abstract
The complex [MoO(O-2)(2)(pyrazole)(2)] (1) is an effective catalyst for the oxidation of organic sulfides (methyl-phenylsulfide and diphenylsulfide). Reactions can be run in water as the only medium, at low temperature (25 degrees C), with low catalyst loadings (0.2 mol%) and excellent H2O2 efficiency with no significant non-productive decomposition of the oxidant. Under conditions that favor sulfone formation, the overall process, including isolation of the precipitated product (by filtration or centrifugation) and recycling of the aqueous phase con-taining the catalyst, can be performed in the absence of organic or ionic liquid solvents. Catalytic results with the recycled aqueous phase were the same as those obtained in the first cycle. With water as the sole solvent, 1 is a superior catalyst to the 3,5-dimethylpyrazole complexes [MoO(O-2)(2)(dmpz)(2)] (2) and [Hdmpz](4)[Mo8O25.8(O-2)(0.2)(dmpz)(2)]center dot 4H(2)O (3). Crystal structures for 1 and 3 are presented.
keywords
MOLYBDENUM(VI) COMPLEXES; MOLECULAR-STRUCTURE; METAL DERIVATIVES; OXYGEN-TRANSFER; SULFOXIDES; CHEMISTRY; PYRAZOLE; CRYSTAL; POLY(PYRAZOLYL)ALKANES; COORDINATION
subject category
Chemistry
authors
Bruno, SM; Amarante, TR; Paz, FAA; Pillinger, M; Valente, AA; Goncalves, IS
our authors
Anabela Tavares Aguiar Valente
Principal Researcher
Isabel Maria de Sousa Gonçalves
Associate Professor
Sofia M. Bruno
Assistant Researcheracknowledgements
This work was carried out with the support of CICECO - Aveiro Institute of Materials [FCT (Fundacao para a Ciencia e a Tecnologia) Ref. UIDB/50011/2020 & UIDP/50011/2020] and the COMPETE 2020 Operational Thematic Program for Competitiveness and Internationalization (Project POCI-01-0145-FEDER-030075), co-financed by national funds through the FCT/MCTES and the European Union through the European Regional Development Fund under the Portugal 2020 Partnership Agreement. The positions held by S.M.B. and T.R.A. were funded by national funds (OE), through FCT, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of article 23 of the Decree-Law 57/2016 of 29 August, changed by Law 57/2017 of 19 July.