Cupramine Ion-Exchanged Nax Zeolite and Crystal-Structure Analysis
(EN)
Vlessidis, A. G.
(EN)
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας
(EL)
Vlessidis, A. G.
(EN)
The Cuprammine exchanged NaX zeolite (M = 17846, cubic, space group Fa3mBAR, a = 24,915(1) angstrom, V = 15466 angstrom3) is investigated for site occupancy by the cuprammonium ions. Intensity data are resolved into component hkl contributions by treating the known framework sites as conventional heavy atoms. Difference Fourier and least square methods were used to reveal and refine the intersticial Cu, Na, NH3 and water in hydrated samples. Final R = 0,09 for 75 F and sigma-criterion for the refinement F > 3sigma(F) were used. It is found that 25% of the cuprammine species are located in I'(U) site [xxx with x = 0,100(2)], origin at centre (3mBAR) which is close to the centre of the sodalite cage while the rest is labile in the supercages.
(EN)
