Crystal structure of fully dehydrated fully Tl+-exchanged zeolite X

The structure of TI92-X (TI92Si100Al92O384), a = 25.043(4) Angstrom, fully dehydrated at 400 degrees C and 1 x 10(-6) torr, has been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd (3) over bar at 22(1)degrees C. The structure was refined to the final error indices R = 0.047 and R-w = 0.048 with 545 reflections for which I > 3 sigma(l). In this structure, 92 TI+ ions are located at four different crystallographic sites. Thirty-two fill site I' in the sodalite cavities on 3-fold axes opposite double 6-rings; each is 1.44 Angstrom from the plane of three oxygens (TI-O = 2.59(1) Angstrom, O-TI-O = 92.5(5)degrees). Another 32 TI+ ions fill site II opposite single 6-rings in the supercage; each is 1.56 A from the plane of three oxygens (TI-O = 2.68(1) Angstrom and O-TI-O = 89.7(1)degrees). About 16 TI+ ions are found at a III' site in the supercage (TI-O = 2.81(2) and 2.87(2) degrees), and the remaining 12 occupy another III' site (TI-O = 2.38(2) and 2.95(4) Angstrom). (C) Elsevier Science Inc. 1997.