abstract
Two new 3D metal-organic frameworks (MOF), [Co(H-2-DHBDA)(bpe)](n) (1) and [Co(H-2-DHBDA)(bpee)](n) (2) [H-2-DHBDA = 2,5-dihydroxy-1,4-benzenediacetate, bpe = 1,2-bis(4-pyridyl)ethylene, bpee = 1,2-bis(4-pyridyl)ethane], were synthesized hydrothermally. Both compounds have a similar 3D structure. The secondary building unit is a Co-2 dimer with a CoCo distance of 4.02 angstrom. The hydroxy groups remain free on the surface of the compounds, and they participate in the intramolecular hydrogen bonding. A detailed structural analysis revealed that the structure is a 7-c uninodal net with the Schlafli symbol 3(3).4(13).5(4).6 and the vertex symbol [3.3.3.4.4.4.4.4.4.4.4.4.4.4.4.*.*.*.*.*.*]. The compound is catalytically active towards epoxidation reactions in heterogeneous medium with H2O2 as an oxidant. They catalyze the epoxidation of almost all types of olefinic substrates with good efficiency. After the reaction, the catalysts can be recovered quite easily, and they can be used for further reactions without any loss of activity for several cycles.
keywords
HETEROGENEOUS CATALYTIC-OXIDATION; X-RAY-STRUCTURE; MOLECULAR-OXYGEN; MAGNETIC-PROPERTIES; CRYSTAL-STRUCTURES; HYDROTHERMAL SYNTHESIS; SELECTIVE OXIDATION; HYDROGEN-PEROXIDE; ASYMMETRIC DIHYDROXYLATION; PRACTICAL METHOD
subject category
Chemistry
authors
Sen, R; Saha, D; Mal, D; Brandao, P; Lin, Z
our authors
Paula Cristina Ferreira da Silva Brandão
Assistant Researcher
Zhi Lin
Principal Researcheracknowledgements
R. S. thanks the Fundacao para a Ciencia e a Tecnologia (FCT) for a postdoctoral fellowship (SFRH/BPD/71798/2010). This work was also financially supported by the Programa Operacional Ciencia e Inovacao 2010 (POCI2010), the Fundo Social Europeu (FSE) and the Fundo Europeu de Desenvolvimento Regional (FEDER).