Crystal Structure of a Cadmium Sorption Complex of Dehydrated Fully Cd2+-Exchanged Zeolite X Containing Cd2+, Cd+, and Cd0

• DOI: 10.1021/jp014724o
• Publication Date: 2002-09-17T20:25:27Z
• Authors: Eun Young Choi; Seok Hee Lee; Yang Kim; Young Wook Han; Karl Seff
• Keywords: Sodalite

A single crystal of fully dehydrated Cd2+-exchanged zeolite X, Cd46Si100Al92O384 per unit cell, was exposed at 320 °C to 0.005 Torr Cd vapor for 9 days. The resultant crystal, Cd68Si100Al92O384 cell [a = 24.953(6) Å], determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3̄m 21(1) °C. structure refined final error indices R1 0.073 and R2 0.100 with 249 reflections which I > 3σ(I). In this structure, species (formally Cd2+, Cd+, Cd0) are found seven crystallographic sites. Twenty-eight Cd2+ ions three sites: eight occupy site I' sodalite associate four Cd0 atoms near II' form (Cd3)4+ clusters [Cd2+−Cd0−Cd2+ 105.2(7)°, Cd2+−Cd0 2.76(5) Å, Cd2+−O 2.176(25) Cd0−O 3.03(5) Å] cavities cell. remaining 20 sites II occupancies six 14 [trigonal, Cd−O ca. 2.19(2) Å both]. Thirty-six Cd+ I, centers double six-oxygen rings [octahedral, 2.559(14) Å]; 18 lie I', cavity opposite 2.393(25) 12 supercage 2.418(23) Å]. Of 46 cations initially present have reacted 36 monatomic give cations. Highly reducing cadmium highly dispersed within zeolite.