Crystal Structures of Vacuum Dehydrated Fully $Cd^{2+}$-Exchanged Zeolite A and Its Ethylene Sorption Complex

Abstract

The crystal structure of dehydrated fully $Cd^{2+}$-exchanged zeolite A evacuated at Torr and $450^{\circ}C (a = 12.225(2){\AA})$ and of its ethylene sorption complex (a = 12.219(2) ${\AA}$) have been determined by single crystal X-ray diffraction techniques in the cubic space group Pm3m at . The structures were refined to final error indices, = 0.063 and = 0.065 with 266 reflections and = 0.055 and = 0.062 with 260 reflections, respectively, for which . In both structures, six ions lie at two distinguished three-fold axes of unit cell. Dehydrated -A sorbs 4 ethylene molecules per unit cell at (vapor pressure of ethylene is ca. 100 Torr). Each ion forms a lateral complex with an ethylene molecule. Four ions exist in a nearly tetrahedral environment, 2.210(7) apart from three framework oxygen ions (considering ethylene molecule as a monodentate ligand) and from each carbon atom of ethylene molecule.