Encapsulation of copper(II) complexes with pentadentate N3O2 Schiff base ligands derived from acetylacetone in NaX zeolite

Copper(II) complexes with two five co-ordinate Schiff base ligands derived from acetylacetone and which provide a N3O2 co-ordination sphere, bis(acety lacetonate)-3-amino-bis(propyldiimine) and bis(acetylacetonate)-3-methylami no-bis(propyldiimine), were entrapped in the supercages of zeolite NaX by a two-step process in the liquid phase: (i) adsorption of copper(II) acetyla cetonate in the supercages of the zeolite, and (ii) in situ Schiff condensa tion of the copper(II) precursor complex with the corresponding triamines. The new materials were characterised by several techniques: chemical analys is, morphological and surface analysis, spectroscopic methods (FTIR, UV/VIS ) and electron paramagnetic resonance. Analysis of the data indicates that the Cu(II) complexes are encapsulated in the NaX zeolite supercages and exh ibit structural and electronic properties that are different from those of the free complexes, which can arise from distortions caused by steric effec ts due to the presence of sodium cations, or from interactions with the zeo lite matrix. (C) 2000 Elsevier Science B.V. All rights reserved.