No abstract

The crystal structures of hydrated (a = 12.32 A) and vacuum-dehydrated (a = 12.17 A) thallium-exchanged zeolite A have been determined by single crystal X-ray techniques. T1(I) ions are distributed among three equipoints in each structure: two such sites are on the threefold axis on either side of the six-oxygen ring and the third is near the center of the eight-oxygen ring. Small changes in cation positions and in the zeolite framework are observed upon dehydration. The shortest Tl(I)-0 approaches are 2.75 (2), 2.81 (2), and 2.86 (3) Á in the hydrated crystal and 2.64 (1), 2.60 (3), and 2.82 (3) A, respectively, for the dehydrated form. Changes in framework angles of +14, -17, and -6°at the three nonequivalent oxygen atoms, corresponding to rotations of aluminosilicate tetrahedra, are observed upon dehydration. powder photographic data, was supported by a grant from the Army Research Office (Durham). The computational work associated therewith was done in part at the MIT Computation Center.(2) V. Gramlich and W. M. Meier, Z. Kristallogr., 133, 134 (1971).(3) W. M. Meier, private communication (1964).(4) T. B. Reed and D. W.

No abstract

Die Komplexe (I) werden durch l :4‐molare Umsetzung von ThCl4‐8H3O, U(′I4, (NH4)4[Ce(SO4)4] oder Zr(NO3)4 mit dem Na‐Salz des Titelliganden in wäßriger Lösung gebildet und nach dem Umkristallisieren isoliert.

No abstract