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Zigzag Chains (zigzag + chain)
Kinds of Zigzag Chains Terms modified by Zigzag Chains Selected AbstractsNickel Complexes and Cobalt Coordination Polymers with Organochalcogen (S, Se) Ligands Bearing an N -Methylimidazole Moiety: Syntheses, Structures, and Properties,EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 26 2008Wei-Guo Jia Abstract The organochalcogen ligands (S, Se) derived from 3-methylimidazole-2-thione/selone groups mbit (2a), mbis (2b), ebit (2c), and ebis (2d) [mbit = 1,1,-methylenebis(1,3-dihydro-3-methyl-2H -imidazole-2-thione), mbis = 1,1,-methylenebis(1,3-dihydro-3-methyl-2H -imidazole-2-selone), ebit = 1,1,-(1,2-ethanediyl)bis(1,3-dihydro-3-methyl-1H -imidazole-2-thione), ebis = 1,1,-(1,2-ethanediyl)bis(1,3-dihydro-3-methyl-1H -imidazole-2-selone)] were synthesized and characterized. Mononuclear NiII complexes NiBr2mbit (3a), NiBr2mbis (3b), NiBr2ebit (3c), and NiBr2ebis (3d) were obtained by the reactions of Ni(PPh3)2Br2 with 2a, 2b, 2c, and 2d, respectively. However, when the corresponding ligands 2a, 2b, 2c, and 2d were treated with CoCl2 in thf solution CoII 1D coordination polymers (CoCl2mbit)n (4a), (CoCl2mbis)n (4b), (CoCl2ebit)n (4c), and (CoCl2ebis)n (4d) were obtained. All compounds were fully characterized by IR spectroscopy and elemental analysis. The crystal structures of 2c, 3a, 3b, 3c, 4a, 4b, and 4c were determined by X-ray crystallography. The local geometry around the nickel atom in complexes 3a,c was distorted tetrahedron with coordinated S(Se) and two Br atoms, and the organochalcogen ligands form an eight- or a nine-membered ring with the nickel atom included. The cobalt atom coordination polymers 4a and 4b coexist as left-handed and right-handed helical chains, but 4c formed a zigzag chain with a CH3CN solvent molecule taken up in the channel structure. After activation with methylaluminoxane (MAO), the nickel complexes exhibited high activities for addition polymerization of norbornene (1.42,×,108 g,PNBmol,1,Nih,1 for 3a). The effects of the Al/Ni ratio, reaction temperature, and reaction time to norbornene polymerization were also investigated.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Inclusion Complexes for Use in Room-Temperature Gas-Sensor DesignEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 33 2007Liwei Mi Abstract The inclusion complex [{Co(bpy)(H2O)4}·(fcds)]n (1), which has been constructed using the guest molecule ferrocene-1,1,-disulfonate (fcds), the bridging ligand 4,4,-bipyridine (bpy) and d7 Co2+, contains an infinite zigzag chain formed by the central CoII ion and the bridging bpy ligand. Guest fcds molecules lie between two adjacent zigzag chains. The highly conjugated structure of complex 1 means that it can be used as a metal-organic semiconductor, and it also shows a high response to liquefied petroleum gas (LPG) and ethanol/petroleum ether (EP) at room temperature. The inclusion complexes [{Co(bpp)2(H2O)2}·(fcds)·4H2O]n [2; bpp = 1,3-bis(4-pyridyl)propane] and [{Zn(bpy)(H2O)4}·(fcds)]n (3), on the other hand, cannot be employed as room-temperature gas sensors because they are insulators. The electrical resistivity of inclusion complex [{Ni(bpy)(H2O)4}·(fcds)]n (4) is 621 M,, whereas that of [{Co(bpy)(H2O)4}SO4·(4-abaH)2·3H2O]n (5) (4-abaH = 4-aminobenzoic acid) is only 137 M,. This means that the semi-conducting properties of such inclusion complexes depend on both the conjugated structure and the central metal ions. Furthermore, conjugated inclusion complexes with an odd number of electrons could be useful for the design of highly selective room-temperature gas sensors.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Designed Assembly and Structures and Photoluminescence of a New Class of Discrete ZnII Complexes of 1H -1,10-Phenanthroline-2-oneEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 17 2006Jie-Peng Zhang Abstract The hydrothermal reaction of 1H -1,10-phenanthroline-2-one (Hophen), zinc acetate, benzoic acid (Hba), and triethylamine (3.0 mL) yields the tetranuclear complex [Zn4(,3 -OH)2(ophen)4(ba)2] (2), which features a chair-like Zn4(,3 -OH)2 cluster with two ba ligands centrosymmetrically oriented. [(OAc){Zn3(,3 -OH)(ophen)3}(ox){Zn3(,3 -OH)(ophen)3}(OAc)] (3; ox = oxalate) was isolated when less triethylamine (1.0 mL) was used. Two Zn3(,3 -OH)(ophen)3 clusters in 3 are linked together by an oxalate to form a dumbbell-like structure in which the acetate and oxalate ligands point outward from the Zn3(,3 -OH)(ophen)3 cluster with an acute bending angle. A geometric analysis reveals that Zn3(,3 -OH)(ophen)3 and dicarboxylate with an obtuse bending angle cannot form an infinite zigzag chain, whereas the ring isomer can. With isophthalate (ipa), thiophene-2,5-dicarboxylate (tda), and 4,4,-oxybis(benzoate) (oba) instead of the acetate of 3 three new complexes, namely [{Zn3(,3 -OH)(ophen)3}(ipa)2{Zn3(,3 -OH)(ophen)3}]·0.5H2O (4), [{Zn3(,3 -OH)(ophen)3}(tda)2{Zn3(,3 -OH)(ophen)3}] (5), and [{Zn3(,3 -OH)(ophen)3}(oba)2{Zn3(,3 -OH)(ophen)3}] (6), were obtained in which two Zn3(,3 -OH)(ophen)3 clusters are linked by a pair of ipa, tda, or oba ligands to form isostructural, cluster-based 2:2 metallomacrocycles. Photoluminescence studies of 2,6 revealed that their luminescent properties are derived from ophen-based ,-,* excited states. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] catena -Poly[bis(trimethylphenylammonium) [hexa-,-chlorido-dichloridotricuprate(II)]]: an alternating zigzag chain of CuCl4 and Cu2Cl6 complexesACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2010Marcus R. Bond The title compound, {(C9H14N)2[Cu3Cl8]}n, consists of parallel chains of alternating quasiplanar Cu2Cl6 and planar CuCl4 complexes separated by trimethylphenylammonium cations. Both inorganic complexes possess inversion symmetry. Pairs of neighboring chloride ions of the CuCl4 complex each form a symmetric bridge and an asymmetric bridge to Cu2Cl6 complexes on either side. The Cu2Cl6 complex contains two symmetric chloride bridges between the copper cations with a terminal chloride bound to each five-coordinated CuII ion. The CuCl4 complex completes its coordination environment by forming two long semicoordinate contacts to the bridging chloride ions of neighboring Cu2Cl6 complexes. The use of the bridging rather than the terminal chloride ions to form semicoordinate contacts generates a new zigzag chain structure that differs from the straight chain structures found for other A2Cu3Cl8 compounds. The zigzag chain structure is adopted so as to conform to the shorter repeat distance dictated by stacking of the organic cations. [source] Poly[[diaqua(,3 -3-nitrophthalato)calcium(II)] monohydrate]ACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2009Ming-Lin Guo The title 3-nitrophthalate,calcium coordination polymer, {[Ca(C8H3NO6)(H2O)2]·H2O}n, crystallizes as a one-dimensional framework. The CaII centre has a distorted pentagonal,bipyramidal geometry, being seven-coordinated by five O atoms from three different 3-nitrophthalate groups and by two water molecules, resulting in a one-dimensional zigzag chain along the a -axis direction by the interconnection of the four O atoms from the two carboxylate groups. There is a D3 water cluster composed of the coordinated and the solvent water molecules within such chains. Adjacent chains are aggregated into two-dimensional layers via hydrogen bonds in the c -axis direction. The whole three-dimensional structure is further stabilized by weak O,H...O hydrogen bonds between the O atoms of the nitro group and the water molecules. [source] Hydrogen-bond-directed supramolecular arrays in 4,4,-bipyridinium tetrachloroterephthalate dihydrate and bis(1,10-phenanthrolinium) tetrachloroterephthalate tetrachloroterephthalic acid trihydrateACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2009Ming-Yang He The title compounds, C10H10N22+·C8Cl4O42,·2H2O, (I), and 2C12H9N2+·C8Cl4O42,·C8H2Cl4O4·3H2O, (II), both crystallize as charge-transfer organic salts with the dianionic or neutral acid components lying on inversion centres. The acid and base subunits in (I) arrange alternately to generate a linear tape motif via N,H...O hydrogen bonds; these tapes are further combined into a three-dimensional architecture through multiple O,H...O and C,H...O interactions involving solvent water molecules. In contrast, the neutral and anionic acid components in (II) are linked to form a zigzag chain by means of O,H...O hydrogen bonds between acid groups, with dangling 1,10-phenanthrolinium units connected to these chains by carboxylate,pyridinium interactions with R22(7) hydrogen-bond notation. Adjacent chains are further extended to result in a two-dimensional corrugated layer network via,,, interactions. Inter-ion Cl...O interactions are also found in both (I) and (II). [source] Codeine dihydrogen phosphate hemihydrateACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2009Christoph Langes The cation of the title structure [systematic name: (5,,6,)-6-hydroxy-7,8-didehydro-4,5-epoxy-3-methoxy-17-methylmorphinanium dihydrogen phosphate hemihydrate], C18H22NO3+·H2PO4,·0.5H2O, has a T-shaped conformation. The dihydrogen phosphate anions are linked by O,H...O hydrogen bonds to give an extended ribbon chain. The codeine cations are linked together by O,H...O hydrogen bonds into a zigzag chain. There are also N,H...O bonds between the two types of hydrogen-bonded units. Addditionally, they are connected to one another via O...H,O,H...O bridging water molecules. The asymmetric unit contains two codeine hydrogen cations, two dihydrogen phosphate anions and one water molecule. This study shows that the water molecules are firmly bound within a complex three-dimensional hydrogen-bonded framework. [source] Cocrystallization of two tautomers: 4-(1-{[4-(dimethylamino)benzylidene]hydrazono}ethyl)benzene-1,3-diol and 6-[(E)-1-{[4-(dimethylamino)benzylidene]hydrazino}ethylidene]-3-hydroxycyclohexa-2,4-dien-1-one (1/1)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2009Zhen-Hua Wu Two different tautomeric forms of a new Schiff base, C17H19N3O2·C17H19N3O2, are present in the crystal in a 1:1 ratio, namely the enol,imine form 4-(1-{[4-(dimethylamino)benzylidene]hydrazono}ethyl)benzene-1,3-diol and the keto,amine form 6-[(E)-1-{[4-(dimethylamino)benzylidene]hydrazino}ethylidene]-3-hydroxycyclohexa-2,4-dien-1-one. The tautomers are formed by proton transfer between the hydroxy O atom and the imine N atom and are hydrogen bonded to each other to form a one-dimensional zigzag chain along the crystallographic b axis via intermolecular hydrogen bonds. [source] Two transition metal coordination polymers of the 7,7,8,8-tetracyanoquinodimethane dianion (TCNQ2,)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2009Guangbin Wang Each of the two novel title transition metal coordination polymers, namely catena -poly[[bis{[tris(2-pyridylmethyl)amine]cobalt(II)}-,4 -7,7,8,8-tetracyanoquinodimethanide(2,)] bis[7,7,8,8-tetracyanoquinodimethanide(1,)] methanol disolvate], {[Co2(C12H4N4)(C18H18N4)2](C12H4N4)2·2CH3OH}n, (I), and catena -poly[[[[tris(2-pyridylmethyl)amine]iron(II)]-,2 -7,7,8,8-tetracyanoquinodimethanide(2,)] methanol solvate], {[Fe(C12H4N4)(C18H18N4)]·CH3OH}n, (II), contains ,4 -TPA and cis -bridging TCNQ2, ligands [TPA is tris(2-pyridylmethyl)amine and TCNQ is 7,7,8,8-tetracyanoquinodimethane], but the two compounds adopt entirely different structural motifs. Compound (I) consists of a ribbon coordination polymer featuring ,4 -TCNQ2, radical anion ligands bridging four different octahedral CoII centers. Each formula unit of the polymer is flanked by two uncoordinated TCNQ, anions and two methanol solvent molecules. All three TCNQ anions have crystallographic inversion symmetry. In (II), the 21 symmetry operator generates a one-dimensional zigzag chain of octahedral FeII centers with ,2 -TCNQ2, bridges. A methanol solvent molecule forms hydrogen bonds to one of the terminal N atoms of the bridging TCNQ2, dianion. To the best of our knowledge, these are the first examples of one-dimensional coordination polymers forming from cis coordination of two TCNQ ligands to octahedral metal centers. [source] Synthetic aenigmatite analog Na2(Mn5.26Na0.74)Ge6O20: structure and crystal chemical considerationsACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2008Günther J. Redhammer Disodium hexamanganese(II,III) germanate is the first aenigmatite-type compound with significant amounts of manganese. Na2(Mn5.26Na0.74)Ge6O20 is triclinic and contains two different Na positions, six Ge positions and 20 O positions (all with site symmetry 1 on general position 2i of space group P). Five out of the seven M positions are also on general position 2i, while the remaining two have site symmetry (Wyckoff positions 1f and 1c). The structure can be described in terms of two different layers, A and B, stacked along the [011] direction. Layer A contains pyroxene-like chains and isolated octahedra, while layer B is built up by slabs of edge-sharing octahedra connected to one another by bands of Na polyhedra. The GeO4 tetrahedra show slight polyhedral distortion and are among the most regular found so far in germanate compounds. The M sites of layer A are occupied by highly charged (trivalent) cations, while in layer B a central pyroxene-like zigzag chain can be identified, which contains divalent (or low-charged) cations. This applies to the aenigmatite-type compounds in general and to the title compound in particular. [source] Hydrogen-bonded supramolecule of N,N,-bis(4-pyridylmethyl)oxalamide and a zigzag chain structure of catena -poly[[[dichloridocobalt(II)]-,- N,N,-bis(4-pyridylmethyl)oxalamide-,2N4:N4,] hemihydrate]ACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2007Gene-Hsiang Lee N,N,-Bis(4-pyridylmethyl)oxalamide, C14H14N4O2, exists as a dimer which is extended into a two-dimensional network with other dimers through pyridine,amide hydrogen bonds. The crystal structure of the title coordination polymer, {[CoCl2(C14H14N4O2)]·0.5H2O}n, features a one-dimensional zigzag chain, in which the cobalt ion sits at a twofold symmetry position and adopts a tetrahedral geometry, and the bridging ligand lies on an inversion center and connects to CoII ions in a bis-monodentate mode. Furthermore, two interwoven chains create a cavity of ca 8.6 × 8.6,Å, which produces a three-dimensional channel. Water molecules are held in the channel by hydrogen bonds. [source] Benzene-1,2,4,5-tetracarboxylic acid,trans -cinnamamide,(1/2)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2000Hiroyuki Hosomi In the title adduct, C10H6O8·2C9H9NO, benzene-1,2,4,5-tetracarboxylic acid has a crystallographic twofold axis parallel to b and forms a flat zigzag chain along c linked by O, H,O cyclic hydrogen bonds with cinnamamide molecules. [source] Synthesis and Characterization of Three Diverse Coordination Frameworks under Co-ligand InterventionCHINESE JOURNAL OF CHEMISTRY, Issue 2 2009Ping LIU Abstract The chelating organic ligands of 2,2,-bipyridine (2,2,-bipy), di(pyrid-2-yl)amine (dpa) and 2,6-di(pyrid-2-ylamino)pyridine (dpap) were respectively applied to react with H2fum (fumaric acid) and copper salts, affording three different complexes [Cu2(fum)(2,2,-bipy)4]·2ClO4 (1), [Cu2(µ-OH)2(fum)(dpa)2]·2H2O (2) and [Cu(SO4)(H2O)(dpap)]·H2O (3). These complexes were determined by single-crystal X-ray diffraction. Each penta-coordinated Cu(II) ion exhibits a distorted trigonal bipyramidal geometry in 1. The fum ligand links copper ions to form a dinuclear copper unit. While in 2, the fum ligands connect [Cu2(µ-OH)2(dpa)2] unit to construct a 1D zigzag chain. Unexpectedly, when dpap instead of dpa was used under the same conditions, only one mononuclear complex 3 was formed. Crystal packings show that 1,3 form 3D supramolecular architectures through non-covalent interactions (multiple hydrogen bonds and C,H··· ,/,-, interactions). In addition, the study of the magnetic property reveals dominating ferromagnetic interactions between Cu(II) atoms in 1. [source] Crystal Structure, Thermal Stability and Luminescence of Coordination Polymer [Cd(BBP)(p -PDOA)]nCHINESE JOURNAL OF CHEMISTRY, Issue 8 2007Yan Yang Abstract Hydrothermal reaction of Cd(NO3)2·4H2O with bbp and p -PDOAH2 at 140 °C yielded a novel 1D cadmium(II) coordination polymer, [Cd(bbp)(p -PDOA)]n (bbp2,6-bis(benzimidazol-2-yl)pyridine, p -PDOAp -phenylenedioxy- diacetate dianion), in which CdN3O4 pentagonal bipyramids were linked by p -PDOA ligands in a bis-bidentate mode to construct a zigzag chain with the adjacent Cd···Cd distance of 1.14(1) nm. There exists a 2D supramolecular network linked by ,-, stacking with a face-to-face distance of 0.35(1) nm between the 2,6-bis(benzimidazol-2-yl) pyridine ligands and hydrogen-bonding interactions (0.27(4) nm). A 3D supramolecular network was further constructed by these non-covalent interactions between the zippers. The TG/DTG showed that its chain skeleton was thermally stable up to 389 °C and the blue fluorescent emission of the complex was determined at 428 nm in a solid state with its long decay lifetime of 7.24 ns. [source] Synthesis and crystal strcucture of two zinc inclusion complexesCRYSTAL RESEARCH AND TECHNOLOGY, Issue 8 2008Min-Le Han Abstract X-ray single crystals of these two inclusion complexes, [Zn(H2O)4L2]·(4-amino-1-naphthalene sulfonate)2 (L = 1,3-bis(4-pyridyl) propane), 1, and [Zn(H2O)(bipy)2]·(4-amino-1-naphthalene sulfonate)(NO3) (bipy = 4,4'-bipyridine), 2 were achieved by the reaction of Zn(NO3)2 and 4-amino-1-naphthalene sulfonate to 1,3-bis(4-pyridyl) propane and 4,4'-bipyridine, respectively. As inclusion complexes, the cationic components of 1 and 2 were formed by two infinite zigzag chains, while, 4-amino-1-naphthalene sulfonate made up the anionic parts of these two complexes. Thus, the whole molecules of these two complexes are neuter. Numous hydrogen bonds could be found in these two inclusion complexes, which help them to form three-dimensional solid-state packing structure architectures. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Thermal Decomposition Reactions as a Tool for the Synthesis of New Thermodynamic Metastable Modifications: Synthesis, Structures, and Properties of (Formato)nickel(II) Coordination Polymers Based on 4,4,-BipyridineEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 12 2010Jan Boeckmann Abstract The reaction of nickel formate with 4,4,-bipyridine (bipy) in aqueous solution at room temperature leads to the formation of the hydrated compound [Ni(HCO2)2(H2O)(bipy)·4H2O]n (1) reported recently. On heating, compound 1 decomposes into the new anhydrous compound of composition [Ni(HCO2)2(bipy)]n (2II), which decomposes on further heating. Interestingly, if the anhydrous compound is prepared from solution, a new modification 2I is obtained. Investigations on the stability of both forms show that modification 2I presents the thermodynamically most stable form between room and decomposition temperature, whereas modification 2II, which can only be prepared by thermal decomposition, is metastable. In the crystal structure of 2I, the Ni2+ cations are coordinated by four ,2 - anti,anti bridging formato anions and two bridging ,2 -bipy ligands in a slightly distorted octahedralgeometry. The formato anions bridge the metal cations in zigzag chains, which are further connected by ,2 - anti,anti formato anions and bipy ligands to give a three-dimensional coordination network. IR spectroscopic investigations on the metastable form 2II also indicate that all formato anions act as bridging ligands. Magnetic measurements of the hydrated and anhydrous compounds reveal different behavior with a ferromagnetic ordering for compound 2I and an antiferromagnetic ordering for compound 1. For form 2II, only Curie,Weiss paramagnetism was found. [source] Inclusion Complexes for Use in Room-Temperature Gas-Sensor DesignEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 33 2007Liwei Mi Abstract The inclusion complex [{Co(bpy)(H2O)4}·(fcds)]n (1), which has been constructed using the guest molecule ferrocene-1,1,-disulfonate (fcds), the bridging ligand 4,4,-bipyridine (bpy) and d7 Co2+, contains an infinite zigzag chain formed by the central CoII ion and the bridging bpy ligand. Guest fcds molecules lie between two adjacent zigzag chains. The highly conjugated structure of complex 1 means that it can be used as a metal-organic semiconductor, and it also shows a high response to liquefied petroleum gas (LPG) and ethanol/petroleum ether (EP) at room temperature. The inclusion complexes [{Co(bpp)2(H2O)2}·(fcds)·4H2O]n [2; bpp = 1,3-bis(4-pyridyl)propane] and [{Zn(bpy)(H2O)4}·(fcds)]n (3), on the other hand, cannot be employed as room-temperature gas sensors because they are insulators. The electrical resistivity of inclusion complex [{Ni(bpy)(H2O)4}·(fcds)]n (4) is 621 M,, whereas that of [{Co(bpy)(H2O)4}SO4·(4-abaH)2·3H2O]n (5) (4-abaH = 4-aminobenzoic acid) is only 137 M,. This means that the semi-conducting properties of such inclusion complexes depend on both the conjugated structure and the central metal ions. Furthermore, conjugated inclusion complexes with an odd number of electrons could be useful for the design of highly selective room-temperature gas sensors.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] First Examples of Ternary Lanthanide 2,2,-Diphenyldicarboxylate Complexes: Hydrothermal Syntheses and Structures of Lanthanide Coordination Polymers of 2,2,-Diphenyldicarboxylic Acid and 1,10-PhenanthrolineEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 19 2003Yibo Wang Abstract In the four new lanthanide coordination polymers {[La2(2,2,-dpdc)3(phen)(H2O)]·2H2O}n (1), [Eu2(2,2,-dpdc)3(phen)(H2O)2]n (2), {[Ln2(2,2,-dpdc)3(phen)2(H2O)2]·4H2O}n [Ln = Tb (3), Yb (4)] (2,2,-dpdc = 2,2,-diphenyldicarboxylate, phen = 1,10-phenanthroline), prepared by hydrothermal synthesis, the 2,2,-dpdc dianion affords tetradentate, pentadentate, and hexadentate coordination modes. Complex 1 is a two-dimensional network of infinite 1-D chains assembled through ,,, interactions, with nine- and ten-coordinate La3+, and arranged in wave-like layers. In 2, Eu3+ possesses nine- and ten-coordinate geometries bridged by 2,2,-dpdc ligands to give a 3-D structure. The isomorphous complexes 3 and 4, in which Tb3+ and Yb3+ ions are both nine-coordinate, have two-dimensional structures of 1-D zigzag chains stacked via hydrogen bonds and ,,, interactions of phen molecules. The high-resolution emission spectrum of 2 shows two Eu3+ ion sites, which is consistent with the results of the X-ray crystal structure analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] The crystal structure of perdeuterated methanol hemiammoniate (CD3OD·0.5ND3) determined from neutron powder diffraction data at 4.2 and 180,KJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 2 2010A. D. Fortes The crystal structure of perdeuterated methanol hemiammoniate, CD3OD·0.5ND3, has been solved from neutron powder diffraction data collected at 4.2 and 180,K. The structure is orthorhombic, space group Pn21a (Z = 4), with unit-cell dimensions a = 12.70615,(16), b = 8.84589,(9), c = 4.73876,(4),Å, V = 532.623,(8),Å3 [,calc = 1149.57,(2),kg,m,3] at 4.2,K, and a = 12.90413,(16), b = 8.96975,(8), c = 4.79198,(4),Å, V = 554.656,(7),Å3 [,calc = 1103.90,(1),kg,m,3] at 180,K. The crystal structure was determined by ab initio methods from the powder data; atomic coordinates and isotropic displacement parameters were subsequently refined by the Rietveld method to Rp, 2% at both temperatures. The crystal structure comprises a three-dimensionally hydrogen-bonded network in which the ND3 molecules are tetrahedrally coordinated by the hydroxy moieties of the methanol molecule. This connectivity leads to the formation of zigzag chains of ammonia,hydroxy groups extending along the c axis, formed via N,D···O hydrogen bonds; these chains are cross-linked along the a axis through the hydroxy moiety of the second methanol molecule via N,D···O and O,D···O hydrogen bonds. This `bridging' hydroxy group in turn donates an O,D···N hydrogen bond to ammonia in adjacent chains stacked along the b axis. The methyl deuterons in methanol hemiammoniate, unlike those in methanol monoammoniate, do not participate in hydrogen bonding and reveal evidence of orientational disorder at 180,K. The relative volume change on warming from 4.2 to 180,K, ,V/V, is + 4.14%, which is comparable to, but more nearly isotropic (as determined from the relative change in axial lengths, e.g.,a/a) than, that observed in deuterated methanol monohydrate, and very similar to what is observed in methanol monoammoniate. [source] Electron localization and emission mechanism in wurtzite (Al, In, Ga)N alloysPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 1 2010Qihang Liu Abstract The electronic structures of wurtzite InGaN and AlGaN alloys are investigated using the first-principle density functional theory calculation. The results indicate that some short In,N,In atomic chains and small In,N atomic condensates composed of a few In and N atoms can be randomly formed in InGaN alloys. The electrons at the top of valence bands can be effectively localized in the vicinity of the In,N,In zigzag chains (weak localization) and the In,N atomic condensates (strong localization). These localized electrons extremely enhance the emission efficiency of InGaN alloys. [source] One-dimensional surface states induced by segregated impurities at transition-metal surfacesPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 9 2006G. Trimarchi Abstract Using ab initio pseudopotential calculations, we have investigated the atomic and electronic structure of a c (3,2 × ,2) striped reconstruction, induced by segregated C impurities, at the Fe(001) surface. The segregated C atoms form zigzag chains, which in turn produce one-dimensional Fe surface states near the Fermi energy. We address the influence of the C chains on the local surface atomic geometry, local electrostatic potential, and local density of states, and discuss the formation mechanism of the one-dimensional surface states. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] 1,1,-Fc(4-C6H4CO2Et)2 and its unusual salt derivative with Z, = 5, catena -[Na+]2[1,1,-Fc(4-C6H4CO2,)2]·0.6H2O [1,1,-Fc = (,5 -(C5H4)2Fe]ACTA CRYSTALLOGRAPHICA SECTION B, Issue 2 2010John F. Gallagher The neutral diethyl 4,4,-(ferrocene-1,1,-diyl)dibenzoate, Fe[,5 -(C5H4)(4-C6H4CO2Et)]2 (I), yields (II) (following base hydrolysis) as the unusual complex salt poly[disodium bis[diethyl 4,4,-(ferrocene-1,1,-diyl)dibenzoate] 0.6-hydrate] or [Na+]2[Fe{,5 -(C5H4)-4-C6H4CO}2]·0.6H2O with Z, = 5. Compound (I) crystallizes in the triclinic system, space group , with two molecules having similar geometry in the asymmetric unit (Z, = 2). The salt complex (II) crystallizes in the orthorhombic system, space group Pbca, with the asymmetric unit comprising poly[decasodium pentakis[diethyl 4,4,-(ferrocene-1,1,-diyl)dibenzoate] trihydrate] or [Na+]10[Fe{,5 -(C5H4)-4-C6H4CO}2]5·3H2O. The five independent 1,1,-Fc[(4-C6H4CO2),]2 dianions stack in an offset ladder (stepped) arrangement with the ten benzoates mutually oriented cisoid towards and bonded to a central layer comprising the ten Na+ ions and three water molecules [1,1,-Fc = ,5 -(C5H4)2Fe]. The five dianions differ in the cisoid orientations of their pendant benzoate groups, with four having their ,C6H4, groups mutually oriented at interplanar angles from 0.6,(3) to 3.2,(3)° (as ,..., stacked C6 rings) and interacting principally with Na+ ions. The fifth dianion is distorted and opens up to an unprecedented ,C6H4, interplanar angle of 18.6,(3)° through bending of the two 4-C6H4CO2 groups and with several ionic interactions involving the three water molecules (arranged as one-dimensional zigzag chains in the lattice). Overall packing comprises two-dimensional layers of Na+ cations coordinated mainly by the carboxylate O atoms, and one-dimensional water chains. The non-polar Fc(C6H4)2 groups are arranged perpendicular to the layers and mutually interlock through a series of efficient C,H..., stacking contacts in a herringbone fashion to produce an overall segregation of polar and non-polar entities. [source] Incommensurately modulated lanthanide coinage-metal diarsenides.ACTA CRYSTALLOGRAPHICA SECTION B, Issue 5 2009GdCuAs2, GdAu1,,As2 and TbAu1,,As2 crystallize as incommensurately modulated variants of the HfCuSi2 type. Structure models have been developed in the monoclinic superspace group P121/m1(,0,)00 (No. 11.1). The components of the modulation wavevectors q = ,a* + 0b* + ,c* are , = 0.04,(1) and , = 0.48,(1) for GdCuAs2, , = 0.03,(1) and , = 0.48,(1) for GdAu1,,As2 and , = 0.02,(1) and , = 0.46,(1) for TbAu1,,As2. The predominant effect of the positional modulation is the distortion of a square net of arsenic atoms, which results in planar zigzag chains. Rod groups and layer groups of the respective structure motifs are identified and discussed. [source] Structural comparison of three N -(4-halogenophenyl)- N,-[1-(2-pyridyl)ethylidene]hydrazine hydrochloridesACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2010Julia Heilmann-Brohl 2-{1-[(4-Chloroanilino)methylidene]ethyl}pyridinium chloride methanol solvate, C13H13ClN3+·Cl,·CH3OH, (I), crystallizes as discrete cations and anions, with one molecule of methanol as solvent in the asymmetric unit. The N,C,C,N torsion angle in the cation indicates a cis conformation. The cations are located parallel to the (02) plane and are connected through hydrogen bonds by a methanol solvent molecule and a chloride anion, forming zigzag chains in the direction of the b axis. The crystal structure of 2-{1-[(4-fluoroanilino)methylidene]ethyl}pyridinium chloride, C13H13FN3+·Cl,, (II), contains just one anion and one cation in the asymmetric unit but no solvent. In contrast with (I), the N,C,C,N torsion angle in the cation corresponds with a trans conformation. The cations are located parallel to the (100) plane and are connected by hydrogen bonds to the chloride anions, forming zigzag chains in the direction of the b axis. In addition, the crystal packing is stabilized by weak ,,, interactions between the pyridinium and benzene rings. The crystal of (II) is a nonmerohedral monoclinic twin which emulates an orthorhombic diffraction pattern. Twinning occurs via a twofold rotation about the c axis and the fractional contribution of the minor twin component refined to 0.324,(3). 2-{1-[(4-Fluoroanilino)methylidene]ethyl}pyridinium chloride methanol disolvate, C13H13FN3+·Cl,·2CH3OH, (III), is a pseudopolymorph of (II). It crystallizes with two anions, two cations and four molecules of methanol in the asymmetric unit. Two symmetry-equivalent cations are connected by hydrogen bonds to a chloride anion and a methanol solvent molecule, forming a centrosymmetric dimer. A further methanol molecule is hydrogen bonded to each chloride anion. These aggregates are connected by C,H...O contacts to form infinite chains. It is remarkable that the geometric structures of two compounds having two different formula units in their asymmetric units are essentially the same. [source] Monohalogenated ferrocenes C5H5FeC5H4X (X = Cl, Br and I) and a second polymorph of C5H5FeC5H4IACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2009Alexander S. Romanov The structures of the three title monosubstituted ferrocenes, namely 1-chloroferrocene, [Fe(C5H5)(C5H4Cl)], (I), 1-bromoferrocene, [Fe(C5H5)(C5H4Br)], (II), and 1-iodoferrocene, [Fe(C5H5)(C5H4I)], (III), were determined at 100,K. The chloro- and bromoferrocenes are isomorphous crystals. The new triclinic polymorph [space group P, Z = 4, T = 100,K, V = 943.8,(4),Å3] of iodoferrocene, (III), and the previously reported monoclinic polymorph of (III) [Laus, Wurst & Schottenberger (2005). Z. Kristallogr. New Cryst. Struct.220, 229,230; space group Pc, Z = 4, T = 100,K, V = 924.9,Å3] were obtained by crystallization from ethanolic solutions at 253 and 303,K, respectively. All four phases contain two independent molecules in the unit cell. The relative orientations of the cyclopentadienyl (Cp) rings are eclipsed and staggered in the independent molecules of (I) and (II), while (III) demonstrates only an eclipsed conformation. The triclinic and monoclinic polymorphs of (III) contain nonbonded intermolecular I...I contacts, causing different packing modes. In the triclinic form of (III), the molecules are arranged in zigzag tetramers, while in the monoclinic form the molecules are arranged in zigzag chains along the a axis. Crystallographic data for (III), along with the computed lattice energies of the two polymorphs, suggest that the monoclinic form is more stable. [source] Insight into the structures of [M(C5H4I)(CO)3] and [M2(C12H8)(CO)6] (M = Mn and Re) containing strong I...O and ,(CO),,(CO) interactionsACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2009Alexander S. Romanov The compounds tricarbonyl(,5 -1-iodocyclopentadienyl)manganese(I), [Mn(C5H4I)(CO)3], (I), and tricarbonyl(,5 -1-iodocyclopentadienyl)rhenium(I), [Re(C5H4I)(CO)3], (III), are isostructural and isomorphous. The compounds [,-1,2(,5)-acetylenedicyclopentadienyl]bis[tricarbonylmanganese(I)] or bis(cymantrenyl)acetylene, [Mn2(C12H8)(CO)6], (II), and [,-1,2(,5)-acetylenedicyclopentadienyl]bis[tricarbonylrhenium(I)], [Re2(C12H8)(CO)6], (IV), are isostructural and isomorphous, and their molecules display inversion symmetry about the mid-point of the ligand C[triple-bond]C bond, with the (CO)3M(C5H4) (M = Mn and Re) moieties adopting a transoid conformation. The molecules in all four compounds form zigzag chains due to the formation of strong attractive I...O [in (I) and (III)] or ,(CO),,(CO) [in (I) and (IV)] interactions along the crystallographic b axis. The zigzag chains are bound to each other by weak intermolecular C,H...O hydrogen bonds for (I) and (III), while for (II) and (IV) the chains are bound to each other by a combination of weak C,H...O hydrogen bonds and ,(Csp2),,(Csp2) stacking interactions between pairs of molecules. The ,(CO),,(CO) contacts in (II) and (IV) between carbonyl groups of neighboring molecules, forming pairwise interactions in a sheared antiparallel dimer motif, are encountered in only 35% of all carbonyl interactions for transition metal,carbonyl compounds. [source] Hydrogen-bonded zigzag chains in 2,2,-dithiodibenzoic acid,1,3-di-4-pyridylpropane (1/1)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2009Li-Li Wang The title 1:1 cocrystal, C14H10O4S2·C13H14N2 or H2L·bpp, has the two components connected by O,H...N hydrogen bonds to generate a one-dimensional zigzag chain running along the crystallographic a direction. These chains are further stacked into a three-dimensional supramolecular network by weak C,H...O and C,H..., contacts. Comparison of the structural differences with previous findings suggests that deprotonated forms, hydrogen-bonding sites and flexible ligand conformations become significant factors that influence the topological arrangement and binding stoichiometry of the resulting cocrystals. [source] Structural effects on the solid-state photodimerization of 2-pyridone derivatives in inclusion compoundsACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2009Marina Telzhensky The structures of six crystalline inclusion compounds between various host molecules and three guest molecules based on the 2-pyridone skeleton are described. The six compounds are 1,1,-biphenyl-2,2,-dicarboxylic acid,2-pyridone (1/2), C14H10O4·2C5H5NO, (I,a), 1,1,-biphenyl-2,2,-dicarboxylic acid,4-methyl-2-pyridone (1/2), C14H10O4·2C6H7NO, (I,c), 1,1,-biphenyl-2,2,-dicarboxylic acid,6-methyl-2-pyridone (1/2), C14H10O4·2C6H7NO, (I,d), 1,1,6,6-tetraphenyl-2,4-hexadiyne-1,6-diol,1-methyl-2-pyridone (1/2), C30H22O2·2C6H7NO, (II,b), 1,1,6,6-tetraphenyl-2,4-hexadiyne-1,6-diol,4-methy-2-pyridone (1/2), C30H22O2·2C6H7NO, (II,c), and 4,4,,4,,-(ethane-1,1,1-triyl)triphenol,6-methyl-2-pyridone,water (1/3/1), C20H18O3·3C6H7NO·H2O, (III,d). In two of the compounds, (I,a) and (I,d), the host molecules lie about crystallographic twofold axes. In two other compounds, (II,b) and (II,c), the host molecules lie across inversion centers. In all cases, the guest molecules are hydrogen bonded to the host molecules through O,H...O=C hydrogen bonds [the range of O...O distances is 2.543,(2),2.843,(2),Å. The pyridone moieties form dimers through N,H...O=C hydrogen bonds in five of the compounds [the range of N...O distances is 2.763,(2),2.968,(2),Å]. In four compounds, (I,a), (I,c), (I,d) and (II,c), the molecules are arranged in extended zigzag chains formed via host,guest hydrogen bonding. In five of the compounds, the guest molecules are arranged in parallel pairs on top of each other, related by inversion centers. However, none of these compounds underwent photodimerization in the solid state upon irradiation. In one of the crystalline compounds, (III,d), the guest molecules are arranged in stacks with one disordered molecule. The unsuccessful dimerization is attributed to the large interatomic distances between the potentially reactive atoms [the range of distances is 4.027,(4),4.865,(4),Å] and to the bad overlap, expressed by the lateral shift between the orbitals of these atoms [the range of the shifts from perfect overlap is 1.727,(4),3.324,(4),Å]. The bad overlap and large distances between potentially photoreactive atoms are attributed to the hydrogen-bonding schemes, because the interactions involved in hydrogen bonding are stronger than those in ,,, interactions. [source] Orthorhombic aluminium oxyfluoride, AlOFACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2009Alexander D. Vasiliev Crystals of the title compound were extracted from the bulk of grown SrAlF5 crystals as unexpected inclusions that were identified as the long sought after aluminium oxyfluoride. The structure of AlOF is built up from tetrahedral and octahedral polyhedra. Each tetrahedron is bisected by a mirror plane, with the Al atom and two vertex anions in the plane. All tetrahedral vertices are positions of competing oxide and fluoride ions and are shared with octahedra. These shared vertices belong to two octahedral edges which join the octahedra to form infinite zigzag chains. The chains are strung along twofold screw axes that run parallel to the unit-cell b axis. The remaining two octahedral vertices are occupied only by fluoride ions. A small deficiency in the occupation of the octahedral Al position was suggested by the refinement. However, the stoichiometry of the compound is AlOF within experimental uncertainty. The Al,F(O) distances are separated into three groups with average values of 1.652,(3) (tetrahedra), 1.800,(2) (octahedra) and 1.894,(2),Å (octahedra). This structure differs widely from the reported tetragonal phase Al1,xO1,3xF1+3x (x = 0.0886) [Kutoglu (1992). Z. Kristallogr.199, 197,201], which consists solely of octahedral structural units. [source] New vanadium(IV) and titanium(IV) oxyfluorotellurates(IV): V2Te2O7F2 and TiTeO3F2ACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2009Jean Paul Laval As part of a continuing study of oxyfluorotellurates(IV), materials likely to present interesting nonlinear optical properties, two new phases, titanium(IV) tellurium(IV) trioxide difluoride, TiTeO3F2, and divanadium(IV) ditellurium(IV) heptaoxide difluoride, V2Te2O7F2, have been characterized and present, respectively, titanium and vanadium in the tetravalent state. The TiTeO3F2 structure is based on linear double rows of TiO3F3 polyhedra sharing vertices. These rows are connected to adjacent rows via two vertices of Te2O5 bipolyhedra. The Te, Ti, one F and two O atoms are on general positions, with one O and F statistically occupying the same site with half-occupancy for each anion. One O and one F occupy sites with .m. symmetry. The V2Te2O7F2 structure consists of zigzag chains of VO4F2 octahedra alternately sharing O,O and F,F edges. These chains are connected via Te2O5 bipolyhedra, forming independent mixed layers. The Te, V, one F and three O atoms are on general positions while one O atom occupies a site of symmetry. In both phases, the electronic lone pair E of the TeIV atom is stereochemically active. A full O/F anionic ordering is observed in V2Te2O7F2, but in TiTeO3F2 one of the six anionic sites is occupied by half oxygen and half fluorine, all the others being strictly ordered. These compounds represent new members of a growing family of oxyfluorotellurates(IV), including the recently characterized members of formula MTeO3F, M being a trivalent cation. As was true for the previous members, they are characterized by an unusually high thermal and chemical stability in relation to the absence of direct Te,F bonds. [source] | |||||||||||||||||||||||||