Host (nanocavity of zeolite-Y)-guest (tetraaza[14]annulene copper(II) complexes) nanocomposite materials: Synthesis, characterization and liquid phase oxidation of benzyl alcohol

Copper(II) complexes with tetraaza[14]annulene ligands 5,7,12,14-tetramethyldibenzo-1,4,8,11-tetraazacyclotetradecine [Cu(Me(4)R(2)Bzo[14]tetraeneN(4))] (R=H, CH3, Cl and NO2) have been prepared from the one-pot template condensation reaction of substituted-1,2-phenylenediamine (4-methyl-; 4-chloro-; 4-nitro-1,2-phenylenediamine) with 2,4-pentanedione in the presence of copper(II) ion within the nanocavity pores of zeolite-Y [Cu(Me(4)R(2)Bzo[14]tetraeneN(4))]-NaY. The new materials were characterized by several techniques: chemical analysis and spectroscopic methods (FT-IR, UV/vis, XRD, BET and DRS). The analytical data indicated a composition corresponding to the mononuclear complex of tetraaza[14]annulene. The characterization data showed the absence of extraneous complexes, retention of zeolite crystalline structure and encapsulation in the nanocavities. Encapsulated copper(II) complex is catalytically very efficient as compared to other neat complexes for the partial oxidation of benzyl alcohol and is stable to be recycled without much deterioration. (c) 2005 Elsevier B.V. All rights reserved.