Porphyrin–Nanodiamond Hybrid Materials—Active, Stable and Reusable Cyclohexene Oxidation Catalysts

Lucas D Dias,Vanderlei S Bagnato,Marisa D Scherer,Mário J F Calvete,Sónia A C Carabineiro,Josephus G Buijnsters,Anderson R L Caires,José L Figueiredo,Fábio M S Rodrigues,Mariette M Pereira

doi:10.3390/catal10121402

Abstract

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.

Highlights

The recent advances of nanotechnology are remarkable
We present a study on the cytotoxic on the cytotoxic and genotoxic evaluation of amine-functionalized nanodiamonds (ND@NH2) and 2and genotoxic evaluation of amine-functionalized nanodiamonds (ND@NH2 ) and 2-nitro-5,10,15,20nitro-5,10,15,20-tetra(4-trifluoromethylphenyl)porphyrin covalently linked to nanodiamonds tetra(4-trifluoromethylphenyl)porphyrin covalently linked to nanodiamonds (ND@βNH-TPPpCF3 )
We demonstrated that the β-ipso-nitro-aromatic nucleophilic substitution of amine-functionalized

Summary

Introduction

The recent advances of nanotechnology are remarkable. Nanostructured materials are part of our lives and a driving force towards the global economy of modern society. 22of of 13 examples available, the nanoallotropes of carbon are a unique family, among which nanodiamonds available, nanoallotropes of carbon are a unique family, which nanodiamonds (NDs) are the included. These carbon nanomaterials were first among prepared by detonation in the(NDs). These carbon nanomaterials were first prepared by detonation in the USSR in the [1], the 1960s [1], and have been an exquisite research subject for many groups ever since, attracting and have been an exquisite subject for many ever since, attracting interest, tremendous interest, given research their specific optical and groups physical/chemical propertiestremendous [2].

Objectives

Methods

Results

Conclusion