A novel microporous Ge-material containing nine-rings

(NH4)(2)Ge7O15 is the first microporous material containing nine-rings cons tituted by tetrahedral and octahedral germanium species. Its channel struct ure is characterized by a nine-ring channel running along the [001] directi on. These channels are lined forming cages which are capped by six-rings gi ving rise to smaller tunnels in [110] [010] directions. Two, related by inv ersion center, NH4+ cations are housed in each cage bonded to several oxyge n atoms of the framework through hydrogen bonds. The paper reports the full structural data as well as thermal stability conditions and the first cata lytic essays. (C) 1999 Elsevier Science Ltd. All rights reserved.