Artículo de revista
Cu(H(2)btec)(bipy)](infinity): a novel metal organic framework (MOF) as heterogeneous catalyst for the oxidation of olefins
Fecha
2009Autor
Brown, Kareen
Zolezzi Carvallo, Santiago
Aguirre, Pedro
Venegas Yazigi, Diego
Paredes García, Verónica
Baggio, Ricardo
Novak, Miguel
Spodine Spiridonova, Evgenia
Institución
Resumen
A new extended metal-organic framework [Cu(H(2)btec)(bipy)](infinity) (1) (H(4)btec=1,2,4,5-benzenetetracarboxylic acid; bipy= 2,2'-bipyridine) has been hydrothermally synthesized. Violet crystals are formed in a monoclinic system with a space group C2/c; a = 10.1810(18) angstrom, b = 14.4360(18) angstrom, c= 12.894(3) angstrom, beta= 112.94(3)degrees. In the title compound 1 each Cu(II) centre has a distorted square planar environment, completed by two N atoms from one bipy ligand and two O atoms belonging to two dihydrogen benzene-1,2,4,5-tetracarboxylate anions (H(2)btec(2-)). The {Cu(bipy)}(2+) moieties are bridged by H(2)btec(2-) anions to form an infinite one-dimensional coordination polymer with a zig-zag chain structure along the c axis. A double-chain structure is formed by hydrogen bonds between adjacent zig-zag chains. There are also p-p stacking interactions between the bipy ligands, with an average distance of 3.62 angstrom resulting in a two-dimensional network structure. Compound 1 was tested as a catalyst for the oxidation of cyclohexene and styrene, with tert-butyl hydroperoxide (TBHP) as oxidant. The catalytic activity (24 h and 75 degrees C) found for [Cu(H(2)btec)(bipy)](infinity) shows a high value for the conversion of cyclohexene (64.5%), and a lower one for styrene (23.7%). High turnover frequency (TOF) values for the epoxide products were observed, indicating that the catalyst synthesized in this work, not only has a high activity and selectivity for epoxidation reactions but is also very efficient.