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The location of Cu(II) and its interaction with deuterated adsorbates in Cu(II)-exchanged gallosilicate with the offretite channel-type structure were investigated by electron spin resonance (ESR) and electron spin echo modulation (ESEM) spectroscopies. It is suggested that in fresh, hydrated offretite gallosilicate Cu(II) is in the main channel coordinated to three water molecules and three framework oxygens in a six-ring window of an ε-cage to form distorted octahedral coordination. Upon evacuation at increasing temperature, Cu(II) moves from the main channel through an ε-cage to a hexagonal prism. Dehydration at 400 °C produces one Cu(II) species located in a recessed site in a hexagonal prism based on a lack of broadening of its ESR lines by oxygen. Adsorption of polar molecules such as water, alcohols, dimethyl sulfoxide, and ammonia causes changes in the ESR spectrum of the Cu(II), indicating migration into cation positions in the main channels where adsorbate coordination can occur. However, nonpolar ethylene does not cause migration of Cu(II). Cu(II) forms complexes with two molecules of methanol, ethanol, and propanol and one molecule of dimethyl sulfoxide based on ESEM data. Cu(II) is suggested to form a trigonal-bipyramidal complex with two ammonias in axial positions and three framework oxygens in a six-ring window of an ε-cage based on its ESR parameters and ESEM data.

The interaction of Cu" with deuteriated adsorbates in Cu"-exchanged gallosilicate with the zeolite L channel-type structure has been investigated by EPR and electron spin echo modulation (ESEM) spectroscopies, and compared with that in Cu"-exchanged K-L aluminosilicate zeolite. Similar results to those for CUK-L aluminosilicate were observed in CuK-L gallosilicate. It was found that, in the fresh hydrated material, Cu" is octahedrally coordinated to six water molecules. This species is located in the main channels and rotates rapidly at room temperature. A minor Cu" diaquo species seen in the aluminosilicate is not observed in the gallosilicate. Evacuation at room temperature removes three of these water molecules, leaving the Cu" coordinated to three water molecules and anchored to the zeolite lattice by coordination to zeolitic oxygens in an eight-ring; the coordinated water is removed more easily in the gallosilicate than in the aluminosilicate. Upon further evacuation at increasing temperature, Cu" moves from the main channel towards recessed sites. Dehydration at 400 "C produces one Cu" species located in recessed sites, as evidenced by a lack of broadening of its EPR lines by oxygen. Adsorption of polar molecules such as water and alcohols causes changes in the EPR spectrum of the Cu" indicating migration into the main channels where adsorbate coordination can occur. Ethene also coordinates with Cu" but causes less migration. Cu" forms complexes with two molecules of methanol and ethanol, and with one molecule of ethene, as evidenced by ESEM data, which is the same as for Cu" in CuK-L aluminosilicate zeolite.

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