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Supramolecular Structures (supramolecular + structure)
Kinds of Supramolecular Structures Selected AbstractsAnalysis of the Influence of Processing Conditions on the Supramolecular Structure and Antioxidant Distribution in PP-Pipes Using Infrared MicroscopyMACROMOLECULAR MATERIALS & ENGINEERING, Issue 5 2008Robert Brüll Abstract The supramolecular structure in pipe walls of isotactic PP-R is a function of compound composition and processing parameters, which both influence the mechanical properties of the pipes. µFTIR shows a gradient of the crystallinity across the pipe wall, with a lower-crystalline outer layer, and a higher-crystalline core layer. The rate of extrusion has an influence on the thickness of the outer layer. The nucleating effect on the morphological profile throughout the pipe wall can be visualised. µFTIR shows a homogeneous distribution of the primary antioxidant in the pipe wall. Both the spectral crystallinity and the antioxidant concentration distribution are calculated. [source] Supramolecular Structure of Self-assembled Synthetic Zinc-131 -oxo-chlorins Possessing a Primary, Secondary or Tertiary Alcoholic 31 -Hydroxyl Group: Visible Spectroscopic and Molecular Modeling Studies,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2001Shiki Yagai ABSTRACT Zinc-chlorin 3 (see Fig. 2 in text) possessing a tertiary 31 -hydroxyl group and a 13-keto group was synthesized as a model for the antenna chlorophylls of green bacteria. Self-aggregation of 3 in nonpolar organic media was examined and compared to 1 and 2 possessing a primary and secondary 31 -hydroxyl group, respectively. Zinc-chlorin 3 self-aggregated in 1 vol% CH2Cl2,hexane to form oligomers and showed a red-shifted Qy maximum at 704 nm compared to the monomer (648 nm in CH2Cl2). This red-shift is larger than that of 2S (648 , 697 nm) and comparable to that of 2R (648 , 705 nm), but smaller than that of 1 (648 , 740 nm), indicating that while a single 31 -methyl group (prim -OH ,sec -OH) suppressed close and/or higher aggregation, the additional 31 -methyl group (sec -OH ,tert -OH) did not further suppress aggregation. The relative stability of the aggregates was in the order 1 > 2R, 3 > 2S as determined by visible spectral analyses. Molecular modeling calculations on dodecamers of zinc-chlorins 1, 2R and 3 gave similar well-ordered energy-minimized structures, while 1 stacked more tightly than 2R and 3. In contrast, 2S gave a relatively disordered (twisted) structure. The calculated dodecameric structures could explain the visible spectral data of 1,3 in nonpolar organic media. [source] Self-Assembled Ionophores from Isoguanosine: Diffusion NMR Spectroscopy Clarifies Cation's and Anion's Influence on Supramolecular StructureCHEMISTRY - A EUROPEAN JOURNAL, Issue 7 2007Tamar Evan-Salem Abstract Cation-templated self-assembly of the lipophilic isoguanosine (isoG,1) with different monovalent cations (M+=Li+, Na+, K+, NH4+, and Cs+) was studied in solvents of different polarity by using diffusion NMR spectroscopy. Previous studies that did not use diffusion NMR techniques concluded that isoG,1 forms both pentamers (isoG,1)5,M+ and decamers (isoG,1)10,M+ in the presence of alkali-metal cations. The present diffusion NMR studies demonstrate, however, that isoG,1 does not form (isoG,1)5,M+ pentamers. In fact, the diffusion NMR data indicates that both doubly charged decamers of formula (isoG,1)10,2,M+ and singly charged decamers, (isoG,1)10,M+, are formed with lithium, sodium, potassium, and ammonium tetraphenylborate salts (LiB(Ph)4, KB(Ph)4, NaB(Ph)4 and NH4B(Ph)4), depending on the isoG,1:salt stoichiometry of the solution. In the presence of CsB(Ph)4, isoG,1 affords only the singly charged decamers (isoG,1)10,Cs+. By monitoring the diffusion coefficient of the B(Ph)4, ion in the different mixtures of solvents, we also concluded that the anion is more strongly associated to the doubly charged decamers (isoG,1)10,2,M+ than to the singly charged decamers (isoG,1)10,M+. The (isoG,1)10,2,M+ species can, however, exist in solution without the mediation of the anion. This last conclusion was supported by the finding that the doubly charged decamers (isoG,1)10,2,M+ also prevail in 1:1 CD3CN:CDCl3, a solvent mixture in which the B(Ph)4, ion does not interact significantly with the self-assembled complex. These diffusion measurements, which have provided new and improved structural information about these decameric isoG,1 assemblies, demonstrate the utility of combining diffusion NMR techniques with conventional NMR methods in seeking to characterize labile, multicomponent, supramolecular systems in solution, especially those with high symmetry. [source] Triple Hydrogen Bonds Direct Crystal Engineering of Metal-Assembled Complexes: The Effect of a Novel Organic,Inorganic Module on Supramolecular StructureCHEMISTRY - A EUROPEAN JOURNAL, Issue 22 2005Keiichi Adachi Dr. Abstract Novel triply hydrogen bonded suprastructures based on [M(tdpd)2(L)2]2, (H2tdpd=1,4,5,6-tetrahydro-5,6-dioxo-2,3-pyrazinedicarbonitrile, L=solvent) and melamine-analogous cations have been synthesized and characterized. The use of anions containing two AAA sets from [M(tdpd)2(L)2]2, together with cations containing one DDD set (A=hydrogen-bond acceptor, D=hydrogen-bond donor) leads to the formation of complementary triply hydrogen bonded modules in the solid state. In all cases, the building module is further extended via additional hydrogen-bonding interactions to produce a tape, and tapes are assembled into sheets. These results show that a hydrogen-bonded module consisting of different kinds of building blocks, one of which is a metal complex that includes hydrogen-bond acceptor sites and the other is a hydrogen-bond donor molecule, will be attractive for constructing metal-containing supramolecular systems by the self-assembly technique. [source] Supramolecular Structures Generated by Spherical Polyelectrolyte Brushes and their Application in CatalysisMACROMOLECULAR RAPID COMMUNICATIONS, Issue 9-10 2009Yan Lu Abstract We survey recent studies on composite particles made from spherical polyelectrolyte brushes (SPB) and catalytically active nanoparticles or enzymes. SPB consist of a solid core (diameter: ca. 100 nm) onto which long chains of anionic or cationic polyelectrolyte (PE) are densely grafted ("PE brush"). Immersed in water the PE layer affixed to the colloidal core will swell due to the enormous osmotic pressure of the confined counterions ("osmotic brush"). This confinement of the counterions can be used to generate metal nanoparticles on the surface of the SPB. Moreover, enzymes can be immobilized within the PE layer. In both cases, the resulting composite particles are stable against coagulation and can be easily handled and filtered off. The catalytic activity of both systems is largely preserved in case of the enzymes, in case of the metal nanoparticles it is even enhanced. Thus, the SPB present an excellent carrier system for applications in catalysis. [source] Facile Route to Supramolecular Structures: Self-Assembly of Dendrimers and Naphthalene Dicarboxylic AcidsCHEMISTRY - A EUROPEAN JOURNAL, Issue 23 2008Franziska Gröhn Dr. Cylinders and spheres can be formed by simple self-assembly of cationic dendrimers and oppositely charged small divalent organic ions in methanol (see graphic). The counterion not only controls the morphology of the nanosized assembly, but also provides functionality, such as fluorescence. The concept may lead to versatile functional supramolecular architectures. [source] Supramolecular structure of 1H -pyrazoles in the solid state: a crystallographic and ab initio studyACTA CRYSTALLOGRAPHICA SECTION B, Issue 6 2000Concepción Foces-Foces The secondary structure of 1H -unsubstituted pyrazole derivatives bearing only one hydrogen donor group and one or more acceptor groups has been analyzed in terms of some descriptors representing the substituents at C3 and C5. The substituent at C4 appears to affect mainly the tertiary or quaternary structure of these compounds. The proposed semi-quantitative model, which explains most hydrogen-bonded motifs as a combination of the effects of substituents at C3 and C5, has also been examined as a function of the steric and polarizability effects of these substituents represented by molar refractivity. The model also applies to other five-membered rings (1,2,4-triazoles, 1,2,4-diazaphospholes and 1,2,4-diazaarsoles). Furthermore, ab initio calculations at RHF/6-31G* have been performed to discover the relative stability of three of the four hydrogen-bond patterns displayed by several symmetrical pyrazoles (dimers, trimers, tetramers). The fourth motif, catemers, has only been discussed geometrically. [source] Crystallographic report: Supramolecular structure of 2-aminonicotinatodimethylthallium(III), [TlMe2(2anic)]nAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 6 2004Monica Toma Abstract The title compound displays an overall two-dimensional supramolecular arrangement comprising [TlMe2(2anic)] units linked by TlN bonds and weak Tl···O interactions. Copyright © 2004 John Wiley & Sons, Ltd. [source] Synthesis, Crystal Structure and Characterisation of a Novel Chiral Mixed-Valence Vanadium Oxide Hybrid, [V5O11(dien)3]EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 15 2005Ming-Lai Fu Abstract The novel chiral mixed-valence vanadium oxide hybrid [V5O11(dien)3] (1) (dien = NH2C2H4NHC2H4NH2) has been synthesised by a hydrothermal reaction of V2O5 and dien in aqueous solution and characterised by elemental analysis, IR spectroscopy, TG-DSC analysis, magnetism, EPR spectroscopy, single-crystal X-ray diffraction and powder XRD. The X-ray diffraction analysis revealed that the structure of 1 can be regarded as being constructed from two [VVO4]3, groups bicapping three [VIVO(dien)]2+ units to form a discrete asymmetric pentanuclear vanadium complex with the dien ligands coordinating directly to the vanadium(IV) centres. Compound 1 exhibits an interesting tube-like 3D supramolecular structure due to abundant hydrogen-bonding interactions between the oxygen atoms of the inorganic backbone and the hydrogen atoms of the dien ligands from adjacent molecules. The variable-temperature magnetic susceptibility data of 1 suggest a weak ferromagnetic interaction among V4+ ions in the cluster. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Casein phosphopeptide promotion of calcium uptake in HT-29 cells , relationship between biological activity and supramolecular structureFEBS JOURNAL, Issue 19 2007Claudia Gravaghi Casein phosphopeptides (CPPs) form aggregated complexes with calcium phosphate and induce Ca2+ influx into HT-29 cells that have been shown to be differentiated in culture. The relationship between the aggregation of CPPs assessed by laser light scattering and their biological effect was studied using the CPPs ,-CN(1,25)4P and ,s1 -CN(59,79)5P, the commercial mixture CPP DMV, the ,cluster sequence' pentapeptide, typical of CPPs, and dephosphorylated ,-CN(1,25)4P, [,-CN(1,25)0P]. The biological effect was found to be: (a) maximal with ,-CN(1,25)4P and null with the ,cluster sequence'; (b) independent of the presence of inorganic phosphate; and (c) maximal at 4 mmol·L,1 Ca2+. The aggregation of CPP had the following features: (a) rapid occurrence; (b) maximal aggregation by ,-CN(1,25)4P with aggregates of 60 nm hydrodynamic radius; (c) need for the concomitant presence of Ca2+ and CPP for optimal aggregation; (d) lower aggregation in Ca2+ -free Krebs/Ringer/Hepes; (e) formation of bigger aggregates (150 nm radius) with ,-CN(1,25)0P. With both ,-CN(1,25)4P and CPP DMV, the maximum biological activity and degree of aggregation were reached at 4 mmol·L,1 Ca2+. [source] Tuning the Amphiphilicity of Building Blocks: Controlled Self-Assembly and Disassembly for Functional Supramolecular Materials,ADVANCED MATERIALS, Issue 28 2009Yapei Wang Abstract Amphiphilicity is one of the molecular bases for self-assembly. By tuning the amphiphilicity of building blocks, controllable self-assembly can be realized. This article reviews different routes for tuning amphiphilicity and discusses different possibilities for self-assembly and disassembly in a controlled manner. In general, this includes irreversible and reversible routes. The irreversible routes concern irreversible reactions taking place on the building blocks and changing their molecular amphiphilicity. The building blocks are then able to self-assemble to form different supramolecular structures, but cannot remain stable upon loss of amphiphilicity. Compared to the irreversible routes, the reversible routes are more attractive due to the good control over the assembly and disassembly of the supramolecular structure formed via tuning of the amphiphilicity. These routes involve reversible chemical reactions and supramolecular approaches, and different external stimuli can be used to trigger reversible changes of amphiphilicity, including light, redox, pH, and enzymes. It is anticipated that this line of research can lead to the fabrication of new functional supramolecular assemblies and materials. [source] New Cyclic Olefin Copolymer for the Preparation of Thermally Responsive Luminescent FilmsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 9 2009Filippo Donati Abstract Polymer films with optical properties as indicators to thermal stress were obtained through the controlled dispersion of moderate amounts (,0.1 wt.-%) of the 4,4,-bis(2-benzoxazolyl)stilbene (BBS) dye into a new semicrystalline ethylene-norbornene (E - co - N, N content of 15.3 mol.-%) copolymer characterized by a glass transition temperature (Tg) of about 64,°C. All the pristine films showed optical characteristics coming from noninteracting BBS chromophores. In contrast permanent optical changes were detected after film annealing at a T,,,Tg due to the variation of the BBS supramolecular structure. The easy modulation of the optical features of polymer films by thermal perturbations suggests applications as threshold temperature visual indicators in thermoplastic materials. [source] Donor-Embedded Polybinaphthalenes for Nonlinear Optical Applications: Influence of the Incorporation of a Double BondMACROMOLECULAR RAPID COMMUNICATIONS, Issue 11 2005Guy Koeckelberghs Abstract Summary: In this paper two new donor-embedded polybinaphthalenes prepared by the Heck reaction are presented. By introducing a double bond in the polymer backbone, the supramolecular structure was altered in comparison with polymers without the double bond. Comparison between the CD/UV-Vis spectra of polymers, with and without the double bond (previously synthesized in our laboratory) proved this change in a supramolecular structure. The double bonds also allow crosslinking upon heat treatment. NLO experiments demonstrated a more stable nonlinearity over time depending on the degree of crosslinking. [source] Model of the influence of energetic disorder on inter-chain charge carrier mobility in poly[2-methoxy-5-(2,-ethylhexyloxy)- p -phenylene vinylene]POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 3 2009Petr Toman Abstract The theoretical model of the inter-chain charge carrier mobility in poly[2-methoxy-5-(2,-ethylhexyloxy)- p -phenylene vinylene] (MEH,PPV) doped with polar additive is put forward. The polymer chain states of a charge carrier were calculated by means of diagonalization of a tight-binding Hamiltonian, which includes disorder in both the local energies and transfer integrals. Consequently, the inter-chain charge carrier transport is taking place on a spatially and energetically disordered medium. Because it is believed that the additive does not significantly influence the polymer supramolecular structure, the polymer conformations were simplified as much as possible. On the other hand, the energetic disorder is rigorously described. The transfer rates between the polymer chains were determined using the quasi-classical Marcus theory. The model considered the following steps of the charge carrier transport: the charge carrier hops to a given polymer chain. Then, the charge carrier thermalizes to the Boltzmann distribution over all its possible states on this chain. After that, the charge carrier hops to any possible state on one of the four nearest neighboring chains. The results showed that the inter-chain charge carrier mobility is very strongly dependent on the degree of the energetic disorder. If the energetic disorder is doubled from 0.09 to 0.18,eV, the mobility decreases by two or three orders of magnitude. Copyright © 2008 John Wiley & Sons, Ltd. [source] Isomeric N -(iodophenyl)nitrobenzamides form different three-dimensional framework structuresACTA CRYSTALLOGRAPHICA SECTION B, Issue 5 2006James L. Wardell The isomeric N -(iodophenyl)nitrobenzamides, C13H9IN2O3, all form different three-dimensional framework structures. Molecules of N -(2-iodophenyl)-3-nitrobenzamide (II) are linked by a combination of N,H,O and C,H,O hydrogen bonds and a two-centre iodo,carbonyl interaction. The supramolecular structure of N -(2-iodophenyl)-4-nitrobenzamide (III) is built from one N,H,O and two C,H,O hydrogen bonds, but short I,O contacts are absent from the structure. In N -(3-iodophenyl)-2-nitrobenzamide (IV), which crystallizes with Z, = 2 in space group P21, the structure contains two N,H,O hydrogen bonds, four C,H,O hydrogen bonds, two two-centre iodo,nitro interactions and an aromatic ,,, stacking interaction. The structure of N -(3-iodophenyl)-3-nitrobenzamide (V) contains one N,H,O hydrogen bond and three C,H,O hydrogen bonds, together with a two-centre iodo,nitro interaction and an aromatic ,,, stacking interaction, while in N -(3-iodophenyl)-4-nitrobenzamide (VI), the combination of one N,H,O hydrogen bond and two C,H,O hydrogen bonds is augmented not only by a two-centre iodo,nitro interaction and an aromatic ,,, stacking interaction, but also by a dipolar carbonyl,carbonyl interaction. In the supramolecular structure of N -(4-iodophenyl)-4-nitrobenzamide (IX), which crystallizes with Z, = 2 in space group , there are two N,H,O hydrogen bonds, four C,H,O hydrogen bonds and two three-centre iodo,nitro interactions. [source] [,3 - cis - N -(2-Aminoethyl)- N,-(2-carboxylatophenyl)oxamidato(3,)]bis(2,2,-diamino-4,4,-bi-1,3-thiazole)tetracopper(II) bis(2,4,6-trinitrophenolate)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2010Xiao-Wen Li The title complex, [Cu4(C11H10N3O4)2(C6H6N4S2)2](C6H2N3O7)2, consists of a circular tetracopper(II) cation with an embedded inversion centre and two uncoordinated picrate (2,4,6-trinitrophenolate) anions. The CuII cations at the inner sites of N -(2-aminoethyl)- N,-(2-carboxylatophenyl)oxamidate(3,) (oxbe) have square-planar environments and those at the outer sites are in square-pyramidal geometries. The separations of pairs of CuII cations bridged by cis -oxamide and carboxylate groups are 5.2217,(5) and 5.2871,(5),Å, respectively. The tetracopper(II) cations and picrate anions are connected by N,H...O hydrogen bonds into a two-dimensional network parallel to the (010) plane, and these two-dimensional networks are assembled by two types of ,,, stacking interactions into a three-dimensional supramolecular structure. [source] Propane-1,3-diaminium tetrachloridozincate(II) 18-crown-6 clathrateACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2010Min Min Zhao The reaction of propane-1,3-diamine hydrochloride, 18-crown-6 and zinc(II) chloride in methanol solution yields the title complex salt [systematic name: propane-1,3-diaminium tetrachloridozincate(II),1,4,7,10,13,16-hexaoxacyclooctadecane (1/1)], (C3H12N2)[ZnCl4]·C12H24O6, with an unusual supramolecular structure. The diprotonated propane-1,3-diaminium cation forms an unexpected 1:1 supramolecular rotator,stator complex with the crown ether, viz. [C3H12N2(18-crown-6)]2+, in which one of the ,NH3+ substituents nests in the crown and interacts through N,H...O hydrogen bonding. The other ,NH3+ group interacts with the [ZnCl4]2, anion via N,H...Cl hydrogen bonding, forming cation,crown,anion ribbons parallel to [010]. [source] Two-dimensional networks in 2-methylanilinium picrate and 2,5-dichloroanilinium picrateACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2010Gao-Xiang Meng Both the title molecular adducts of 2-methylaniline or 2,5-dichloroaniline with picric acid are 1:1 organic salts, namely 2-methylanilinium picrate, C7H10N+·C6H2N3O7,, (I), and 2,5-dichloroanilinium picrate, C6H6Cl2N+·C6H2N3O7,, (II). In both structures, the phenoxide O atoms accept two N,H hydrogen bonds in a bifurcated acceptor fashion, which link the component ions by N,H...O hydrogen bonds into continuous two-dimensional zigzag layers, running parallel to the (100) plane in (I) and the (010) plane in (II). A ,,, interaction is observed between symmetry-related anilinium cations in (I), while in (II), Cl...Onitro and Cl...Cl interactions are observed. This study indicates that a substitution on aniline can exert a pivotal influence on the construction of its supramolecular structure. [source] A three-dimensional supramolecular vanadium hydroxylamide complex: poly[di-,2 -aqua-bis(hydroxylamido)-,3 -malonato-oxidosodiumvanadium(V)]ACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2009Qi-Ying Zhang The crystal structure of the title compound, [NaV(C3H2O4)(NH2O)2O(H2O)2], is built up of NaO6 and VO5N2 polyhedra connected through malonate bridges. The NaO6 octahedra are linked by edge sharing in the equatorial plane to form one-dimensional infinite chains. These chains are linked together by the malonate bridges to form two-dimensional layers. The distorted VO5N2 pentagonal bipyramid is grafted on to the layer by a malonate carboxylate O atom. Adjacent layers are connected through O,H...O and N,H...O hydrogen bonds to build up a three-dimensional supramolecular structure. [source] 4,4,-Methylenediphenol,4,4,-bipyridine (2/3): decarboxylation of 5,5,-methylenedisalicylic acid under hydrothermal conditionsACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2009Zhi-Hui Zhang Reaction of 5,5,-methylenedisalicylic acid (5,5,-H4mdsa) with 4,4,-bipyridine (4,4,-bipy) and manganese(II) acetate under hydrothermal conditions led to the unexpected 2:3 binary cocrystal 4,4,-methylenediphenol,4,4,-bipyridine (2/3), C13H12O2·1.5C10H8N2 or (4,4,-H2dhdp)(4,4,-bipy)1.5, which is formed with a concomitant decarboxylation. The asymmetric unit contains one and a half 4,4,-bipy molecules, one of which straddles a centre of inversion, and one 4,4,-H2dhdp molecule. O,H...N interactions between the hydroxy and pyridyl groups lead to a discrete ribbon motif with an unusual 2:3 stoichiometric ratio of strong hydrogen-bonding donors and acceptors. One of the pyridyl N-atom donors is not involved in hydrogen-bond formation. Additional weak C,H...O interactions between 4,4,-bipy and 4,4,-H2dhdp molecules complete a two-dimensional bilayer supramolecular structure. [source] Two polymeric nickel(II) complexes with aromatic benzene-1,2,4,5-tetracarboxylate and pyridine-2,5-dicarboxylate linkersACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2009Ana María Atria (,-Benzene-1,2,4,5-tetracarboxylato-,2O1:O4)bis[aquabis(2,2-methylpropane-1,3-diamine-,2N,N,)nickel(II)] methanol disolvate tetrahydrate, [Ni2(C10H2O8)(C5H14N2)4(H2O)2]·2CH4O·4H2O, (I), is dinuclear, with elemental units built up around an inversion centre halving the benzene-1,2,4,5-tetracarboxylate (btc) anion, which bridges two symmetry-related NiII cations. The octahedral Ni polyhedron is completed by two chelating 2,2-methylpropane-1,3-diamine (dmpda) groups and a terminal aqua ligand. Two methanol and four water solvent molecules are involved in a number of N,H...O and O,H...O hydrogen bonds which define a strongly bound two-dimensional supramolecular structure. The structure of catena -poly[[[bis(2,2-methylpropane-1,3-diamine-,2N,N,)nickel(II)]-,-pyridine-2,5-dicarboxylato-,3O5:N,O2 -[(2,2-methylpropane-1,3-diamine-,2N,N,)nickel(II)]-,-pyridine-2,5-dicarboxylato-,3N,O2:O5] octahydrate], {[Ni2(C7H3NO4)2(C5H14N2)3]·8H2O}n, (II), is polymeric, forming twisted chains around three independent Ni centres, two of which lie on inversion centres and the third in a general position. There are three chelating dmpda ligands (one disordered over two equally populated positions), which are each attached to a different cation, and two pyridine-2,5-dicarboxylate (pdc) anions, both chelating the Ni centre in general positions through an ,O,C,C,N, loop, while acting as bridges to the remaining two centrosymmetric Ni atoms. There are, in addition, eight noncoordinated water molecules in the structure, some of which are disordered. [source] Trinitratobis{N,-[1-(2-pyridyl)ethylidene]isonicotinohydrazide}cerium(III): a three-dimensional cerium,organic supramolecular structureACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2009Ying-Ying Zhang The CeIII ion in the title complex, [Ce(NO3)3(C13H12N4O)2], is 12-coordinated by six chelating nitrate O atoms and six donors (2 O and 4 N atoms) of two N,-[1-(2-pyridyl)ethylidene]isonicotinohydrazide ligands, exhibiting a bicapped pentagonal-antiprism-type coordination geometry. The title complex possesses C2 point symmetry and is located on a twofold crystallographic axis. Each molecule is linked with four surrounding molecules by four N,H...N hydrogen bonds, resulting in an extended two-dimensional layer parallel to the ab plane, while ,,, interactions between pyridine rings from neighboring complex molecules connect the two-dimensional layers into a three-dimensional cerium,organic supramolecular structure. [source] Self-inclusion structure of 5,11,17,23-tetrakis(azidomethyl)-25,26,27,28-tetrahydroxycalix[4]arene, and 5,11,17,23-tetra- tert -butyl-25,27-bis(chloroacetoxy)-26,28-bis(2-pyridylmethoxy)calix[4]areneACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2009Mei Zhao In the structures of the two title calix[4]arene derivatives, C32H28N12O4, (I), and C60H68Cl2N2O6, (II), compound (I) adopts an open-cone conformation in which there are four intramolecular O,H...O hydrogen bonds, while compound (II) adopts a distorted chalice conformation where the two pendant pyridyl rings, one of which is disordered, are almost mutually perpendicular, with an interplanar angle of 79.2,(2) or 71.4,(2)°. The dihedral angles between the virtual plane defined by the four bridging methylene C atoms and the phenol rings are 120.27,(7), 124.03,(6), 120.14,(8) and 128.25,(7)° for (I), and 95.99,(8), 135.93,(7), 97.21,(8) and 126.10,(8)° for (II). In the supramolecular structure of (I), pairs of molecules associate by self-inclusion, where one azide group of the molecule is inserted into the cavity of the inversion-related molecule, and the association is stabilized by weak intermolecular C,H...N hydrogen bonds and ,(N3),,(aromatic) interactions. The molecular pairs are linked into a two-dimensional network by a combination of weak intermolecular C,H...N contacts. Each network is further connected to its neighbor to produce a three-dimensional framework via intersheet C,H...N hydrogen bonds. In the crystal packing of (II), the molecular components are linked into an infinite chain by intermolecular C,H...O hydrogen bonds. This study demonstrates the ability of calix[4]arene derivatives to form self-inclusion structures. [source] trans -Diaquabis(nicotinamide-,N)bis(salicylato-,O)cobalt(II)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2008The title compound, [Co(C7H5O3)2(C6H6N2O)2(H2O)2], forms a three-dimensional hydrogen-bonded supramolecular structure. The CoII ion is in an octahedral coordination environment comprising two pyridyl N atoms, two carboxylate O atoms and two O atoms from water molecules. Intermolecular N,H...O and O,H...O hydrogen bonds produce R22(8), R22(12) and R22(14) rings, which lead to two-dimensional chains. An extensive three-dimensional supramolecular network of C,H...O, N,H...O and O,H...O hydrogen bonds and C,H..., interactions is responsible for crystal structure stabilization. This study is an example of the construction of a supramolecular assembly based on hydrogen bonds in mixed-ligand metal complexes. [source] An unusual chain cadmium(II) coordination polymer: catena -poly[[(2,2,-bipyridyl-,2N,N,)cadmium(II)]-di-,-chlorido-[(2,2,-bipyridyl-,2N,N,)cadmium(II)]-di-,-thiocyanato-,2N:S;,2S:N]ACTA CRYSTALLOGRAPHICA SECTION C, Issue 12 2007Min Chen The title complex, [CdCl(NCS)(C10H8N2)]n, represents an unusual CdII coordination polymer constructed by two types of anionic bridges and 2,2,-bipyridyl (bipy) terminal ligands. These two types of bridges are arranged around inversion centers. The distorted octahedral coordination of the CdII center is provided by two chloride ions, one N- and one S-donor atom from two thiocyanate ions, and a pair of N atoms from the chelating bipy ligand. Interestingly, adjacent CdII ions are interconnected alternately by paired chloride [Cd...Cd = 3.916,(1),Å] and thiocyanate bridges [Cd...Cd = 5.936,(1),Å] to generate an infinite one-dimensional coordination chain. Furthermore, weak interchain C,H...S interactions between the bipy components and thiocyanate ions lead to the formation of a layered supramolecular structure. [source] A new coordination mode of 6-methylnicotinic acid in trans -tetraaquabis(6-methylpyridine-3-carboxylato-,O)cobalt(II) tetrahydrateACTA CRYSTALLOGRAPHICA SECTION C, Issue 12 2007Boris-Marko Kukovec The title compound, [Co(C7H6NO2)2(H2O)4]·4H2O, contains a CoII ion lying on a crystallographic inversion centre. The CoII ion is octahedrally coordinated by two 6-methylpyridine-3-carboxylate ligands in axial positions [Co,O = 2.0621,(9),Å] and by four water molecules in the equatorial plane [Co,O = 2.1169,(9) and 2.1223,(11),Å]. There are also four uncoordinated water molecules. The 6-methylpyridine-3-carboxylate ligands are bound to the CoII ion in a monodentate manner through a carboxylate O atom. There is one strong intramolecular O,H...O hydrogen bond, and six strong intermolecular hydrogen bonds of type O,H...O and one of type O,H...N in the packing, resulting in a complex three-dimensional supramolecular structure. [source] Three-dimensional supramolecular structures in (E,E)- N,N,-bis(4-nitrobenzylidene)butane-1,4-diamine and (E,E)- N,N,-bis(4-nitrobenzylidene)hexane-1,6-diamineACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2006John N. Low In both (E,E)- N,N,-bis(4-nitrobenzylidene)butane-1,4-diamine, C18H18N4O4, (III), and (E,E)- N,N,-bis(4-nitrobenzylidene)hexane-1,6-diamine, C20H22N4O4, (IV), the molecules lie across centres of inversion in space groups P and P21/c, respectively. In (III), the three-dimensional supramolecular structure is built from ,-stacked chains of edge-fused R22(30) rings, while in (IV), chains of edge-fused R22(38) rings are linked by dipolar nitro,nitro interactions. [source] Synthesis, structural characterization and cytotoxic activity of diorganotin(IV) complexes of N -(5-halosalicylidene)tryptophaneAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 1 2009Laijin Tian Abstract Four new diorganotin(IV) complexes of N -(5-halosalicylidene)tryptophane, R2Sn[5-X-2-OC6H3CHNCH(CH2Ind)COO] [Ind = 3-indolyl; R, X = Et, Cl (1); Et, Br(2); n -Bu, Cl (3); n -Bu, Br (4)], were synthesized and characterized by elemental analysis, IR and NMR (1H, 13C and 119Sn) spectra. The crystal structures of complexes 1,3 were determined by X-ray single crystal diffraction and showed that the tin atoms are in a distorted trigonal bipyramidal geometry and form five- and six-membered chelate rings with the tridentate ligand. Intermolecular weak interactions in 1,3 link molecules, respectively, into a two-dimensional array, a one-dimensional infinite chain and a one-dimensional double-chain supramolecular structure. Bioassay results of the compounds indicated that the dibutyltin complexes 3 and 4 have potent in vitro cytotoxic activity against two human tumor cell lines, CoLo205 and Bcap37, while the diethyltin complexes 1 and 2 display weak cytotoxic activity. Copyright © 2008 John Wiley & Sons, Ltd. [source] A capped trigonal prismatic cadmium complex with tetra- and tridentate ligands: bis(triethanolamine)-,3N,O,O,;,4N,O,O,,O,,-cadmium(II) squarate monohydrateACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2004brahim Uçar In the crystal structure of the title compound, [Cd(C6H15NO3)2](C4O4)·H2O, a supramolecular structure is observed. The asymmetric unit consists of one unit of the cationic Cd complex, one water molecule and two half-squarate anions, each sitting on a crystallographic inversion center. The different coordinations of the two triethanolamine (TEA) ligands results in an unusual example of coordination number seven for the CdII ion. Both TEA ligands coordinate to the CdII ion, forming a distorted monocapped trigonal prismatic geometry with approximate C2v symmetry. One of the TEA ligands acts as an N,O,O,-tridentate ligand, whereas the other behaves as an N,O,O,,O,,-tetradentate donor. The anions and cations are linked to one another by hydrogen bonds between hydroxy H atoms of the TEA ligands and squarate O atoms. The crystal structure is stabilized by O,H,O hydrogen bonds between the unligated water molecule and a squarate O atom, together with a weak ,,ring interaction between the ethylene group of a TEA ligand and a squarate anion. [source] The isothiocyanate complex of triphenylborane forms an unusual coordination polymer with [K(18-crown-6)]+, both in the solid state and in solutionACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2003Orde Q. Munro The title salt, (1,4,7,10,13,16-hexaoxacyclooctadecane-,6O)[(isothiocyanato)triphenylborato-,S]potassium(I), [K(C19H15BNS)(C12H24O6)] or [K(SCNBPh3)(18-crown-6)], where 18-crown-6 is 1,4,7,10,13,16-hexaoxacyclooctadecane and [SCNBPh3], is the (isothiocyanato)triphenylborate anion, exhibits a supramolecular structure that is best described as a helical coordination polymer or molecular screw. This unusual supramolecular structure is based on a framework in which the SCN, ion bridges the chelated K+ ion and the B atom of BPh3 in a ,2 fashion. The X-ray crystal structure of the title salt has been determined at 100,(1) and 293,(2),K. The K+ ion exhibits axial ligation by the S atom of the [SCNBPh3], anion, with a K,S distance of 3.2617,(17),Å (100,K). The trans -axial ligand is an unexpected ,2 -bound C=C bond of a phenyl group (meta - and para -C atoms) that belongs to the BPh3 moiety of a neighboring molecule. The K,C bond distances span the range 3.099,(3),3.310,(3),Å (100,K) and are apparently retained in CDCl3 solution (as evidenced by 13C NMR spectroscopy). By virtue of the latter interaction, the supramolecular structure is a helical coordination polymer, with the helix axis parallel to the b axis of the unit cell. IR spectroscopy and semi-empirical molecular orbital (AM1) calculations have been used to investigate further the electronic structure of the [SCNBPh3], ion. [source] | |||||||||||||||||||||||||||||||||||||