1. Synthesis and Crystal Structure of AgBr Nanoclusters in the Sodalite Cavities of K + -Exchanged Zeolite A (LTA) Hyun Jung Kim, Seok Han Kim, Cheol Woong Kim, Ghyung Hwa Kim 1 and Nam Ho Heo * * Laboratory of Structural Chemistry, Department of Applied Chemistry Kyungpook National University, Daegu 702-701, Korea 1 Pohang Accelerator Laboratory, POSTECH, Pohang 790-784, Korea Introduction Various Properties of AgBr Nanoclusters in Zeolites A. Non-emissive indirect band gap materials (AgBr and Si) can become missive when formulated as small clusters. a-f B. The UV absorption band corresponding to the direct exciton absorption shifts the blue as size decrease. g,h C. The luminescence intensity arising from the direct recombination of exitons increases with decreasing size in AgBr. h D. The value of ionic conductivity of AgBr-montmorillonite higher than pure AgBr. i a W.Chen, G.McLendon, A.Marchetti, J.M.Rhem, M.I.Freedhoff, C.Myers, J.Am.Chem.Soc. 1994 116 1585-1586 b M.I.Comor, J.M.Nedeljkovic, Chemical Physics Letters 1999 299 233-236 c L.E.Brus, P.F.Szajowski, W.L.Wilson, T.D.Harris, S.Schuppler, P.H.Citrin, J.Am.Chem.Soc. 1995 117 2915-2922 d K.P.Johansson, A.P.Marchetti, G.McLendon, J.Phys.Chem. 1992 96 2873 e L.Brus, J.Phys.Chem. 1994 98 3575 f W.L.Wilson, P.F.Szajowski, L.E.Brus, Science 1993 262 1242 g H.Zhang, M.Mostafavi, J.Phys.Chem. B 1997 101 8443-8448 h M.I.Freedhoff, A.P.Marchetti, G.McLendon, Journal of Luminescence 1996 70 400-413 i A.Robledo, N.J.Garcia, J.C.Bazan, Solid State Ionics 2001 139 303-308 Ag-ANa-A 0.05 M AgNO 3 in CH 3 OH K-A (AgBr) Washing (CH 3 OH) 0.05 M KBr in CH 3 OH By flow method for 2 days Reaction with KBr in CH 3 OH for 2 days Preparation of K-A(0.5Ag 2 Br 2 )(KBr) Preparation of K-A(0.5Ag 2 Br 2 )(KBr) A. Preparation of Ag 12 -A & K-A(AgBr) B. X-ray diffraction experiment C. Structure determination of K-A(0.5Ag 2 Br 2 )(KBr) Experiments Table 1. Positional, Thermal, and Occupancy parameters of K 12 -A(0.5Ag 2 Br 2 ) (KBr) of K 12 -A(0.5Ag 2 Br 2 ) (KBr) 1116(201)2702(21) 8(g) K(1) 3269(947)5000 e 3123(147) 6(f) O(5) 2264(360)5000 e 1(b) K(4) 1952(276)3678(36) 8(g)Br(3) 1501(150)4269(29) 1268(38) 24(m) K(3) 271(83)4228(23) 2624(33) 24(m) O(4) 1030(102) 5000 e 2715(24) 12(j) Br(2 ’ ) 1689(123) 5000 e 3437(30)2143(33) 24(l)Br(2) 1315(110) 5000 e 2287(23) 12(j) Ag(2) 5247(414)5000 e 4174(54)648(56) 24(l) K(2) 1384(134)1142(25)0 12(i) Br(1) 1054(57)968(10) 8(g) Ag(1) 380(138) 2414(20) 8(g) K(1 ” ) 382(29)2592(12) 8(g) K(1 ’ ) 88(31)139(28) 846(58)490(28) 3442(7)1124(4) 24(m) O(3) 0084(38)382(31) 541(55)2948(5) 0 12(i) O(2) 000402(57)540(66)1167(100)5000 e -2247(9)0 12(h) O(1) 0031(10)176(16)212(16)207(16)3714(2)1829(2)0 24(k) (Si,Al) U 12 U 13 U 23 U 33 U 22 U 11 or U iso b zyx Wyckoff position Atoms 1.3(5)3 1.5(7)2 0.6(2)0.5 0.3(1)0.5 2.7(7)3 4.8(7)3 1.4(3)1 2.3(3)2 0.7(2)1 4.0(8)3 1.1(1)1 0.7(1)1 1.0(6)1 5.3(8)4 24 12 24 d variedfixed Occupancy c Results & Discussion X-ray diffraction experiment at 21  C Structure determination Structure determination Structure solution package : SHELX-97 Initial phasing with parameters of Na-A a Full-matrix least-squares refinement X-ray source : PLS (Beamline 4A MXW of Pohang Light Source) Mo K  radiation ( = 0.8265Å ) Space group of K-A(0.5Ag 2 Br 2 )(KBr) : Pm3m Cell parameter, a = 12.299(3) Å No. of reflections obsd. (Fo > 4  (Fo)) : 368 Final error indices R1 = 0.082, R2 = 0.227 A. Ag 2 Br 2 nanoclusters have been synthesized in a single crystal of Zeolite A B. Structure determination K 12 -A(0.5Ag 2 Br 2 )(KBr) : Pm3m, a = 12.299(3) Å R 1 = 0.082 for the 368 reflections with F o > 4  (F o ) C. Crystallographic characterization of Ag 2 Br 2 nanoclusters Ag–Br = 2.86(3) Å, Ag–Br–Ag = 92.2(15)º, Br-Ag-Br = 87.8(15)º D. Ag 2 Br 2 nanoclusters is stabilized by 10 strong interaction of Ag + with 6-ring oxygens. Ag(1)-O(3) = 3.06(2) Å E. Half of all sodalite units of K 12 -A(0.5Ag 2 Br 2 )(KBr) are filled with Ag 2 Br 2 nanoclusters. Conclusions Stereoview of a large cavity in K 12 -A(0.5Ag 2 Br 2 ) (KBr) Stereoview of a large cavity in K 12 -A(0.5Ag 2 Br 2 ) (KBr) Figure 2. A steroview of the large cavities (uc1 and uc2) in K-A(0.5Ag 2 Br 2 )(KBr). Ellipsoids of 20% probably are shown. Angles Distances 106.4(5) 110.6(4) 108.5(3) 112.2(5) 144.0(7) 158.8(7) 145.5(5) 88.4(11) 93.9(7) 103.0(11) 86.9(12) 92.2(15) 87.8(15) 102.7(16) O(1)-(Si,Al)-O(2) O(1)-(Si,Al)-O(3) O(2)-(Si,Al)-O(3) O(3)-(Si,Al)-O(3) (Si,Al)-O(1)-(Si,Al) (Si,Al)-O(2)-(Si,Al) (Si,Al)-O(3)-(Si,Al) O(3)-K(1)-O(3) O(3)-K(1’)-O(3) O(3)-K(1”)-O(3) O(3)-Ag(2)-O(3) Ag(1)-Br(1)-Ag(1) Br(1)-Ag(1)-Br(1) Br(2)-K(1)-Br(2’) 3.05(3) 3.47(8) 3.19(2) 2.83(3) 2.97(2) 3.22(3) 3.11(7) 2.76(3) 2.66(5) 2.85(5) 2.61(7) 3.10(6) 3.21(17) 2.61(16) 2.69(9) 3.14(5) 2.82(8) 3.22(4) 136.6(13) 111.8 111.6 175.4(18) 89.9(2) 170.2(19) 105.8(19) 103.1(18) 85.1(13) 73.9(16) 106.1(16) 180.0(15) 112.6(14) 85, 95 K(1)-Br(2)-K(1’) K(1)-Br(2)-K(2) K(1’)-Br(2)-K(2) K(1)-Br(2’)-K(1’) K(1)-Br(2’)-K(2) K(1)-Br(2’)-K(1”) K(1)-O(4)-K(2) K(1’)-O(4)-K(2) O(4)-K(1’)-Br(2’) K(1”)-Br(3)-K(3) K(3)-Br(3)-K(4) K(1”)-Br(3)-K(4) K(3)-Br(3)-K(3) O(4)-K(4)-O(4) Br(2)-K(1) Br(2)-K(2) Br(2)-K(1’) Br(2’)-K(1) Br(2’)-K(1’) Br(2’)-K(1”) Br(2’)-K(2) Br(2’)-K(3) K(1)-O(4) K(1’)-O(4) K(2)-O(4) K(3)-O(4) K(2)-O(5) K(3)-O(5) K(1”)-Br(3) K(3)-Br(3) K(4)-Br(3) K(4)-O(4) 1.664(4) 1.668(3) 1.665(3) 2.89(3) 2.76(2) 2.58(2) 3.06(2) 2.50(7) 3.05(4) 3.07(3) 2.78(5) 2.81(3) 2.79(3) 2.86(3) (Si,Al)-O(1) (Si,Al)-O(2) (Si,Al)-O(3) K(1)-O(3) K(1’)-O(3) K(1”)-O(3) Ag(1)-O(3) K(2)-O(1) K(2)-O(2) K(3)-O(1) K(3)-O(2) Ag(2)-O(1) Ag(2)-O(3) Ag(1)-Br(1) Table 2. Selected Interatomic Distances (Å) and Angles (deg) r (K + ) = 1.33 Å r (Ag + ) = 1.13 Å r (O 2- ) = 1.32 Å r (Br - ) = 1.96 Å Stereoview of a sodalite in K 12 -A(0.5Ag 2 Br 2 )(KBr) Stereoview of a sodalite in K 12 -A(0.5Ag 2 Br 2 )(KBr) Figure 1. A steoreview of a sodalite unit of K-A(0.5Ag 2 Br 2 )(KBr) showing absorbed Ag 2 Br 2 molecule. The Zeolite a framework is drawn with thick bonds between oxygens. Ellipsoids of 20% probably are shown. Deviation In from the (111) plane at O(3)s of 6-ring 1.72Å for K(1), 1.48Å for K(1’), 1.10Å for K(1”), -1.98Å for Ag(1)