU - Pereira, Mariette M.
PY - 2020
Y1 - 2020
N2 - The quest for active, yet “green” non-toxic catalysts is a continuous challenge. In this work, covalently linked hybrid porphyrin–nanodiamonds were prepared via ipso nitro substitution reaction and characterized by X-ray photoelectron spectroscopy (XPS), fluorescence spectroscopy, infrared spectroscopy (IR) and thermogravimetry-differential scanning calorimetry (TG-DSC). The amine-functionalized nanodiamonds (ND@NH2) and 2-nitro-5,10,15,20-tetra(4-trifluoromethylphenyl)porphyrin covalently linked to nanodiamonds (ND@βNH-TPPpCF3) were tested using Allium cepa as a plant model, and showed neither phytotoxicity nor cytotoxicity. The hybrid nanodiamond–copper(II)–porphyrin material ND@βNH-TPPpCF3-Cu(II) was also evaluated as a reusable catalyst in cyclohexene allylic oxidation, and displayed a remarkable turnover number (TON) value of ≈265,000, using O2 as green oxidant, in the total absence of sacrificial additives, which is the highest activity ever reported for said allylic oxidation. Additionally, ND@βNH-TPPpCF3-Cu(II) could be easily separated from the reaction mixture by centrifugation, and reused in three consecutive catalytic cycles without major loss of activity.
AB - The quest for active, yet “green” non-toxic catalysts is a continuous challenge. In this work, covalently linked hybrid porphyrin–nanodiamonds were prepared via ipso nitro substitution reaction and characterized by X-ray photoelectron spectroscopy (XPS), fluorescence spectroscopy, infrared spectroscopy (IR) and thermogravimetry-differential scanning calorimetry (TG-DSC). The amine-functionalized nanodiamonds (ND@NH2) and 2-nitro-5,10,15,20-tetra(4-trifluoromethylphenyl)porphyrin covalently linked to nanodiamonds (ND@βNH-TPPpCF3) were tested using Allium cepa as a plant model, and showed neither phytotoxicity nor cytotoxicity. The hybrid nanodiamond–copper(II)–porphyrin material ND@βNH-TPPpCF3-Cu(II) was also evaluated as a reusable catalyst in cyclohexene allylic oxidation, and displayed a remarkable turnover number (TON) value of ≈265,000, using O2 as green oxidant, in the total absence of sacrificial additives, which is the highest activity ever reported for said allylic oxidation. Additionally, ND@βNH-TPPpCF3-Cu(II) could be easily separated from the reaction mixture by centrifugation, and reused in three consecutive catalytic cycles without major loss of activity.
KW - nanodiamonds
KW - copper (II) porphyrin
KW - allylic oxidation
UR - http://www.scopus.com/inward/record.url?scp=85097216183&partnerID=8YFLogxK
U2 - 10.3390/catal10121402
DO - 10.3390/catal10121402
M3 - Article
SN - 2073-4344
VL - 10
JO - Catalysts
JF - Catalysts
IS - 12
M1 - 1402
ER -