• Korean Journal of Crystallography
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• v.6 no.2
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• pp.118-124
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• 1995

The crystal structure of an iodine sorption complex of vacumm-dehydrated Ag+ and Ca2+ exchanged zeolite A(a=12.174(3)Å) has been determined at 21℃ by single-crystal X-ray diffraction techniques in the cubic space group Pm3m. The crystal was prepared by flow method for three days using exchange solution in solution in which mole ratio of AgNO3 and Ca(NO3)2 was 1:150 with total concentration of 0.05 M. The complex was prepared by dehydration at 360℃ and 2×10-6 Torr for 2 days, followed by exposure to about 14.3 Torr of iodine vaporat 80℃ for 24 hours. Full-matrix least-squares refinement converged to the final error indices of R1=0.082, R2=0.068 using 122 reflections for which I > 3σ(I). Two Ag+ ions, 1.1 Ag+ ions, and 4.45 Ca2+ ions per unit cell are located on three different three-fold axes associated with 6-ring oxygens. Two Ag+ ions per unit cell are in the large cavity, 1.399(4)Å from the (111) plane of three oxygens. Another 1.1 Ag+ ions are found at opposite sites. Six iodine molecules are sorbed per unit cell. Each I2 molecule approaches a framework oxide ion axially (O-I=3.43(2)Å, I-I=2.92Å, I-I-O;166.1(3)°), by a charge transfer complex interaction. Two Ag+ ions make a close approach to the iodine molecules (Ag-I ; 2.73(2)Å).

• Korean Journal of Crystallography
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• v.8 no.2
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• pp.119-123
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• 1997

The complex [Ni(L)]I2 (1) (L:3,5,10,12-Tetramethly-1,4,8,11-tetraazacyclotetradecane) has been prepared and characterized by X-ray diffraction methods. The complex 1 crystallized in the orthorhombic system, space group Pcab with cell parameters a=13.293(1) Å, b=28.550(7) Å, c=10.804(1) Å, z=8. Least-squares refinement of 1 led to a R(Rw) factor of 0.043 (0.046) for 1851 observed reflections of Fo>3o (Fo). The crystal structure of 1 has a slightly distorted square-planar geometry and adopts the trans-III conformation.

• Korean Journal of Crystallography
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• v.9 no.1
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• pp.11-14
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• 1998

The synthesis and characterization of [Cu(L)](NCS)2 (1) (L:2,5,9,12-Tetramethyl-1,4,8,11-tetraazacyclotetradecane) are described. Crystal structure of 1 crystallizes in the monoclinic system, space group P21/a, a=7.622(2)Å, b=17.645(2) Å, c=8.223(3) Å, β=109.99(2)˚ Z=2. Least-squares refinement of 1 led to a R(Rw) factor of 0.087 (0.158) for 1535 observed reflections of F0>40(F0). The complex 1 has a square planar geometry with average Cu-N (secondary amines) bond distance of 2.030(4)Å. The axially disposed thiocyanate anions are not coordinated with Cu-N distances of 2.842(7) Å.

• Korean Journal of Crystallography
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• v.13 no.1
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• pp.17-20
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• 2002

The complex [Zn(L)₂(H₂O)₄] (1) (L = isonicotinate) has been prepared and characterized by X-ray crystallography. Compound 1 crystallizes in the triclinic space group P1, with a = 6.9062(4) , b = 9.2618(7) , c = 6.3313(3) , α = 104.986(6)°, β = 112.865(4)°, γ = 96.213(6)°, V = 350.41(4) , Z = 1, R₁(wR₂) for 1225 observed reflections of [I > 2σ(I)] was 0.0209 (0.0591). The coordination environment of the zinc atom can be described as an octahedron in which the isonicotinato ligands are mutually trans. Compound 1 is also connected into a two-dimensional chain via hydrogen-bonds.

• Journal of the Korean Chemical Society
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• v.37 no.2
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• pp.191-198
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• 1993

The crystal structures of $Cd_{6-}A$ evacuated at $2{\times}10^{-6}$ torr and $750^{\circ}C$ (a = 12.204(1) $\AA$) and dehydrated $Cd_{6-}A$ reacted with 0.1 torr of Cs vapor at $250^{\circ}C$ for 12 hours (a = 12.279(1) $\AA$) have been determined by single crystal X-ray diffraction techniques in the cubic space group Pm3m at $21(1)^{\circ}C.$ Their structures were refined to final error indices, $R_1=$ 0.081 and $R_2=$ 0.091 with 151 reflections and $R_1=$ 0.095 and $R_2=$ 0.089 with 82 reflections, respectively, for which I > $3\sigma(I).$ In vacuum dehydrated $Cd_{6-}A$, six $Cd^{2+}$ ions occupy threefold-axis positions near 6-ring, recessed 0.460(3) $\AA$ into the sodalite cavity from the (111) plane at O(3) : Cd-O(3) = 2.18(2) $\AA$ and O(3)-Cd-O(3) = $115.7(4)^{\circ}.$ Upon treating it with 0.1 torr of Cs vapor at $250^{\circ}C$, all 6 $Cd^{2+}$ ions in dehydrated $Cd_{6-}A$ are reduced by Cs vapor and Cs species are found at 4 crystallographic sites : 3.0 $Cs^+$ ions lie at the centers of the 8-rings at sites of $D_{4h}$ symmetry; ca. 9.0 Cs+ ions lie on the threefold axes of unit cell, ca. 7 in the large cavity and ca. 2 in the sodalite cavity; ca. 0.5 $Cs^+$ ion is found near a 4-ring. In this structure, ca. 12.5 Cs species are found per unit cell, more than the twelve $Cs^+$ ions needed to balance the anionic charge of zeolite framework, indicating that sorption of Cs0 has occurred. The occupancies observed are simply explained by two unit cell arrangements, $Cs_{12}-A$ and $Cs_{13}-A$. About 50% of unit cells may have two $Cs^+$ ions in sodalite unit near opposite 6-rings, six in the large cavity near 6-ring and one in the large cavity near a 4-ring. The remaining 50% of unit cells may have two Cs species in the sodalite unit which are closely associated with two out of 8 $Cs^+$ ions in the large cavity to form linear $(Cs_4)^{3+}$ clusters. These clusters lie on threefold axes and extend through the centers of sodalite units. In all unit cells, three $Cs^+$ ions fill equipoints of symmetry $D_{4h}$ at the centers of 8-rings.

• Journal of the Korean Chemical Society
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• v.35 no.3
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• pp.189-195
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• 1991

Two crystal structures of dehydrated $Ag_{2.8}ZN_{4.6}-A$ and of its ethylene sorption complex have been determined by single-crystal X-ray diffraction techniques. The structures were solved and refined in the cubic space group Pm3m at 23(1)$^{\circ}$C. Dehydration of two crystals studied were achieved at 400$^{\circ}$C and $2{\times}10^{-6}$ Torr for 2 days and one crystal was treated with 250 Torr of ethylene at 25(1)$^{\circ}$C. The structures of dehydrated $Ag_{2.8}ZN_{4.6}-A$ (a = 12.137(2) ${\AA}$ and of its ethylene sorption complex (a = 12.106(2)${\AA}$) were refined to final error indices, R(weighted) = 0.044 with 237 reflections and R(weighted) = 0.050 with 301 reflections, respectively, for which I > 3${sigma}$(I). 2.8 $Ag^+$ ions are recessed 0.922(2) ${\AA}$ from (111) plane of three 6-ring oxygens into the large cavity where each forms a lateral ${\pi}$ complex with an ethylene molecule. These $Ag^+$ ions are in 2.240(5)${\AA}$ from three framework oxide ions and 2.290(5) ${\AA}$ from each carbon atom of an ethylene molecule. The $Zn^{2+}$ ions occupy two different threefold axis positions of the unit cell. 2.8 $Zn^{2+}$ ions are recessed 0.408(2) ${\AA}$ from (111) plane of the 6-ring oxygens and each $Zn^{2+}$ ion forms a $\pi$ complex with an $C_2H_4$ molecule. The distances between $Zn^{2+}$ ions and carbon atom of ethylene molecule, Zn(2)-C = 2.78(4) ${\AA}$ are long. This indicates that this bond is relatively weak.

• Journal of the Korean Chemical Society
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• v.40 no.6
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• pp.427-435
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• 1996

The structures of fully dehydrated $Ca^{2+}$- and $Cs^+$-exchanged zeolite X, $Ca_{35}Cs_{22}Si_{100}Al_{92}O_{384}$($Ca_{35}Cs_{22}$-X; a=25.071(1) $\AA)$ and $Ca_{29}Cs_{34}Si_{100}Al_{92}O_{384}$($Ca_{29}Cs_{34}$-X; a=24.949(1) $\AA)$, have been determined by single-crystal X-ray diffraction methods in the cubic space group Fd3 at $21(1)^{\circ}C.$ Their structures were refined to the final error indices $R_1$=0.051 and $R_2$=0.044 with 322 reflections for $Ca_{35}Cs_{22}$-X, and $R_1$=0.058 and $R_2$=0.055 with 260 reflections for $Ca_{29}Cs_{34}$-X; $I>3\sigma(I).$ In both structures, $Ca^{2+}$ and $Cs^+$ ions are located at five different crystallographic sites. In dehydrated $Ca_{35}Cs_{22}$-X, sixteen $Ca^{2+}$ ions fill site I, at the centers of the double 6-rings(Ca-O=2.41(1) $\AA$ and $O-Ca-O=93.4(3)^{\circ}).$ Another nineteen $Ca^{2+}$ ions occupy site II (Ca-O=2.29(1) $\AA$, O-Ca-O=118.7(4)') and ten $Cs^+$ ions occupy site II opposite single six-rings in the supercage; each is $1.95\AA$ from the plane of three oxygens (Cs-O=2.99(1) and $O-Cs-O=82.3(3)^{\circ}).$ About three $Cs^+$ ions are found at site II', 2.27 $\AA$ into sodalite cavity from their three-oxygen plane (Cs-O=3.23(1) $\AA$ and $O-Cs-O=75.2(3)^{\circ}).$ The remaining nine $Cs^+$ ions are statistically distributed over site Ⅲ, a 48-fold equipoint in the supercages on twofold axes (Cs-O=3.25(1) $\AA$ and Cs-O=3.49(1) $\AA).$ In dehydrated $Ca_{29}Cs_{34}$-X, sixteen $Ca^{2+}$ ions fill site I(Ca-O=2.38(1) $\AA$ and $O-Ca-O=94.1(4)^{\circ})$ and thirteen $Ca^{2+}$ ions occupy site II (Ca-O=2.32(2) $\AA$, $O-Ca-O=119.7(6)^{\circ}).$ Another twelve $Cs^+$ ions occupy site II; each is $1.93\AA$ from the plane of three oxygens (Cs-O=3.02(1) and $O-Cs-O=83.1(4)^{\circ})$ and seven $Cs^+$ ions occupy site II'; each is $2.22\AA$ into sodalite cavity from their three-oxygen plane (Cs-O=3.21(2) and $O-Cs-O=77.2(4)^{\circ}).$ The remaining sixteen $Cs^+$ ions are found at III site in the supercage (Cs-O=3.11(1) $\AA$ and Cs-O=3.46(2) $\AA).$ It appears that $Ca^{2+}$ ions prefer sites I and II in that order, and that $Cs^+$ ions occupy the remaining sites, except that they are too large to be stable at site I.

• Korean Journal of Crystallography
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• v.4 no.1
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• pp.1-5
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• 1993

The crystal structure of N-(2'-chloro-4'-vitrophenyl)-5-chlorosalicylamide( Niclosamide ) monohydrate has been determined from 1976 sig- nificant independent reflections collected on an automated CAD4 diffractometer using graphitemonochromated Mo-Ka radiation. The crystal is monoclinic, space group P211c, with unit cell dimensions, a=11.331 (3), b=16.964(2), c=7.347(4)A , P =98.20(3)° and Z=4 at T=293k. The structure was solved by direct method using seminvariants of ggg Parity group and refined by the full-matrix least-square method, resulting model with reliability factor, R=0.046. The feature of the molecule show planar structure in parallel to the ab crystal plane.

• Korean Journal of Crystallography
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• v.13 no.3_4
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• pp.148-151
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• 2002

The molecular and crystal structure of metalaxyl C/sub15/H/sub21/NO₄, was determined by single crystal x-ray diffraction study. Crystallographic data for, title compound P2₁/c, a=7.849(4) Å, b=13.081(5) Å, c=15.100(3) Å, β=101.8(2)°, V= 1517.6(3) ų, Z=4. The molecular. Structure model was solved by direct method and refined by full-matrix least- squares. The final reliable factor, R, is 0.067 for 1694 independent reflections (F/sub o//sup 2/>4σ(F/sub o//sup 2/)). The molecular structure of title compound shows an intramolecular hydrogen bond: Cl2-Hl2A…O1.

• Korean Journal of Crystallography
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• v.13 no.3_4
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• pp.152-157
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• 2002

The molecular and crystal structure of Tricyclazole, C/sub9/H/sub7/N₃S, has been determined by single crystal x-ray diffraction study. Crystallographic data for title compound: Pca2₁, a=14.889(1) Å, b=7.444(1) Å, c=15.189(2) Å, V=1683.3(3) ų, Z= 8. The molecular structure model was solved by direct methods and refined by full-matrix least-squares. The final reliable factor, R, is 0.047 for 1533 independent reflections (F/sub o//sup 2/)). The asymmetry unit contains two molecules which are in plate conformation, parallel to each other and related by a pseudo four-fold screw on the b-direction.