Samples of two differently prepared zeolite rho loaded with different amounts of dimethylamine (DMA) were studied in their hydrated forms by X-ray diffraction. Both zeolites are partially dealuminated, as indicated by nonframework A1 which is assumed to be A1203 or A1OOH. Series I was prepared from dry-calcined NHn-rho at 873 K, series II from steam-calcined NHn-rho at 773 K. The samples were loaded with different amounts of DMA. Rietveld refinements yielded the following results for series I: (1) H3.8(H-DMA)sCs0.2AI9Si39096.A1203.21H20, X-ray data collection at room temperature, Im3m, a = 15.0590 (2) /~, Rwp = 0.089; (2) (H-DMA)s.sCso.2Al9 Si39096.A1203.18H20, X-ray data collection at room temperature, Im3m, a = 15.0680(2)A,, Rwp = 0.091. Series II: (3) H0.3(H-DMA)sCs0.TA16Sia2096.2.5AleO3.24HeO, X-ray data collection at room temperature, Im3m, a = 15.0596 (2) A,, Rwp = 0.120. DMA resides on the center axis through the c~-cage with the N atoms pointing to the single eight-ring and the two methyl groups oriented towards the center of the c~-cage.

Samples of two differently prepared zeolite rho loaded with different amounts of monomethylamine (MMA) were studied in their hydrated and dehydrated forms by X-ray and neutron diffraction. Both zeolites are partially dealuminated, as indicated by nonframework alumina, which is assumed to be A1203 or A1OOH. Series I was prepared from dry-calcined NHa-rho at 873K, series II from steam-calcined NHn-rho at 773K. The samples were loaded with different amounts of deuterated MMA, Rietveld refinements yielded the following results for series I (dry): (4), anhydrous and deuterated, neutron data collected at 5 K, disproportionation into two phases in 12~3m with a = 14.9151 (2) and 14.6475 (8)/~, Rwp = 0.031. In the hydrated samples MMA resides on the center axis in the c~-cage with the N atoms pointing to the single eight-ring; upon dehydration it migrates into the double eight-rings.