Synthesis,physical properties,and structure of TIPS-difuranoacenes

The synthesis, physical properties, and structure of triisopropylsilylethynyltetracenodifuran (2) and pentacenodifuran (3) derivatives were reported. There showed high stability in solution in the dark, yet decomposed under light. Single crystal of pentacenodifuran was analyzed by X-ray diffraction analysis, and showed one dimensional packing array along the c-axis. The molecules were stacked with a 3.30 Å interlayer distance. The crystals exhibited a high thermal stability under an ambient condition.     

Synthesis and physical properties of layered silicates/polyurethane nanocomposites

Samples of polyurethane nanocomposites were synthesized using diphenylmethane diisocyanate, poly(ε‐caprolactone) diol, di(ethylene glycol), and a clay functionalized by hydroxyl groups. The inorganic content in the hybrids was 2 wt %, 4 wt %, and 8 wt %. The X‐ray analysis showed that exfoliation occurred for clay content equal to 2% (w/w), whereas for higher contents, the inorganic phase rearranges in an intercalated structure. FTIR analysis suggested that the degree of hydrogen bonding in the hard segments was greatly reduced because of the amount of silicate layers and their dispersion. The dynamic‐mechanical analysis showed that the presence of clay lamellae extends very much the temperature range before the hard domain transition, causing the loss of mechanical consistency of the samples. It is less than 100 °C for the pure polymer, and increases up to 200 °C for the nanocomposites. The permeability of water vapor decreases linearly with inorganic content up to 4% of inorganic phase, and levels off at higher concentrations. The permeability behavior, at low activities, is largely dominated by the diffusion phenomenon. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2454–2467, 2005     

Synthesis,structure, physical properties,and electronic structure of KGaSe2

The ternary gallium selenide KGaSe₂ has been synthesized by solid-state reactions and good quality crystal has been obtained. KGaSe₂ crystallizes in the monoclinic space group C2/c with cell dimensions of a = 10.878(2) Å, b = 10.872(2) Å, c = 15.380(3) Å, and β = 100.18(3)°. In the structure, adamantane like [Ga₄Se₁₀]⁸⁻ units are connected by common corners forming two-dimensional [GaSe₂]⁻ layers which are separated by K⁺ cations. KGaSe₂ exhibits congruent-melting behavior at around 965 °C. It is transparent in the range of 0.47–20.0 μm and has a band gap of 2.60(2) eV. From a band structure calculation, KGaSe₂ is a direct-gap semiconductor. The band gap is mainly determined by the [GaSe₂]⁻ layer.     

Synthesis, structure, and dynamic properties of hybrid organic-inorganic rotaxanes

The synthesis and characterization of a series of hybrid organic-inorganic [2]rotaxanes is described. The ring components are heterometallic octa- ([Cr(7)MF(8)(O(2)C(t)Bu)(16)]; M = Co, Ni, Fe, Mn, Cu, Zn, and Cd) nuclear cages in which the metal centers are bridged by fluoride and pivalate ((t)BuCO(2)(-)) anions; the thread components feature dialkylammonium units that template the formation of the heterometallic rings about the axle to form the interlocked structures in up to 92% yield in conventional macrocyclization or one-pot 'stoppering-plus-macrocyclization' strategies. The presence in the reaction mixture of additives (secondary or tertiary amines or quaternary ammonium salts), and the nature of the stoppering groups (3,5-(t)Bu(2)C(6)H(3)CO(2)- or (t)BuCONH-), can have a significant effect on the rotaxane yield. The X-ray crystal structures of 11 different [2]rotaxanes, a pseudorotaxane, and a two-station molecular shuttle show two distinct types of intercomponent hydrogen bond motifs between the ammonium groups of the organic thread and the fluoride groups of the inorganic ring. The different hydrogen bonding motifs account for the very different rates of dynamics observed for the heterometallic ring on the thread (shuttling slow; rotation fast).     

Polymer-filled nanoporous silica aerogels as hosts for highly stable solid-state dye lasers

New hybrid solid-state dye laser materials based on highly porous silica aerogels have been synthesized. The open porous network of the aerogel was saturated with laser dyes dissolved in appropriate organic monomers, and polymerization took place inside the silica structure. The resulting polymer-filled nanoporous aerogel (PFNPA) was cast in a cylindrical shape, forming monoliths that were used as gain media in solid-state dye lasers. When the PFNPA incorporated pyrromethene dyes, highly photostable laser emission with good lasing efficiency was obtained. Under the demanding conditions of tightly focused transversal pumping with 532 nm, 5 mJ pulses at 10 Hz repetition rate, the commercial dye Pyrromethene 567 exhibited laser action with only a 10% drop in the laser output after 10(6) pump pulses in the same position of the sample.     

Synthesis, crystal structure and some physical properties of RuZn3

The crystal structure, phase relations and some physical properties of the binary zinc-rich phase RuZn3 are reported. The title compound is accessible via high-temperature reaction from the elements in the appropriate substance amount ratio. Its crystal structure was determined from a Rietveld profile fit to an X-ray diffractogram of pristine RuZn3 and confirmed by single-crystal X-ray structure analysis. The title compound adopts a tetragonal Al3Zr-type structure corresponding to an A2B2 anti-phase domain structure of the cubic AuCu3-type: a=376.82(3) pm, c=1554.78(13) pm, I4/mmm, Z=4, R(F)(all data)=0.0197, 153 unique reflections, 12 variables. The structure is discussed in the light of the Hume-Rothery concept. RuZn3 melts at 1373(2) K, is a moderate metallic conductor (rho(293 K)=6.2 mOmega cm) and exhibits basically temperature-independent paramagnetic properties. It coexists with Ru1-xZnx and RuZn6.     

Synthesis,structure, and morphology of polymer–silica hybrid nanocomposites based on hydroxyethyl methacrylate

Two types of polymer–silica nanocomposites have been prepared by undergoing free radical polymerization of 2-hydroxyethyl methacrylate (HEMA) either in the presence of HEMA-functionalized SiO₂ nanoparticles (Type 1) or during the simultaneous in situ growing of the silica phase through the acid-catalyzed sol–gel polymerization of tetraethoxysilane (TEOS) (Type 2). Relationships between synthesis conditions, chemical structure, and resulting morphology have been studied. Type 1 systems exhibit a classical particle-matrix morphology, but where particles tend to form aggregates. Type 2 systems possess a finer morphology characterized by a very open mass-fractal silicate structure, which is believed to be bicontinuous with the organic phase at a molecular level. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 3172–3187, 1999     

Synthesis, crystal structure, and physical properties of sterically unprotected hydrocarbon radicals

We have prepared and isolated neutral polycyclic hydrocarbon radicals. A butyl-substituted radical gave single crystals, in which a π-dimeric structure, not a σ-bonded dimer, was observed, even though steric protection was absent. Thermodynamic stabilization due to the highly spin-delocalized structure contributes effectively to the suppression of σ-bond formation.     

Synthesis, chiroptical properties, and solid-state structure determination of two new chiral dipyrrin difluoroboryl chelates

Two new types of optically active BODIPY fluorophores bearing chiral phenyl substituents either at the meso-position or at both external alpha-positions have been synthesized. Their chiroptical properties are strongly dependent both on the position of the chiral group and on the protonation of the chromophore. The solid-state structures of one of the difluoroboryl chelates bearing the chiral phenyl substituent at the meso-position (9a) as well as of the corresponding ligand (8a) and its perchlorate have been determined by X-ray diffraction analysis. These are, to the best of our knowledge, the first crystal structures of a dipyrrin free base and of a dipyrrin salt which have been obtained by X-ray diffraction analysis. Hence, for the first time, the helical structure of a protonated dipyrrin chromophore has been proved experimentally.     

Synthesis, structure, solid-state thermal decomposition and magnetic properties of binuclear Nd, Gd and Eu cymantrenecarboxylates

New rare-earth cymantrenecarboxylates [Nd₂(μ₂-OOCCym)₄(OOCCym)₂(THF)₄] (1) and [Ln₂(μ₂-OOCCym)₄(OOCCym)₂(THF)₄]·THF (Ln = Gd (2), Eu (3); Cym = (η⁵-C₅H₄)Mn(CO)₃) were synthesized starting from carboxycymantrene and lanthanide nitrates, and characterized by X-ray diffraction. The crystals of 1-3 consist of isolated binuclear molecules; the Ln atoms are eight-coordinate. The magnetic properties of 2 are indicative of antiferromagnetic coupling between the Gd atoms at liquid helium temperature. The thermal decomposition of complexes 1-3 was studied by differential scanning calorimetry (DSC) and thermogravimetry (TG). According to the X-ray powder diffraction patterns, the thermal decomposition of the complexes in air affords a mixture of LnMn₂O₅ and Mn₂O₃ as the final products.     

Ferrocenyl oligophenothiazines as organic-organometallic hybrid electrophores - Synthesis, structure, and electronic properties

Oligomeric ferrocene-phenothiazine systems, a novel class of organometallic-organic hybrid electrophores, are easily accessible by Suzuki coupling of iodo ferrocenes and phenothiazinyl and diphenothiazinyl pinacolyl boronates. The triad and the pentad with 1,1′-disubstitution on ferrocene adopt preferentially an eclipsed orientation as a consequence of partial intramolecular π-stacking. In cyclic voltammetry the central ferrocenyl unit acts as an electronic communicator between phenothiazinyl side chains.     

Synthesis,structure, and magnetic properties of two new vanadocarboxylates with three-dimensional hybrid frameworks

(V(III)(OH))(2)[C(6)H(2)(CO(2))(4)].4H(2)O (labeled MIL-60) and V(III)(OH)[(2)(O(2)C)C(6)H(2)(COOH)(2)].H(2)O (labeled MIL-61) were hydrothermally synthesized from mixtures of VCl(3), 1,2,4,5-benzenetetracarboxylic acid, and water heated for 3 days at 473 K. The structure of MIL-60 was solved from single-crystal X-ray diffraction data in the triclinic centrosymmetric P1 (No. 2) space group with lattice parameters a = 6.3758(5) A, b = 6.8840(5) A, c = 9.0254(5) A, alpha = 69.010(2) degrees, beta = 85.197(2) degrees, gamma = 79.452(2) degrees, V = 363.53(5) A(3), and Z = 1. The structure of MIL-61 was ab initio determined from an X-ray powder diffraction pattern. MIL-61 crystallizes in the Pnma (No. 62) orthorhombic space group with lattice parameters a = 14.8860(1) A, b = 6.9164(1) A, c = 10.6669(2) A, V = 1098.23(3) A(3), and Z = 4. Both structures contain the same inorganic building block that consists of trans chains of V(III)O(4)(OH)(2) octahedra. The three-dimensional frameworks of MIL-60 and MIL-61 are constituted by the linkage of these chains via the organic molecules so delimiting the channels or cages where the water molecules are encapsulated. The magnetic behavior of these two phases is presented: MIL-60 is paramagnetic, and MIL-61 antiferromagnetically orders below T(N) = 55(5) K.     

Cellulose nanomaterials review: structure, properties and nanocomposites

This critical review provides a processing-structure-property perspective on recent advances in cellulose nanoparticles and composites produced from them. It summarizes cellulose nanoparticles in terms of particle morphology, crystal structure, and properties. Also described are the self-assembly and rheological properties of cellulose nanoparticle suspensions. The methodology of composite processing and resulting properties are fully covered, with an emphasis on neat and high fraction cellulose composites. Additionally, advances in predictive modeling from molecular dynamic simulations of crystalline cellulose to the continuum modeling of composites made with such particles are reviewed (392 references).     

Synthesis,structure, and physical properties of the new layered ternary chalcogenide NbNiTe5

The new ternary chalcogenide NbNiTe₅ has been prepared. NbNiTe₅ crystallizes with four formula units in a cell with dimensions a = 3.656(5), b = 13.075(16), c = 15.111(19) Å in the orthorhombic system in space group D¹⁷_2h-Cmcm. The structure has been refined to a final R index on F²_o of 0.037 for 25 variables and 1405 observations. NbNiTe₅ forms in a new layered structural type. Each layer consists of bicapped trigonal prismatic niobium atoms and octahedral nickel atoms coordinated by tellurium atoms. Electrical conductivity measurements indicate that NbNiTe₅ is a metal; its conductivity at room temperature is about 1.3 × 10⁴ Ω⁻¹ cm⁻¹. Magnetic susceptibility measurements show that NbNiTe₅ is paramagnetic (X_rt ≈ 1.04 × 10⁻³ emu mole⁻¹).     

Synthesis,structure and physical properties of the one-dimensional chain complex of tetrathiafulvalene carboxylate

A new Co(II) coordination polymer bearing TTF carboxylate group, [{Co₂(trioTTF)₂(H₂O)₆}·5H₂O]_n (1) (trioTTF = 2-(5,6,8,9,11,12,14,15-octahydro-[1,3]dithiolo[4,5-h][1,4,13,7,10]trioxadithiacyclopentadecin-2-ylidene)-1,3-dithiole-4,5-dicarboxylate), has been prepared and characterized. In the structure of 1, shorter intermolecular S····S contacts (3.565 Å) are found between the trioTTF groups from neighboring chains. The electric conductivity of 1 is poor due to the bulky crown-ether group, but it exhibits ferromagnetic interaction at low temperature.     

Synthesis, structure, and physical properties of a new anions-controlled Cd(II)-guanazole (3,5-diamino-1,2,4-triazole) hybrid family

Nine members of a new anions-controlled Cd(II)-guanazole (3,5-diamino-1,2,4-triazole=Hdatrz) hybrid family, that is, [Cd3(datrz)6(H2O)2] (1), [Cd3(datrz)4F2] (2), [Cd5(datrz)4Cl4(OH)2] (3), [Cd5(datrz)4Br4(OH)2] (4), [Cd3(datrz)2(SO3)2].(H2O) (5), [Cd3(datrz)2(O2CMe)4] (6), [Cd(datrz)(O2CEt)] (7), [Cd(Hdatrz)(O2CtBu)2] (8), and [Cd(Hdatrz)2(H2Edta)] (9) have been synthesized by exploiting hydrothermal reactions of guanazole with suitable cadmium salts under appropriate reaction conditions. With effective control of inorganic or organic anions, the coordination diversity of the guanazole ligand in 1-9 manifests an unprecedented enrichment with five bridging modes varying from bidentate to quadridentate, two of which are first reported. Compound 1 is the first reported three-dimensional chiral complex constructed from the guanazole ligand which adopts a novel N1, N2, amino N-bridging mode. Halogen anions F-, Cl-, and Br- controlled compounds 2-4 are all three-dimensional, with their guanazole ligands possessing another novel quadridentate bridging mode. Sulfite anions controlled compound 5 displays a three-dimensional network with peculiar cage-like hexnuclear cadmium clusters. As for organic anions, low dimensional structures have been found for alkylcarboxylate anions MeCO2-, EtCO2-, and tBuCO2- controlled compounds 6, 7, and 8 (two-dimensional) and for H2Edta2- controlled compound 9 (zero-dimensional), and their guanazole ligands manifest low coordination numbers as well. These hybrid materials also present interesting structure-induced physical properties. The chiral compound 1 exhibits the second-order nonlinear optical properties at room temperature. Compounds 2-9 except 6 all exhibit photoluminescence of blue fluorescent emissions in the solid state at ambient temperature, which may be assigned to the intraligand pi-pi* transitions. Some structure related red or blue emission shifts have been investigated. Thermal studies show that most compounds of this study possess a high thermal stability.     

Synthesis and solid-state structure of perfluorophenyl end-capped polyynes

Five new supramolecular building blocks have been synthesized on the basis of polyynes end-capped with pentafluorophenyl groups, including three symmetrical (16, 17, 18) and two unsymmetrical polyynes (7 and 12). The solid-state behavior of these molecules based on the attractive electrostatic interactions of the phenyl and perfluorophenyl groups has been examined by X-ray crystallographic analysis of 7, 12, and 16.25.     

Synthesis,crystal structure,photoluminescence properties of organic-inorganic hybrid materials based on ethylenediamine bromide

In this work, a new orthorhombic organic-inorganic hybrid single crystal (C₂H₁₀N₂)₂MnBr₄.2Br with-Zero-dimensional structure was synthesized by slow evaporation method at 75 °C. The crystal structure and intermolecular interactions were performed by single crystal X-ray diffraction and Hirshfeld surface. Optical properties of (C₂H₁₀N₂)₂MnBr₄.2Br were systematically studied by Raman, infrared spectrum, UV–vis, photoexcitation spectra, and photoluminescence spectra. The optical band gap (E_g = 2.61 eV) were calculated from the absorption spectra of (C₂H₁₀N₂)₂MnBr₄.2Br. This hybrid materials also had shown good thermal stability (decomposition temperature: 288–660 °C). Finally, photoluminescence measurements showed a strong excitation line at 362 nm and a strong fluorescence at 537 nm which makes it a promising material in luminescence field.     

Synthesis,solid-state photophysical properties and electropolymerization of novel diazulenyl ethenes

The novel 1,2-di(azulen-1-yl)cyclopent-1-ene 3 was conveniently synthesized via a two-step procedure involving Vilsmeier–Haack acylation of azulene with N,N,N′,N′-tetraethylglutaramide (TEGA) and POCl₃, followed by an intramolecular McMurry coupling of the resulting diketone. In contrast with the previously reported (E)-1,2-di(azulen-1-yl)ethene that shows negligible fluorescence in the solid state, alkene 3 displays fluorescence emission from the S₂ excited state of the azulene moieties. This compound easily polymerizes upon electrochemical oxidation, leading to the formation of a conducting polymer film at the electrode surface.