Infinite Columns Research Articles

Carbamide-containing complexes of lanthanides: competition of hydrogen bonding and polyiodide ion formation

The carbamide complexes of lanthanide polyiodoiodates [Tm(ur)7][I3]3·2I2, [Yb(ur)6][I3]3 and [Lu(ur)6][I3]3 [ur is O=C(NH2)2] have been synthesized and structurally characterized. The structure-forming role of the pentaiodide ions taking part in the formation of extended channels 10–12 Å in diameter with incorporated hepta(carbamide)thulium cations combined to one another into infinite columns due to H-bonding, or the triiodide ions forming lace-like net with isolated hexa(carbamide)ytterbium(iii) or hexa(carbamide) lutetium(iii) cations located in the net holes has been revealed.

4-({[4-Amino-6-(p-bromobenzyl)-5-oxo-4,5-dihydro-1,2,4-triazin-3-yl]sulfanyl}acetyl)-3-phenylsydnone

In the title compound, C20H15BrN6O4S [symstematic name: 4-({[4-amino-6-(p-bromo­benz­yl)-5-oxo-4,5-dihydro-1,2,4-triazin-3-yl]sulfan­yl}acet­yl)-3-phenyl-1,2,3-oxadiazol-3-ium-5-olate], the 4,5-dihydro-1,2,4-triazine ring is essentially planar [maximum deviation = 0.020 (1) Å] and is inclined at dihedral angles of 89.06 (9), 82.21 (8) and 83.98 (8)° with respect to the oxadiazol-3-ium, phenyl and benzene rings. The oxadiazol-3-ium ring forms dihedral angles of 52.71 (9) and 8.77 (9)°, respectively, with the phenyl and benzene rings. In the crystal, the mol­ecules are linked via pairs of inter­molecular N—H⋯O hydrogen bonds, generating R 2 2(10) ring motifs and are further linked via inter­molecular N—H⋯N and weak C—H⋯O hydrogen bonds into infinite columns along [100].

Folding of a Supramolecular Framework Based on a Tetrametallic Clip Driven by π−π Interactions

Supramolecular extended frameworks based on a rotational molecular clip and having the same "primary structure" can exhibit either an unfolded or a folded framework. This process is driven by intramolecular π-π interactions, resulting in the formation of an infinite π-stacked column within the folded supramolecular framework.

5,11,17,23-Tetra-kis(chloro-meth-yl)-25,26,27,28-tetra-propoxycalix[4]arene.

The title calix[4]arene, C44H52Cl4O4, displays the 1,3-alternate conformation with crystallographically imposed twofold symmetry. Four phenolic rings of the calixarene backbone are tilted into the calix cavity, making dihedral angles of 77.42 (2) and 77.71 (2)° with the plane of the four bridging methyl­ene C atoms. Pairs of opposite aromatic rings make dihedral angles of 25.16 (3) and 24.58 (4)° with each other. In the crystal, the calixarene mol­ecules pack with the formation of infinite columns along the b axis. The crystal packing shows a network of C—H⋯Cl contacts, which can be considered as non-classical hydrogen bonds.

Effect of Inclining Strain on the Crystal Lattice along an Extended Series of Lanthanide Hydroxysulfates Ln(OH)SO4(Ln = Pr−Yb, except Pm)

A series of trivalent lanthanide hydroxysulfates, Ln(OH)SO(4), (Ln = Pr through Yb, except radioactive Pm) has been synthesized via hydrothermal methods from Ln(2)(SO(4))(3)·8H(2)O by reaction with aqueous NaOH at 170 °C in Teflon lined Parr steel autoclaves, and were characterized by single crystal X-ray diffraction and FT-IR spectroscopy. Two types of arrangements were found in the solid state. The lighter (Ln = Pr-Nd, Sm-Gd) and heavier lanthanide(III) hydroxysulfates (Tb-Yb) are each isostructural. Both structure types exhibit the monoclinic space group P2(1)/n, but the unit cell content is doubled with two crystallographically distinct LnO(8) polyhedra for the heavier lanthanide compounds. The lighter complexes maintain the coordination number 9, forming a three-dimensional extended lattice. The heavier counterparts exhibit the coordination number 8, and arrange as infinite columns of two crystallographically different LnO(8) polyhedra, while extending along the "c" axis. These columns of LnO(8) polyhedra are surrounded and separated by six columns of sulfate ions, also elongating in the "c" direction. The rigid sulfate entities seem to obstruct the closing in of the lighter LnO(9) polyhedra, and show an inclining degree of torsion into the "ac" layers. The crystal lattice of the lighter 4f complexes can sufficiently withstand the tension buildup, caused by the decreasing Ln(3+) radius, up to Gd(OH)SO(4). The energy profile of this structural arrangement then seems to exceed levels at which this structure type is favorable. The lattice arrangement of the heavier Ln-analogues seems to offer a lower energy profile. This appears to be the preferred arrangement for the heavier lanthanide hydroxysulfates, whose crystal lattice exhibits more flexibility, as the coordination sphere of these analogues is less crowded. The IR absorbance frequencies of the hydroxide ligands correlate as a function of the Ln(3+) ionic radius. This corresponds well with the X-ray single crystal analysis data.

The design of a new concept chromatography column

Active Flow Management is a new separation technique whereby the flow of mobile phase and the injection of sample are introduced to the column in a manner that allows migration according to the principles of the infinite diameter column. A segmented flow outlet fitting allows for the separation of solvent or solute that elutes along the central radial section of the column from that of the sample or solvent that elutes along the wall region of the column. Separation efficiency on the analytical scale is increased by 25% with an increase in sensitivity by as much as 52% compared to conventional separations.

Columnar supramolecular architecture of crystals of 2-(4-Iodophenyl)-1,10-phenanthroline derived from values of intermolecular interaction energy

Using results of X-ray diffraction study supramolecular architecture of crystals of 2-(4-iodophenyl)-1,10-phenanthroline has been analyzed on the basis of quantum-chemical calculations of intermolecular interactions energy. It is demonstrated that these crystals have three levels of organization. Molecules form stacked dimers with the highest binding energy (first level). These dimers represent basic unit of infinite columns stabilized by stacking interactions between dimers (second level). The energy of intermolecular interactions between neighbouring stacked columns is very close. This does not allow to figure out any layers in the crystal. Therefore crystals of this compound have columnar structure with almost isotropic packing of stacked columns (third level).

The combinatorial factor method for investigation of order-disorder in two-dimensional binary alloy

The aim of this study was to investigate order-disorder in the two-dimensional AB alloy to find out whether the number of components, NA and NB, was equal or not. To this end, using the nearest neighbor interactions, first, we applied a two-dimensional lattice which consisted of infinite rows, R and columns, L, so that, RL = NA + NB. For such a model, using the combinatorial factor method, we derived an exact equation for the partition function. Because, the derived partition function was very complicated, the thermodynamic properties of the lattice could not be calculated; however, but these properties could be estimated for the models with a limited number of rows. Our results show that, for models with finite number of rows, for each mole fraction of A in the specific temperature, a phase transition, like Onsager transition, takes place.

Redetermination of bis{(1S,2S,4S,5R)-2-[(R)-hydroxy(6-methoxy-4-quinolyl)methyl]-5-vinylquinuclidinium} sulfate dihydrate

The structure of the title compound, known as quinine sulfate dihydrate, 2C20H25N2O2 +·SO4 2−·2H2O, was previously reported by Mendel [Proc. K. Ned. Akad. Wet. (1955), 58, 132–134], but only the [010] projection was determined. Hence, we have redetermined its crystal structure at 100 K using three-dimensional data. The asymmetric unit consists of a quininium cation, viz. (R)-(6-meth­oxy­quinolinium-4-yl)[(1S,2S,4S,5R)-5-vinyl­quinuclid­in­ium-2-yl]methanol, one half of a sulfate anion and a water mol­ecule. The S atom occupies a special position on a twofold axis. The packing is characterized by infinite columns, consisting of sulfate anions and water mol­ecules, linked through hydrogen bonds along the b axis, and further stabilized by hydrogen bonds to quininium cations. The quininium cations inter­act further through C—H⋯O and C—H⋯π inter­actions.

Supramolecular Systems Based on Ca2+, [Mo3O2S2Cl6(H2O)3]2s-, [Mo3S4Cl6.75Br0.25(H2O)2]3s- and Cucurbit[6]uril

Adducts of cucurbit[6]uril with Ca2+ and trinuclear cluster chloroaquacomplexes (H9O4)2(H7O3)2[(Ca(H2O)5)2(C36H36N24O12)]Cl8·0.67H2O (1) and [(Ca(H2O)5)2(C36H36N24O12)]× [Mo3O2S2Cl6(H2O)3]2·13H2O (2) are obtained and structurally characterized. The structures of both compounds contain polymeric [Ca(H2O)n]22 CB[6]∞ cations that form infinite columns; the space between them is filled with Cls- (1) and [Mo3O2S2Cl6(H2O)3]2s- (2). A new (H7O3)2(H5O2)× [Mo3S4Cl6.25Br0.25(H2O)2](C36H36N24O12)·CH2Cl2·6H2O complex (3) is also obtained and structurally characterized.

Coordination‐Driven Hierarchical Organization of π‐Conjugated Systems: From Molecular to Supramolecular π‐Stacked Assemblies

The reaction of U-shaped, bimetallic, Cu(I) complexes, assembled from a heteroditopic pincer, with cyano-capped pi-conjugated linkers gives a straightforward access to pi-stacked metallocyclophanes in good yields. In these assemblies, the pi-walls have an almost face-to-face arrangement. The versatility of this rational supramolecular synthesis is demonstrated with the use of linkers that have nanoscale lengths (up to 27.7 A), different chemical compositions (oligo(para-phenylenevinylene)s OPVs, oligo(phenylene)s, oligo(phenylethynylene)s), and alternative geometries (linear, angular). Linkers that incorporate an internal pyridyne moiety can also be employed. X-ray diffraction studies revealed that the metallocyclophanes based on linear linkers self-organize into infinite pi-stacked columns in the solid state with intermolecular distances of about 3.6 A. This approach, based on coordination-driven self-assembly, provides a novel and rational strategy for the stacking of extended pi-systems in the solid state.

Synthesis and crystal structure of the mixed-ligand coordination silver polymer [Ag(CH3SO3)(2,3-Et2Pyz)] · H2O

The coordination polymer [Ag(CH3SO3)(2,3-Et2Pyz)] · H2O (2,3-Et2Pyz is diethylpyrazine, C8H12N2) was synthesized and its crystal structure was determined. The crystals are triclinic, space group P\( \bar 1 \), a = 7.212(1)A, b = 8.446(1) A, c = 11.394(1) A, α = 107.58(1)°, β = 100.35(1)°, γ = 99.52(1)°, V = 632.7(1) A3, ρcalc = 1.875 g/cm3, Z = 2. In this structure, pairs of silver atoms are linked by bridging methanesulfonate anions CH3SO3− into dimeric units Ag2(CH3 SO3)2. The distance between the silver atoms in this dimer is 5.16 A.In addition to two oxygen atoms of the CH3SO3 ligands, the Ag+ ion coordinates two nitrogen atoms of the neutral ligand 2,3-Et2Pyz. As a result, polymeric chains [Ag(Et2Pyz)]∞+ are formed along the [100] vector, which are associated in pairs by methanesulfonate anions into infinite columns. Water molecules form H-bonds with oxygen atoms of adjacent CH3SO3− anions.

PYRACMONITE, (NH4)3Fe(SO4)3, A NEW AMMONIUM IRON SULFATE FROM LA FOSSA CRATER, VULCANO, AEOLIAN ISLANDS, ITALY

The new mineral species pyracmonite , ideally (NH 4 ) 3 Fe(SO 4 ) 3 , was found in a medium-temperature (~250°C) active intracrater fumarole at La Fossa crater, Vulcano, Aeolian Islands, Sicily, Italy. It occurs on a pyroclastic breccia as colorless to white prismatic crystals up to 0.2 mm in length, in association with salammoniac and kremersite. The mineral is trigonal, space group R 3 c (no. 161) with a 15.2171(14), c 8.9323(8) A, V 1791.3(3) A 3 and Z = 6. The strongest six reflections in the X-ray powder-diffraction pattern [ d obs in A( I )( hkl )] are: 7.596(100)(110), 3.320(30)(122), 3.371(26)(131), 4.358(23)(121), 2.829(14) (312), and 2.863(8)(321). The empirical formula, based on 12 anions, is [(NH 4 ) 2.74 K 0.23 ] ∑2.97 (Fe 0.94 Al 0.04 ) ∑0.98 S 3.02 O 12 , and the simplified formula (NH 4 ,K) 3 (Fe,Al)(SO 4 ) 3 . The measured density is 2.22(1) g/cm 3 , and D calc is 2.228 g/cm 3 . The mineral is uniaxial, and the average index of refraction index is 1.562(3) (λ= 589 nm). Using single-crystal X-ray-diffraction data, the structure was refined to a final R ( F ) = 0.039 for 1010 independent observed reflections [ I > 2σ( I) ]. The mineral is identical to the synthetic compound (NH 4 ) 3 Fe(SO 4 ) 3 and is isostructural to the high-temperature phase of the synthetic compound (NH 4 ) 3 In(SO 4 ) 3 . Building blocks of the structure are (Fe,Al)O 6 octahedra and SO 4 tetrahedra, which are linked together to form infinite columns [(Fe,Al)(SO 4 ) 3 ] ∞ along [001]. The two independent (Fe,Al)–O distances are 1.959(1) and 1.998(1) A; in the sulfate anion, the S–O distances range from 1.415(2) to 1.485(1) A. The ammonium ions, only partly replaced by K + ions, interact with the oxygen atoms of the sulfate groups via hydrogen bonds.

Phase formation in the Ag2MoO4-CuO-MoO3 system and the crystal structure of the new double molybdate Ag2Cu2(MoO4)3

Subsolidus phase relations in the Ag2MoO4-CuO-MoO3 oxide-salt ternary system were determined. T-x diagram was plotted for the Ag2MoO4-CuMoO4 quasi-binary join. Double molybdate Ag2Cu2(MoO4)3 was found to exist on this join. This compound is a superstructure derived from orthorhombic Li3Fe(MoO4)3. Its structure was solved in terms of a subcell (a = 5.0749(3), b = 11.300(2), c = 18.127(3) A, space group Pnma, Z = 4, R = 0.0678). In the true unit cell, the parameter a is tripled; suggested space group is P212121. A characteristic feature of the Ag2Cu2(MoO4)3 structure is infinite columns (extended along axis a) of face-sharing oxygen octahedra, in which disordered silver atoms are located (Ag(21), Ag(22), and Ag(23)) with various degrees of irregularity of their octahedral coordination and a strong anisotropy of thermal vibrations. Distorted CuO6 octahedra form zigzag ribbons extended in the same direction. MoO4 tetrahedra, which are arranged according to the pseudo-hexagonal law, link the aforementioned major structural elements into a three-dimensional framework. Trigonal-prismatic voids of the framework are occupied by silver atoms Ag (1). Presumably, the disorder of the silver ions in octahedral columns can be responsible for the increased ion conductivity of silver copper molybdate. A partial order of the same ions is the most likely reason for the appearance of superstructure with the tripled unit cell volume.

Structural, electronic, and optical properties of a prototype columnar discotic liquid crystal

Structural, electronic, and optical properties calculated for an isolated infinite column of hexakis-hydroxy-triphenylene (HAT0) molecules are presented. This system is intended as a prototype model of columnar discotic liquid crystals since HAT0 is the first member of the discogenic hexakis-n-alkyloxy-triphenylenes (HATn) series; the single-column approximation can be adopted in view of the peculiar nanoseparation of the columns characteristic of these mesophases. Structural optimization of the system has been performed using Car-Parrinello molecular dynamics techniques. Kohn-Sham orbitals, density of states, and electronic energies have been calculated on the optimized structure of the infinite column and implemented in the quantum expression of the transverse dielectric function. The optical absorption spectrum calculated from the dielectric function has been discussed in comparison to a measured absorption spectrum of HAT5 in columnar discotic liquid crystal phase. Optical absorption spectra of short columns of a few HAT0 molecules arranged as in the infinite column have been calculated using the ZINDO method. These spectra are in good agreement with measured absorption spectra of HAT5 and HAT6 in organic solvents, a fact that supports the proposed columnar arrangement of the discotic molecules in these solvents. We also give an estimate of the electronic transport properties of a small column of HAT0 molecules by calculating with the nonequilibrium Green's function method, the current/voltage characteristic of a model system in which a few HAT0 molecules have been inserted between two gold electrodes under the bias of an external potential.

Estimation of Three-Dimensional Atomic Force Microscope Tip Shape from Atomic Force Microscope Image for Accurate Measurement

We studied methods of estimating three-dimensional (3-D) tip structure using impulse response technique. We have proposed a 3-D tip estimation method using an infinite small diameter standard column as the impulse response technique. The standard column has been made by image processing of a finite-small-diameter-column standard sample by a software elimination technique. We demonstrated how to obtain the 3-D atomic force microscope (AFM) pyramidal tip shape using a commercial pyramidal tip and a 665-nm-diameter-column sample. The estimated tip radii are 10–15 nm in various profiles of the top. The results indicate that the method is effective to estimate a 3-D AFM tip structure in order to obtain an accurate AFM image.

Silver(I)−Ethynide Supramolecular Synthons in the Assembly of π−π Stacked Infinite Columns

In a series of four silver(I) complexes containing nitrate and ethynide ligands attached to different aromatic rings, namely, [Ag2(m-C≡CC6H4C≡C)]·5AgNO3·3H2O (1), 2[(AgC≡C)2-2,3-C4H2S]·10AgNO3 (2), [(AgC≡C)-3-py]·3AgNO3 (3), and 2[(AgC≡C)-2-pyz]·6AgNO3·3H2O (4) (py = pyridine; pyz = pyrazine), intermolecular π−π interaction dominates the assembly of supramolecular synthons Ag4⊂C≡C−R−C≡C⊃Ag4 and R—C≡C⊃Ag4 to give infinite columnar structures exhibiting distinct π−π stacking modes. The decrease in aromaticity of the ring moieties in 1, 3, and 4 is accompanied by weakened π−π stacking, transforming from the parallel face-to-face mode in 1, through a displaced stacked arrangement in 3, to the edge-to-face contact in 4. Replacement of one ethynide moiety of m-phenylenediethynide ligand in 1 by nitrogen coordination sites on the aromatic ring in 3 and 4 was found to have a limited effect on interrupting the whole π−π stacking infinite column.

Tl 4(PO 2NH) 4·H 2O – A commensurately modulated tetrametaphosphimate

Tetrathallium(I) tetra-μ-imidocyclotetraphosphate monohydrate, Tl 4(PO 2NH) 4·H 2O, was obtained by evaporation of combined aqueous solutions of K 4(PO 2NH) 4·4H 2O and TlOOCCH 3 corresponding to the molar ratio of 1:4. The structure determination of Tl 4(PO 2NH) 4·H 2O was performed by single-crystal X-ray diffraction methods. In addition to the basic structure ( P 1 ¯ , no. 2, a = 928.3(2), b = 974.6(2), c = 1018.0(2) pm, α = 74.47(3)°, β = 64.68(3)°, γ = 78.81(3)°, Z = 2), satellite reflections indicate a fourfold superstructure ( A 1 ¯ , a = 928.0(2), b = 3897.1(8), c = 2035.4(4), α = 74.47(3)°, β = 64.68(3)°, γ = 78.81(3)°, Z = 16) that is described by an a × 4 b × 2 c, A-centered supercell which mainly concerns one thallium site of the basic structure. In order to reduce the number of parameters, this superstructure was handled as a commensurate occupancy modulation using the structural description in (3 + 1)-dimensional superspace ( P 1 ¯ ( α β γ ) , q = 0.25 b ∗ + 0.5 c ∗). The crystal structure of Tl 4(PO 2NH) 4·H 2O consists of infinite columns of the cyclic [(PO 2NH) 4] 4− anions (saddle conformation) which are interconnected by four N–H⋯O hydrogen bonds. By coordination to the Tl + ions the [(PO 2NH) 4] 4− columns form a three-dimensional network with channels along [100] wherein the thallium ions that are mainly affected by the modulation are located. The commensurate occupancy modulation of these Tl + ions has been described with a single harmonic wave function. The modulation is verified by 31P NMR spectroscopy. The thermal behavior of Tl 4(PO 2NH) 4·H 2O and the IR data are discussed as well.

Indium strontium hydrogen phosphate SrIn2[PO3(OH)]4: Synthesis and crystal structure

Indium strontium hydrogen nitrate SrIn2[PO3(OH)]4 was synthesized under mild hydrothermal conditions (T = 180 or 200°C) and characterized using IR spectroscopy, chemical analysis, and thermal analysis. A structure model obtained ab initio was refined by the Rietveld method: a= 9.6412(1) A, b = 13.763(1) A, c = 9.3579(1) A, Robs = 0.0183, Rp = 0.0493 (space group B2212, Z = 4). The acentricity of the structure was confirmed by SHG tests (I2ω/I2ω(SiO2) ≈ 2.0). In the SrIn2[PO3(OH)]4 structure, indium atoms reside in distorted InO6 octahedra and form, together with PO3(OH) tetrahedra, a mixed 3D structure {In2[PO3(OH)]4}3∞2− whose voids are occupied by Sr2+ cations (CN = 8). The block-dimer In2(HPO4)10 is the most informative unit of the framework. Blocks are condensed into infinite columns running in the [101] direction. The compound is thermally stable up to 400°C.

Synthesis and Structural Characterization of Butane-1,4-diammonium sulphate

The crystal structure of butane-1,4-diammonium sulphate, C4H14N2 2+ · SO4 2−, exhibits a unique packing arrangement where staggered pairs of butane-1,4-diammonium cations form infinite columns surrounded by sulphate anions. The disordered cation straddles the mirror plane and the asymmetric unit contains one half of the butane-1,4-diammonium cation and one half of the sulphate anion. The bond between C2b and C2a′ is twisted into a gauche conformation as a result of the charge-assisted hydrogen bonding between the doubly charged sulphate anion and the two singly charged ends of the cation chain. An intricate and extensive network of hydrogen bonds is formed within the crystal. Thermal analysis by DSC yielded no evidence of a phase change for the compound. Powder X-ray diffraction analysis yielded very good correlation between the observed and calculated powder pattern obtained from the single crystal data. Crystal data: crystal system, orthorhombic, a = 10.0496 (5) A, b = 9.4186 (4) A, c = 8.8987 (4) A, space group, Pnma, V = 842.29 (7) A3, Z = 4. Synthesis and Structural Characterization of Butane-1,4-diammonium sulphate C. van Blerk and G. J. Kruger Department of Chemistry, University of Johannesburg, 524, Auckland Park, Johannesburg, 2006, Republic of South Africa The structural characteristics of the title compound, which include the crystal structure by single crystal X-ray diffraction, description of the packing arrangement and intermolecular forces from the crystal structure, thermal analysis by differential scanning calorimetry and powder X-ray diffraction studies, are described in this work.