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Framework Structure (framework + structure)
Kinds of Framework Structure Selected AbstractsChemInform Abstract: New Scandium Rhodium Boride Sc4Rh17B12 with a Framework Structure: Synthesis, Crystal Structure, and Properties.CHEMINFORM, Issue 21 2009A. M. Alekseeva Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] [Me4N][Cu2(NCS)3] , A Compound Having a Framework Structure with Large Channels.CHEMINFORM, Issue 51 2005R. Dilshad Abstract For Abstract see ChemInform Abstract in Full Text. [source] Two Different Three-Dimensional Microporous Framework Structures in [Mn2(H2O)4{W (CN)8}×4H2O]n and [Mn2(H2O)4{W(CN)8} (OH)×2H2O]n.CHEMINFORM, Issue 16 2004Wen Dong Abstract For Abstract see ChemInform Abstract in Full Text. [source] The Prediction of Inorganic Crystal Framework Structures Using Excluded Regions within a Genetic Algorithm Approach.CHEMINFORM, Issue 12 2004Scott M. Woodley No abstract is available for this article. [source] Direct Synthesis of Highly Stable Mesoporous Molecular Sieves Containing Zeolite Building Units,ADVANCED FUNCTIONAL MATERIALS, Issue 2 2005A. Sakthivel Abstract A novel, one-step synthesis of a highly stable mesoporous molecular sieve (MMS-H), which has a structure analogous to MCM-48 but which contains zeolite building units, is reported. A variety of experimental techniques,X-ray diffraction (XRD), N2 adsorption/desorption, transmission electron microscopy (TEM), Fourier-transform infrared (FTIR) spectroscopy, hyperpolarized 129Xe,NMR, and solid-state 27Al and 31P,magic-angle spinning (MAS) NMR spectroscopies,have been used to characterize the framework structure, porosity, and acidity of this novel mesoporous/microporous composite material, which is also found to possess superior thermal, hydrothermal, steam, and mechanical stabilities. [source] Chlorartinite, a volcanic exhalation product also found in industrial magnesia screedJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 5 2006Kunihisa Sugimoto The volcanic exhalation product chlorartinite, [Mg2(CO3)(H2O)(OH)]Cl·H2O, has recently been found to be a minor, and in some samples a major, component of magnesia floors for industrial use. In order to be able to perform quantitative phase analysis using the Rietveld method, its crystal structure was determined from high-resolution synchrotron powder diffraction data by the global optimization technique of simulated annealing and Rietveld refinement. The final Rp and Rwp values are 5.23% and 6.56%, respectively. Chlorartinite crystallizes in the rhombohedral space group R3c (No. 161), with a = 23.14422,(16),Å, c = 7.22333,(5),Å, V = 3350.84,(5),Å3, Z = 18. The building units of chlorartinite consist of MgO6 octahedra forming 15-membered puckered rings which are interconnected by CO3 triangular moieties. The rings are stacked to form a honeycomb-like three-dimensional framework structure with large isolated channels. Within the channels, free chlorine atoms and disordered water molecules are located. [source] The Effects of Temperature on the Local Structure of Metakaolin-Based Geopolymer Binder: A Neutron Pair Distribution Function InvestigationJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 10 2010Claire E. White Neutron pair distribution function (PDF) analysis is utilized to advance the understanding of the local atomic structural characteristics of geopolymer binders derived from metakaolin, specifically the nature and amount of the water associated with these materials. Samples were heated in air to temperatures up to 1200°C, then analyzed ex situ by high momentum transfer neutron total scattering and PDF analysis. Water contained in large pores, along with water associated with hydration of potassium cations in the geopolymer framework structure, comprise the majority of water in this material. The remaining water is situated in small pores and as terminal hydroxyl groups attached to the Si,Al framework. The Si,Al framework structure undergoes only subtle rearrangement upon heating, but maintains a tetrahedral aluminosilicate framework environment. After crystallization with heating beyond 1000°C, the geopolymer gel is predominantly converted to leucite, with small amounts of amorphous mullite and glassy silica, which have never before been observed in heated geopolymers. This demonstrates the value of neutron PDF analysis to probe the local structure of these important geopolymeric materials. [source] Three isomeric 1-(2-chloronicotinoyl)-2-(nitrophenyl)hydrazines, including three polymorphs of 1-(2-chloronicotinoyl)-2-(2-nitrophenyl)hydrazine: hydrogen-bonded supramolecular structures in two and three dimensionsACTA CRYSTALLOGRAPHICA SECTION B, Issue 1 2007Solange M. S. V. Wardell 1-(2-Chloronicotinoyl)-2-(2-nitrophenyl)hydrazine, C12H9ClN4O3, crystallizes in three polymorphic forms, two monoclinic forms in space groups Cc (Ia) and P21 (Ib), and an orthorhombic form in space group Pbcn (Ic). In the Cc polymorph (Ia) the molecules are linked into sheets by combinations of one N,H,O and two C,H,O hydrogen bonds, while in the P21 polymorph (Ib) the molecules are linked into sheets by combinations of three hydrogen bonds, one each of N,H,O, C,H,N and C,H,O types. In the orthorhombic polymorph (Ic) the molecules are linked into a complex three-dimensional framework structure by a combination of one N,H,O, one N,H,N and three C,H,O hydrogen bonds, and an aromatic ,,, stacking interaction. In the isomeric compound 1-(2-chloronicotinoyl)-2-(3-nitrophenyl)hydrazine (II) the molecules are again linked into a three-dimensional framework, this time by a combination of three hydrogen bonds, one each of N,H,O, N,H,N and C,H,O types, weakly augmented by a ,,, stacking interaction. The molecules of 1-(2-chloronicotinoyl)-2-(4-nitrophenyl)hydrazine (III) are linked into sheets by a combination of three hydrogen bonds, one each of N,H,O, N,H,N and C,H,O types. [source] Two similarly substituted benzo[h]pyrazolo[3,4- b]quinoline-5,6(10H)-diones: supramolecular structures in two and three dimensionsACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2010Yurina Díaz The molecules of 8-methyl-7,10-diphenyl-5H -benzo[h]pyrazolo[3,4- b]quinoline-5,6(10H)-dione, C27H17N3O2, (I), are weakly linked into chains by a single C,H...O hydrogen bond, and these chains are linked into sheets by a ,,, stacking interaction involving pyridyl and aryl rings. In 8-methyl-7-(4-methylphenyl)-10-phenyl-5H -benzo[h]pyrazolo[3,4- b]quinoline-5,6(10H)-dione, C28H19N3O2, (II), the molecules are linked into a three-dimensional framework structure by a combination of C,H...N, C,H...O and C,H...,(arene) hydrogen bonds, together with a ,,, stacking interaction analogous to that in (I). [source] Poly[[tetraaqua(,7 -pyridine-2,3,5,6-tetracarboxylato)dicadmium(II)] monohydrate]ACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010Sitang Yan The title compound, {[Cd2(C9HNO8)(H2O)4]·H2O}n, consists of two crystallographically independent CdII cations, one tetrabasic pyridine-2,3,5,6-tetracarboxylate (pdtc) anion, four coordinated water molecules and one solvent water molecule. The CdII cations have distorted square-antiprismatic (one pyridine N, six carboxylate O and one water O atom) and octahedral (three carboxylate O and three water O atoms) coordination environments. Each pdtc ligand employs its pyridine and carboxylate groups to chelate and bridge seven CdII cations. The square-antiprismatic coordinated CdII cations are linked by pdtc ligands into a lamellar framework structure, while the octahedral coordinated CdII cations are bridged by the ,2 -carboxylate O atoms and the pdtc ligands into a chain network that further joins neighbouring lamellae into a three-dimensional porous network. The cavities are filled with solvent water molecules that are linked to the host through complex hydrogen bonding. [source] A three-dimensional hydrogen-bonded framework in (2S*,4R*)-7-fluoro-2- exo -[(E)-styryl]-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepineACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010Lina M. Acosta Molecules of the title compound, C18H16FNO, are linked into a three-dimensional framework structure by a combination of two C,H...O hydrogen bonds and three C,H...,(arene) hydrogen bonds. Comparisons are made with the (2R,4R) diastereoisomer and with the corresponding pair of diastereoisomeric 7-chloro analogues. [source] (E)- N -{[6-Chloro-4-(4-chlorophenyl)-3-methyl-1-phenyl-1H -pyrazolo[3,4- b]pyridin-5-yl]methylene}benzene-1,2-diamine: a three-dimensional framework structure built from only two hydrogen bondsACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2010Yurina Díaz The molecules of the title compound, C26H19Cl2N5, are conformationally chiral, with none of the aryl groups coplanar with the pyrazolo[3,4- b]pyridine core of the molecule. A single unique N,H...N hydrogen bond links the molecules into two symmetry-related sets of C(11) chains running parallel to the [011] and [01] directions, respectively, and these two sets of chains are linked into a continuous three-dimensional framework structure by a single unique C,H...N hydrogen bond which forms a chain parallel to the [100] direction. [source] Poly[[aqua(4,4,-diazenediyldibenzoato-,4O,O,:O,,,O,,,)cadmium(II)]: a twofold interpenetrated three-dimensional coordination polymer of PtS topologyACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2009Ru-Guo Wang In the title coordination compound, [Cd(C14H8N2O4)(H2O)]n, the CdII cation and the coordinated water molecule lie on a twofold axis, whereas the ligand lies on an inversion center. The CdII center is five-coordinated in a distorted square-pyramidal geometry by four carboxylate O atoms from four different 4,4,-diazenediyldibenzoate (ddb) anions and one water O atom. The three-dimensional frameworks thus formed by the bridging ddb anions interpenetrate to generate a three-dimensional PtS-type network. Additionally, the coordination water molecule and the carboxylate O atom form a hydrogen-bonding interaction, stabilizing the three-dimensional framework structure. [source] Proton transfer versus nontransfer in compounds of the diazo-dye precursor 4-(phenyldiazenyl)aniline (aniline yellow) with strong organic acids: the 5-sulfosalicylate and the dichroic benzenesulfonate salts, and the 1:2 adduct with 3,5-dinitrobenzoic acidACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2009Graham Smith The structures of two 1:1 proton-transfer red,black dye compounds formed by reaction of aniline yellow [4-(phenyldiazenyl)aniline] with 5-sulfosalicylic acid and benzenesulfonic acid, and a 1:2 nontransfer adduct compound with 3,5-dinitrobenzoic acid have been determined at either 130 or 200,K. The compounds are 2-(4-aminophenyl)-1-phenylhydrazin-1-ium 3-carboxy-4-hydroxybenzenesulfonate methanol solvate, C12H12N3+·C7H5O6S,·CH3OH, (I), 2-(4-aminophenyl)-1-phenylhydrazin-1-ium 4-(phenyldiazenyl)anilinium bis(benzenesulfonate), 2C12H12N3+·2C6H5O3S,, (II), and 4-(phenyldiazenyl)aniline,3,5-dinitrobenzoic acid (1/2), C12H11N3·2C7H4N2O6, (III). In compound (I), the diazenyl rather than the aniline group of aniline yellow is protonated, and this group subsequently takes part in a primary hydrogen-bonding interaction with a sulfonate O-atom acceptor, producing overall a three-dimensional framework structure. A feature of the hydrogen bonding in (I) is a peripheral edge-on cation,anion association also involving aromatic C,H...O hydrogen bonds, giving a conjoint R12(6)R12(7)R21(4) motif. In the dichroic crystals of (II), one of the two aniline yellow species in the asymmetric unit is diazenyl-group protonated, while in the other the aniline group is protonated. Both of these groups form hydrogen bonds with sulfonate O-atom acceptors and these, together with other associations, give a one-dimensional chain structure. In compound (III), rather than proton transfer, there is preferential formation of a classic R22(8) cyclic head-to-head hydrogen-bonded carboxylic acid homodimer between the two 3,5-dinitrobenzoic acid molecules, which, in association with the aniline yellow molecule that is disordered across a crystallographic inversion centre, results in an overall two-dimensional ribbon structure. This work has shown the correlation between structure and observed colour in crystalline aniline yellow compounds, illustrated graphically in the dichroic benzenesulfonate compound. [source] Four differently substituted 2-aryl-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepines: hydrogen-bonded structures in one, two and three dimensionsACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2009Sandra L. Gómez In (2RS,4SR)-7-chloro-2- exo -(2-chloro-6-fluorophenyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C16H12Cl2FNO, (I), molecules are linked into chains by a single C,H...,(arene) hydrogen bond. (2RS,4SR)-2- exo -(2-Chloro-6-fluorophenyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C16H13ClFNO, (II), is isomorphous with compound (I) but not strictly isostructural with it, as the hydrogen-bonded chains in (II) are linked into sheets by an aromatic ,,, stacking interaction. The molecules of (2RS,4SR)-7-methyl-2- exo -(4-methylphenyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C18H19NO, (III), are linked into sheets by a combination of C,H...N and C,H...,(arene) hydrogen bonds. (2S,4R)-2- exo -(2-Chlorophenyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C16H14ClNO, (IV), crystallizes as a single enantiomer and the molecules are linked into a three-dimensional framework structure by a combination of one C,H...O hydrogen bond and three C,H...,(arene) hydrogen bonds. [source] A new three-dimensional cobalt(II) coordination polymer with a 4-connected CdSO4 -like topologyACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2009Zhan-Lin Xu The title cobalt(II) coordination polymer, poly[[diaquacobalt(II)]-,4 -3,3,-(p -phenylene)diacrylato], [Co(C12H8O4)(H2O)2]n, was obtained by reaction of Co(NO3)2·6H2O and 3,3,-(p -phenylene)diacrylic acid (H2L) under hydrothermal conditions. Each CoII cation sits on a centre of inversion and is hexacoordinated by six O-atom donors in an octahedral geometry. The CoII centres are connected by four centrosymmetric L2, anions, resulting in a three-dimensional framework structure. The coordinated water molecules and carboxylate O atoms form hydrogen-bond interactions, stabilizing the structure of the three-dimensional framework. Topologically, the framework represents a rare example of the three-dimensional 4-connected CdSO4 network type. The metal cations and the organic ligand both show in-plane coordination with respect to the extended structure. [source] Three-dimensional framework structures: isomorphous bis(2,6-diamino-3,5-dibromopyridinium) tetrabromidometallate(II) salts with CdII and MnIIACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2009Rawhi H. Al-Far In the structural motifs of two isomorphous triclinic salts, (C5H6Br2N3)2[MBr4] (M = CdII and MnII), each [MBr4]2, anion interacts with eight surrounding 2,6-diamino-3,5-dibromopyridinium cations through intermolecular C/N,H...Br and Br...Br interactions, leading to a three-dimensional framework structure. The cations show a minor degree of ,,, stacking, adding extra stability to the three-dimensional architecture. [source] 2-Methoxy-3-methyl-6-oxo-4-(2,3,4-tri- O -acetyl-,- d -xylopyranosylamino)-1,6-dihydropyrimidine-5-carbaldehyde 0.065-hydrate and 2-methylsulfanyl-6-oxo-4-(2,3,4-tri- O -acetyl-,- d -xylopyranosylamino)-1,6-dihydropyrimidine-5-carbaldehyde: hydrogen-bonded structures in one or three dimensionsACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2009Justo Cobo The organic components of 2-methoxy-3-methyl-6-oxo-4-(2,3,4-tri- O -acetyl-,- d -xylopyranosylamino)-1,6-dihydropyrimidine-5-carbaldehyde 0.065-hydrate, C18H23N3O10·0.065H2O, (I), which crystallizes with Z, = 2 in the space group P212121, are linked into a three-dimensional framework structure by a combination of four C,H...O hydrogen bonds. In 2-methylsulfanyl-6-oxo-4-(2,3,4-tri- O -acetyl-,- d -xylopyranosylamino)-1,6-dihydropyrimidine-5-carbaldehyde, C17H21N3O9S, (II), where the pyrimidine fragment is disordered with two different conformations for the methylsulfanyl substituent, molecules are linked into chains of rings by a combination of N,H...O and C,H...O hydrogen bonds. [source] Poly[diaqua(,-4,4,-bipyridine-,2N:N,)bis(,-cyanido-,2C:N)bis(cyanido-,C)nickel(II)copper(II)]: a metal,organic cyanide-bridged frameworkACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2008Olha Sereda The structure of the title compound, [NiCu(CN)4(C10H8N2)(H2O)2]n or [{Cu(H2O)2}(,-C10H8N2)(,-CN)2{Ni(CN)2}]n, was shown to be a metal,organic cyanide-bridged framework, composed essentially of ,Cu,4,4,-bpy,Cu,4,4,-bpy,Cu, chains (4,4,-bpy is 4,4,-bipyridine) linked by [Ni(CN)4]2, anions. Both metal atoms sit on special positions; the CuII atom occupies an inversion center, while the NiII atom of the cyanometallate sits on a twofold axis. The 4,4,-bpy ligand is also situated about a center of symmetry, located at the center of the bridging C,C bond. The scientific impact of this structure lies in the unique manner in which the framework is built up. The arrangement of the ,Cu,4,4,-bpy,Cu,4,4,-bpy,Cu, chains, which are mutually perpendicular and non-intersecting, creates large channels running parallel to the c axis. Within these channels, the [Ni(CN)4]2, anions coordinate to successive CuII atoms, forming zigzag ,Cu,N[triple-bond]C,Ni,C[triple-bond]N,Cu, chains. In this manner, a three-dimensional framework structure is constructed. To the authors' knowledge, this arrangement has not been observed in any of the many copper(II),4,4,-bipyridine framework complexes synthesized to date. The coordination environment of the CuII atom is completed by two water molecules. The framework is further strengthened by O,H...N hydrogen bonds involving the water molecules and the symmetry-equivalent nonbridging cyanide N atoms. [source] Cationic, neutral and anionic metal(II) complexes derived from 4-oxo-4H -pyran-2,6-dicarboxylic acid (chelidonic acid)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2007Vaduganathan Yasodha The structures of five metal complexes containing the 4-oxo-4H -pyran-2,6-dicarboxylate dianion illustrate the remarkable coordinating versatility of this ligand and the great structural diversity of its complexes. In tetraaquaberyllium 4-oxo-4H -pyran-2,6-dicarboxylate, [Be(H2O)4](C7H2O6), (I), the ions are linked by eight independent O,H...O hydrogen bonds to form a three-dimensional hydrogen-bonded framework structure. Each of the ions in hydrazinium(2+) diaqua(4-oxo-4H -pyran-2,6-dicarboxylato)calcate, (N2H6)[Ca(C7H2O6)2(H2O)2], (II), lies on a twofold rotation axis in the space group P2/c; the anions form hydrogen-bonded sheets which are linked into a three-dimensional framework by the cations. In bis(,-4-oxo-4H -pyran-2,6-dicarboxylato)bis[tetraaquamanganese(II)] tetrahydrate, [Mn2(C7H2O6)2(H2O)8]·4H2O, (III), the metal ions and the organic ligands form a cyclic centrosymmetric Mn2(C7H2O6)2 unit, and these units are linked into a complex three-dimensional framework structure containing 12 independent O,H...O hydrogen bonds. There are two independent CuII ions in tetraaqua(4-oxo-4H -pyran-2,6-dicarboxylato)copper(II), [Cu(C7H2O6)(H2O)4], (IV), and both lie on centres of inversion in the space group P; the metal ions and the organic ligands form a one-dimensional coordination polymer, and the polymer chains are linked into a three-dimensional framework containing eight independent O,H...O hydrogen bonds. Diaqua(4-oxo-4H -pyran-2,6-dicarboxylato)cadmium monohydrate, [Cd(C7H2O6)(H2O)2]·H2O, (V), forms a three-dimensional coordination polymer in which the organic ligand is coordinated to four different Cd sites, and this polymer is interwoven with a complex three-dimensional framework built from O,H...O hydrogen bonds. [source] Three ethyl 5-amino-1-aryl-1H -imidazole-4-carboxylates: hydrogen-bonded supramolecular structures in one, two and three dimensionsACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2007Marilia S. Costa The molecules of ethyl 5-amino-1-(4-cyanophenyl)-1H -imidazole-4-carboxylate, C13H12N4O2, are linked into a chain of alternating R22(10) and R44(34) rings by a combination of N,H,N and C,H,N hydrogen bonds. In ethyl 5-amino-1-(4-chlorophenyl)-1H -imidazole-4-carboxylate, C12H12ClN3O2, where the ethyl group is disordered over two sets of sites, a combination of N,H,O, N,H,N, C,H,N and C,H,,(arene) hydrogen bonds links the molecules into complex sheets. Two intermolecular hydrogen bonds, one each of N,H,N and C,H,O types, link the molecules of ethyl 5-amino-1-(2,6-difluorophenyl)-1H -imidazole-4-carboxylate, C12H11F2N3O2, into a continuous three-dimensional framework structure. [source] 4-Iodo- N,N -bis(2-nitrophenylsulfonyl)aniline: a three-dimensional framework structure built from six independent C,H,O hydrogen bondsACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2006John N. Low In the title compound [systematic name: 4-iodophenylimino bis(2-nitrobenzenesulfinate)], C18H12IN3O8S2, where the molecules do not exhibit even approximate local symmetry, the molecules are linked into a complex three-dimensional structure by six independent C,H,O hydrogen bonds, which utilize O atoms in nitro and sulfonyl groups as the acceptors. [source] 2,4-Dinitrophenylhydrazine, redetermined at 120,K: a three-dimensional framework built from N,H,O, N,H,(O)2, N,H,,(arene) and C,H,O hydrogen bondsACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2006James L. Wardell In the title compound, C6H6N4O4, the bond distances indicate significant bond fixation, consistent with charge-separated polar forms. The molecules are almost planar and there is an intramolecular N,H,O hydrogen bond. The molecules are linked into a complex three-dimensional framework structure by a combination of N,H,O, N,H,(O)2, N,H,,(arene) and C,H,O hydrogen bonds. [source] 7-Amino-2,5-dimethylpyrazolo[1,5- a]pyrimidine hemihydrate redetermined at 120,K: a three-dimensional hydrogen-bonded frameworkACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2006Jaime Portilla In the title compound, C8H10N4·0.5H2O, where the water molecules lie on twofold rotation axes in the space group C2, the components are linked by three hydrogen bonds, one each of O,H,N, N,H,N and N,H,O types, into a complex three-dimensional framework structure. [source] Tetraaquacobalt(II) bis[vanadyl(IV) phosphate], [Co(H2O)4][VO(PO4)]2ACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2003Bi-Zhou Lin The structure of [Co(H2O)4][VO(PO4)]2 is composed of [VO(PO4)] layers and interlayer tetrahydrated Co2+ ions. Alternating VO5 square pyramids and PO4 tetrahedra share O-atom vertices, thus forming the vanadyl phosphate layers. Two vanadyl oxo groups from neighbouring layers are coordinated to each Co atom in a trans fashion, with Co,O distances of 2.157,(4),Å, thus generating a three-dimensional framework structure. [source] (NH4)2ZrGe3O9: a new microporous zirconogermanateACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2003Zhicheng Liu A new microporous zirconogermanate, diammonium zirconium trigermanate, (NH4)2ZrGe3O9 (FDZG-2), analogous to wadeite (K2ZrSi3O9), was hydrothermally synthesized using ZrO(NO3)2·2H2O as the source of zirconium and 1,4-diaminobutane as a structure-directing agent. Single-crystal X-ray diffraction analysis reveals that the framework structure is built up of cyclic trigermanate units crosslinked by ZrO6 octahedra. The Zr atom lies at a site with symmetry and the unique N atom of the ammonium ion lies at a site with threefold symmetry. Large cages are observed, with two NH4+ cations in each. The structure contains intersecting six- and three-membered ring (6MR and 3MR) channels, but only the 6MR channels can accommodate the NH4+ ions. [source] Zn[BPO4(OH)2]: A Zinc Borophosphate with the Rare Moganite-Type TopologyCHEMISTRY - A EUROPEAN JOURNAL, Issue 6 2008Ya-Xi Huang Dr. Abstract A novel zinc borophosphate Zn[BPO4(OH)2] with moganite-type topology (a rare polymorph of silica) has been prepared from a mixture of ZnO, B2O3, and P2O5 by hydrothermal treatment at 443,K. The crystal structure was determined from single-crystal X-ray data (orthorhombic, Pbcn (no. 60), a=915.07(3), b=897.22(3), c=1059.19(3),pm, V=869.62(5)×106,pm3, Z=8, R1=0.028, wR2=0.075). The crystal structure comprises unbranched vierer -single borophosphate chains running along [010] and interconnected via ZnO2(OH)2 -tetrahedra by sharing common vertices. The resulting topology of the three-dimensional tetrahedral framework structure is described by the Schläfli symbol (42.62.82)(4.64.8)2. Although showing Zn in a tetrahedral coordination, the title compound does not belong to the group of zincoborophosphates but is a special case of a borophosphate containing vierer single rings of tetrahedra with the sequence Zn-B-Zn-P. [source] Three-Dimensional Lanthanide(III),Copper(II) Compounds Based on an Unsymmetrical 2-Pyridylphosphonate Ligand: An Experimental and Theoretical StudyCHEMISTRY - A EUROPEAN JOURNAL, Issue 17 2007Yun-Sheng Ma Abstract Based on an unsymmetrical 2-pyridylphosphonate ligand, two types of LnIII,CuII compounds with three-dimensional structures were obtained under hydrothermal conditions, namely, Ln2Cu3(C5H4NPO3)6,4,H2O (1,Ln; Ln=La, Ce, Pr, Nd) and Ln2Cu3(C5H4NPO3)6 (2,Ln; Ln=Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho). Compounds 1,Ln are isostructural and crystallize in chiral cubic space group I213. In these structures, each Ln ion is nine-coordinate and has a tricapped triprismatic geometry, while each Cu center is six-coordinate with an octahedral environment. The {LnO9} polyhedra and {CuN2O4} octahedra are connected by edge sharing to form an inorganic open framework structure with a 3-connected 10-gon (10,3) topology in which the Ln and Cu atoms are alternately linked by the phosphonate oxygen atoms. Compounds 2,Ln are isostructural and crystallize in trigonal space group R. In these structures, the {LnO6} octahedra are triply bridged by the {CPO3} tetrahedra by corner sharing to form an infinite chain along the c axis. Each chain is connected to its six equivalents through corner sharing of {CPO3} tetrahedra and {CuN2O2} planes to form a three-dimensional framework structure in which the Ln and Cu atoms are linked purely by O-P-O units. The formation of these two types of structures is rationalized by quantum chemical calculations, which showed that both the lanthanide contraction and the electron configuration of CuII play important roles. When CuII was replaced by ZnII, only the first type of compounds resulted. The magnetic properties of complexes 1,Ln and 2,Ln were investigated. The nature of LnIII,CuII (Ln=Ce, Pr, Nd) interactions is illustrated by comparison with their LnIII,ZnII analogues. [source] Germanates of 1D Chains, 2D Layers, and 3D Frameworks Built from Ge,O Clusters by Using Metal-Complex Templates: Host,Guest Symmetry and Chirality TransferCHEMISTRY - AN ASIAN JOURNAL, Issue 10 2007Guang-Zhen Liu Abstract The self-assembly of Ge,O polyhedra by metal-complex templates leads to initial examples of open germanate structures under mild solvothermal conditions. These materials are constructed from Ge,O cluster building bocks (Ge7X19 (X=O, OH, or F) or Ni@Ge14O24(OH)3) and span the full range of dimensionalities from 1D chains of Ge7O13(OH)2F3,Cl,2[Ni(dien)2] (FJ- 6) to 2D layers of Ge7O14F3,0.5[In(dien)2],0.5H3dien, 2H2O (1) and 3D frameworks of Ni@ Ge14O24(OH)3,2[Ni(L)3] (FJ- 1,a/FJ- 1,b) (dien=diethylenetriamine, L=ethylenediamine (en) or 1,2-diaminopropane (enMe)). The Ge7X19 cluster in FJ- 6 and 1 is formed by condensation of four GeX4 tetrahedra, two GeX5 trigonal bipyramids, and one GeX6 octahedron with a ,3 -O atom at the center of the cluster, whereas the Ni@ Ge14O24(OH)3 cluster in FJ- 1,a/FJ- 1,b is formed by condensation of nine peripheral GeO4 tetrahedra and five interior GeO3Ni units with one ,5 -Ni atom at the center of the cluster. FJ- 6 is characterized by a pair of racemic Ge7O14(OH)2F3 cluster chains and represents only one example of 1D germanates; 1 exhibits unique germanate layers with uniform 10-membered-ring apertures encapsulating an unknown indium complex, and the framework structure of FJ- 1,a/FJ- 1,b with large 24-membered-ring channels is the first example of porous materials that contain metal,metal bonds (Ge2+Ni+). These initial examples of germanates from metal-complex templates provide a useful model system for understanding the mechanisms of host,guest interactions, which may further facilitate the design and development of new porous materials "on demand". It is shown that the symmetry and configuration of the guest metal complex can be imprinted onto the host inorganic framework through hydrogen bonding between host and guest. [source] Elastic and inelastic drift performance optimization for reinforced concrete buildings under earthquake loadsEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 8 2004Chun-Man Chan Abstract This paper presents an effective optimization technique for the elastic and inelastic drift performance design of reinforced concrete buildings under response spectrum loading and pushover loading. Attempts have been made to develop an automatic optimal elastic and inelastic drift design of concrete framework structures. The entire optimization procedure can be divided into elastic design optimization and inelastic design optimization. Using the principle of virtual work, the elastic drift response generated by the response spectrum loading and the inelastic drift response produced by the non-linear pushover loading can be explicitly expressed in terms of element sizing design variables. The optimization methodology for the solution of the explicit design problem of buildings is fundamentally based on the Optimality Criteria approach. One ten-story, two-bay building frame example is presented to illustrate the effectiveness and practicality of the proposed optimal design method. While rapid convergence in a few design cycles is found in the elastic optimization process, relatively slow but steady and smooth convergence of the optimal performance-based design is found in the inelastic optimization process. Copyright © 2004 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||