resumo
2-(4H-1,2,4-triazol-4-yl)acetic acid (trglyH) and (dl)-4-methyl-2-(4H-1,2,4-triazol-4-yl)pentanoic acid (trleuH) were used as ligands for the development of MoO3 coordination hybrids for catalytic applications. Coordination polymers [Mo2O6(Htrgly)] . H2O (1) and [MoO3(trleuH)] . 0.5H(2)O (2) were prepared and structurally characterized. Compound 1 adopts a structure in which edge-sharing MoO6 octahedra are organized in a ribbon motif via mu(3)-O bridges. The Htrgly ligand exists as a zwitterion: -CO2- links two Mo-VI in a mu(2)-eta(1) : eta(1) mode, while positively charged triazolium is left uncoordinated. In 2, Mo atoms are joined in a chain through mu(2)-O. The more hydrophobic trleuH appears in a nonionized form and its [N-N] sites serve as a clamp for supporting the [-OMo(O)(2)-OMo(O)(2)(tr)(2)](n) sequence. The complexes were explored for liquid phase catalytic epoxidation of cis-cyclooctene, using H2O2 or tert-butylhydroperoxide as oxidants. The hybrids showed good catalytic activity, and 2 behaved as a reaction-induced self-separating catalyst for olefin epoxidation with H2O2, presenting advantages of homogeneous and heterogeneous catalysis.
palavras-chave
STRUCTURAL ELUCIDATION; OLEFIN EPOXIDATION; OXIDATION; COMPLEXES; BEHAVIOR
categoria
Chemistry, Physical
autores
Lysenko, AB; Senchyk, GA; Domasevitch, KV; Neves, P; Valente, AA; Pillinger, M; Goncalves, IS
nossos autores
Projectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Conversao catalitica de olefinas derivadas da biomassa (BiOle_AcidOxCat)
agradecimentos
This work was supported by the National Research Foundation of Ukraine (Project no. 2020.02/0071). The Portuguese (PT) group acknowledge funding provided within the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, and COMPETE 2020 Operational Thematic Program for Competitiveness and Internationalization (Project POCI-01-0145-FEDER-030075), financed by national funds through the FCT (Fundacao para a Ciencia e a Tecnologia)/MEC (Ministerio da Educacao e Ciencia) and when appropriate co-financed by the European Union through the European Regional Development Fund under the Portugal 2020 Partnership Agreement. The position held by P.N. was 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.