Zeolite-encapsulated 2-(o-aminophenyl)benzimidazole complexes: synthesis, characterization and catalytic activity.

Autor: Nethravathi, B. P., Mahendra, K. N., Krishna Reddy, K. Rama
Zdroj: Journal of Porous Materials; Jun2011, Vol. 18 Issue 3, p389-397, 9p, 2 Diagrams, 6 Charts, 3 Graphs
Abstrakt: Cobalt(II), copper(II) and zinc(II) complexes of 2-(o-aminophenyl)benzimidazole (AmPhBzlH) encapsulated in the super cages of zeolite-Y and ZSM-5 have been synthesized and characterized by spectroscopic studies (IR, UV/visible, EPR), elemental analyses, thermal studies and X-ray diffraction patterns. The catalytic activity of encapsulated complexes was investigated for the hydroxylation of phenol using 30% HO as an oxidant. Under optimized reaction conditions, the hydroxylation of phenol yielded catechol and hydroquinone as the major products. All catalysts show good selectivity for diphenol products. A maximum conversion of phenol was obtained with [Cu(AmPhBzlH)]-Y as the catalyst. The results showed that conversion of phenol varies in the order [Cu(AmPhBzlH)]-Y > [Cu(AmPhBzlH)]-ZSM-5 > [Zn(AmPhBzlH)]-Y > [Co(AmPhBzlH)]-Y > [Zn(AmPhBzlH)]-ZSM-5 > [Co(AmPhBzlH)]-ZSM-5 after 6 h of reaction time. Test for the recyclability of the reaction was also carried out and the results indicate their recyclability. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index