 To whom correspondence should be addressed. Fax: #386-1-4259- 244. E-mail: natasa.zabukovec@ki.si. Journal of Solid State Chemistry 156, 480 } 486 (2001) doi:10.1006/jssc.2000.9027, available online at http://www.idealibrary.com on Syntheses and Structures of Two Ammonium Zinc Gallophosphates: Analcime and Paracelsian analogs Natas \ a Zabukovec Logar, Maja Mrak, and Venc \ eslav Kauc \ ic \ National Institute of Chemistry, P.O. Box 3430, SI-1001 Ljubljana, Slovenia and Amalija Golobic \ Faculty for Chemistry and Chemical Technology, University of Ljubljana, As \ kerc \ eva 5, SI-1000 Ljubljana, Slovenia Received August 1, 2000; in revised form October 24, 2000; accepted November 6, 2000; published online December 21, 2000 Two ammonium zinc gallophosphates (I) (NH 4 ) 16 [Zn 16 Ga 8 P 24 O 96 ] and (II) (NH 4 ) 4 [Zn 4 Ga 4 P 8 O 32 ] were hy- drothermally synthesized and characterized using single crystal X-ray di4raction. The (I) (NH 4 ) 16 [Zn 16 Ga 8 P 24 O 96 ] crystallizes in a cubic I 2 1 3 space group (a  13.456(1) A s , V  2436.5(5) A s 3 , R (on F )  2.47%, R w (on F )  2.48%). It has a zeolite analcime topology with distorted eight-member ring channels. Zn and Ga atoms share the same crystallographic site with a partial occupancy of Zn/Ga  0.67/0.33. Ammonium ions lie on the three-fold crystallographic axes and compensate for a negatively charged framework. The second compound (II) (NH 4 ) 4 [Zn 4 Ga 4 P 8 O 32 ] has a monoclinic symmetry (P2 1 /a, a  9.406(1) A s , b  9.881(1) A s , c  8.612(1) A s ,   90.58(1)3, R (on F )  2.7%, R w (on F )  3.0%). It is isostructural with a feldspar paracelsian. Zinc and gallium occupy two crystallo- graphic sites with a partial occupancy of Zn(1)/Ga(1)  0.53(6)/0.47(6) and Zn(2)/Ga(2)  0.47(6)/0.53(6). Am- monium ions lie in the elliptical eight-member ring openings of the three-dimensional framework.  2001 Academic Press Key Words: gallophosphates; open-frameworks; microporous materials; ZnGaPO; GaPO+ANA; analcime; paracelsian; structure determination. INTRODUCTION Open framework aluminophosphates and gallophos- phates have been studied intensively in the past years (1). Many have framework topologies analogous to aluminosili- cates zeolites, while others have unique structures (2). The introduction of divalent metal cations like Co, Mn, Zn, etc., on the Al or Ga framework sites results in negatively charged frameworks, which can be useful for catalytic, absorption or ion-exchange applications. Exam- ples of microporous metal gallophosphates found in the literature are Co-, Zn-, Fe-, or Mn-substituted gallophos- phate phases analoguos to zeolites gismondine (3, 4), laumontite (5), sodalite (6), thomsonite (6), and new topolo- gies (CGS (7), CGF (8), SBS (9), and SBT (9) structure types (2)). In most of them the Me/Ga ratios (Me"Co, Zn, Mn, and Fe) are one or even more. A review of some of the above structures has recently been published by Chippindale and Cowley (10). Here we report on the synthesis and structure determination by single-crystal X-ray di!raction of two synthetic zinc gallophosphates, one with a zeolite analcime topology and an accompanying phase, which is isostructur- al with a feldspar mineral paracelsian. Analcime is a well-known natural zeolite, Na  [Al  Si  O  ] ) 16H  O, with distorted eight-member ring channels (4.21.6 A s ) (2). The minerals leucite and pollucite are iso- structural with analcime, but have di!erent chemical com- positions (K and Cs instead of Na extraframework cations). Some nonsilica forms of analcime structure type are known as well, namely aluminophosphates AlPO  -24, AlPO  -pollucite (2), cobalt aluminophosphate Cs  [Al  Co  P  O  ] (2, 6), two gallogermanates (NH  )  [Ga  Ge  O  ] and Cs  [Ga  Ge  O  ] (11), and a family of metal germanate phases A  MGe  O  : A"Rb, Cs; M"Be, Mg, Co, Zn (12). Most of the synthetic forms of analcime analogs were hydrothermally synthesized at tem- peratures around 2003C. The ideal topological symmetry of analcime structure type is cubic with a space group Ia}3d; however, in many natural and synthetic samples the symmetry is lowered. There are some natural analcime samples with tetragonal and orthorhombic symmetry (13). In the synthetic phosphorous-substituted analcime Na  [Al  Si  P  O  ] ) 480 0022-4596/01 $35.00 Copyright  2001 by Academic Press All rights of reproduction in any form reserved.