A NOVEL TRICLINICALLY DEFORMED CHABAZITE-LIKE ALUMINOPHOSPHATE PREPARED IN THE PRESENCE OF TRIS(1,2-DIAMINOETHANE) NICKEL(II) CHLORIDE

The tris(1,2-diaminoethane) nickel(II) complex was found to be a novel structure-directing agent for the preparation of the chabazite-like A lPO4-34 molecular sieve. During crystallization the complex undergoes a ligand exchange, thus helping stabilization of the AlPO4's chabazite structure by hydroxyls that have exchanged one 1,2-diaminoethane (en) molecule from the Ni(II) coordination sphere. The exchanged complex, [Ni(en)(2)(OH)(2)], remains in the chabazite host causing a triclinic deformation of the rhombohedral chabazite framework. Upon calcination the triclinic phase completely transforms into the rhombohedral chabaz ite-like AlPO4-34 as evidenced from the in situ XRD pattern. (C) 1998 Elsevier Science B.V. All rights reserved.