resumo
The development of selective, efficient, and recoverable/reusable catalysts for oxidation reactions has become one of the main challenges of modern chemistry. Considering our interest in efficient catalytic systems based on porphyrin (Por) and phthalocyanine (Pc) coordination polymers, we report here the synthesis, characterization and catalytic activity of a new Pc coordination polymer (coined hereafter as Cu4CuPcSPy). The new Pc material was obtained in excellent yield, from the reaction of H2PcSPy with an excess amount of copper(ii) acetate. The catalytic efficiency of Cu4CuPcSPy was evaluated in the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) in the presence of molecular oxygen from air, with or without the addition of aqueous 30% hydrogen peroxide. The comparison between the homogeneous (CuPcSPy) and the heterogeneous (Cu4CuPcSPy) catalytic systems showed a better performance for the Cu4CuPcSPy material, that can be recovered by filtration and reused, maintaining its activity roughly unchanged during three catalytic cycles. An increment of approximately 30% was also verified in the catalytic activity of the homogeneous and heterogeneous systems by adding aqueous hydrogen peroxide to the catalytic reactions.
palavras-chave
METAL-FREE; METALLOPORPHYRIN DERIVATIVES; PORPHYRINS; OXIDATION; PROMISCUITY; COMPLEXES; NETWORK; MODELS; LIGHT; WATER
categoria
Chemistry
autores
Castro, KADF; Figueira, F; Paz, FAA; Tome, JPC; da Silva, RS; Nakagaki, S; Neves, MGPMS; Cavaleiro, JAS; Simoes, MMQ
nossos autores
Filipe Alexandre Almeida Paz
Investigador Principal
Flávio Alberto da Silva Figueira
Investigador Júnioragradecimentos
This work was funded by national funds (OE), through FCT - FundacAo para a Ciencia e a Tecnologia, I. P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19 (REF.-168 - 89-ARH/2018). Thanks are due to Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), CoordenacAo de Aperfeicoamento de Pessoal de Nivel Superior (CAPES), FundacAo de Amparo a Pesquisa do Estado de SAo Paulo (FAPESP-2016/12707-0), Universidade de SAo Paulo. We also, wish to thank FundacAo para a Ciencia e a Tecnologia (FCT) for the financial support to QOPNA (FCT UID/QUI/00062/2019), CICECO (POCI-01-0145-FEDER-007679; UID/CTM/50011/2019) and CQE (1801P.00912.1.01; FCT UID/QUI/0100/2019) research units, through national funds and where applicable co-financed by FEDER, within the PT2020 Partnership Agreement. K. A. D. F. Castro thanks CNPq for the post-doctoral scholarship granted (Process 201107/2014-7) and PNPD/CAPES. We would like to thank Dr Marcia A. M. S. Veiga and Luiza C. Pomarolli from the Chemistry Department at USP/RibeirAo Preto for atomic absorption measurements and Dr Juliana C. Biazzotto from the Pharmaceutical Sciences School at the University of SAo Paulo for technical assistance in cyclic voltammetry studies.