Grafting isophthalic acid groups to linear connectors produces tetracarboxylic acids 2−4, which are extended analogues of trimesic (1). Normal pairwise association -COOH induces form a hexagonal network held together by six hydrogen bonds per molecule. In contrast, 2−4 designed two polymorphs, parallel II and Kagomé III, linked eight The particular connectivity these networks allows smooth transition from one the other without introducing discontinuities in bonding. DFT calculations suggest...

We demonstrate a surprising cooperative adsorption process at the liquid−solid interface, involving self-assembly in which three-fold hydrogen-bonding unit (trimesic acid, TMA) is forced into linear pattern by noncovalent interaction with an alcohol. Our work shows that unexpected formed coadsorption of TMA and alcohols can be modulated size choosing different chain lengths.

A comparative density functional plus dynamical mean field theory study of the pseudocubic ruthenate materials ${\text{CaRuO}}_{3}$ and ${\text{SrRuO}}_{3}$ is presented. Phase diagrams are determined for both as a function Hubbard repulsion $U$ Hund's rule coupling $J$. Metallic insulating phases found, ferromagnetic paramagnetic states. The locations relevant phase boundaries determined. Based on computed diagrams, Mott dominated regimes strong correlation distinguished. Comparison...

We report the highly convergent synthesis and solid-state characterization of six crystalline "molecular compasses" consisting a central phenylene rotor with polar substituents, or compass needle, two trityl groups axially connected by acetylene linkages to 1,4-positions. Compounds fluoro-, cyano-, nitro-, amino-, diamino-, nitroamino substituents are expected emulate parent compound which was shown form crystals where can rotate about its 1,4-axis rate constants in 10(3) -10(6) s(-)(1)...

Samples of 1,4-bis(3,3,3-triphenylpropynyl)benzene 3 were prepared by Pd(0)-catalyzed coupling 3,3,3-triphenylpropyne (1) and 1,4-diiodobenzene. The structure compound is such that the central phenylene can play role a gyroscope wheel, while alkyne bond trityl groups act as an axle shielding frameworks, respectively. Crystals grown from benzene dichloromethane characterized X-ray diffraction, variable-temperature (13)C CPMAS NMR, quadrupolar echo solid-state (2)H thermal analyses. rotational...

We describe our efforts toward the preparation of materials built with molecules possessing topologies analogous to those macroscopic compasses and gyroscopes. Samples 1,4-bis(3,3,3-triphenylpropynyl)benzene (3) were prepared by a simple two-step procedure from triphenylmethyl chloride (1) 1,4-diiodobenzene. The structure compound 3 is such that central phenylene can play role gyroscope wheel while two tritylpropynyl groups act as an axle shielding framework. Crystals benzene clathrate...

Products of polyamine oxidase activity, at micromolar levels and during a period 2 to 3 days, down-regulate IL-2 mRNA activity in human lymphocytes. We studied whether this suppression was associated with signal transduction abnormalities. found that suppresses both anti-CD3-induced production protein tyrosine phosphorylation. Polyamine also caused reduction intracellular calcium mobilization after mitogenic stimulation. The most distal step CD3-mediated is dependent upon transcription...

A chemical study on the anti-inflammatory components of red alga Gracilaria verrucosa led to isolation new 11-deoxyprostaglandins (1–4), a ceramide (5), and C16 keto fatty acid (6), along with known oxygenated acids (7–14). Their structures were elucidated basis NMR MS data. The absolute configurations compounds 1–5 determined by Mosher's method. activity isolated (1–14) was evaluated determining their inhibitory effects production pro-inflammatory mediators (NO, IL-6, TNF-α) in...

In the course of our search for bioactive metabolites from a sponge-derived fungus Acremonium sp., new sesquiterpenoids (1−4) were isolated along with known derivatives by bioactivity-guided fractionation. The unique cyclic skeleton compounds 2 and 3 is unprecedented. absolute configurations determined modified Mosher's method CD spectroscopy, comparison 1H 13C NMR spectroscopic data specific optical rotation values those reported. anti-inflammatory activity (1, 5, 7−13) was evaluated...

Chiral phospholane ligands and catalysts have been widely applied in asymmetric catalysis synthesis. However, the construction of chiral skeleton remains challenging primarily relies on use auxiliaries or resolution. In this work, a highly enantioselective diastereoselective synthesis P-stereogenic oxides has achieved through cobalt-catalyzed desymmetric hydroalkylation strategy. This method enables two discrete stereocenters with excellent yields enantiomeric excesses.

We report a highly convergent synthesis for the preparation of molecular gyroscopes consisting para-phenylene rotors linked by triple bonds to methyl-substituted triptycenes acting as pivots and encapsulating frames. The desired 1,4-bis[2-(2,3,6,7,12,13-hexamethyl-10-alkyl-9-triptycyl)ethynyl]benzenes were prepared from 2,3-dimethyl-1,3-butadiene using Diels-Alder cycloadditions Pd(0)-catalyzed coupling key reactions. main challenge in came about 9-alkynyl-triptycenes reaction benzynes...

revealed the presence of an amino alcohol unit (Lol, leucine-derived leucinol), com-mon acid units (asparagine and glutamine), a fatty acyl chain (3-hydroxydodecanoic acid). The leu-cinol (Lol) moiety was apparent from COSY correlation hydroxymethylene protons at δ 3.46 (H-β'), with

Korea Research Institute of Chemical Technology, Daejon 305-343, Received August 11, 2011, Accepted 30, 2011Key Words : Cytotoxicity, Aspergillus versicolor, Sponge-derived fungus, FellutamideRecently, a series linear lipopeptides containing unusualamino acid residues have been reported from marine fungi,and these serve as valuable source potential drug leads.These were found to interesting bio-activities, including, anti-inflammatory, antimalarial proper-ties, antimicrobial,...

The combination of density functional theory and single-site dynamical mean-field theory, using both Hartree full continuous-time quantum Monte Carlo impurity solvers, is used to study the metal-insulator phase diagram perovskite transition-metal oxides form $AB$O$_3$ with a rare-earth ion $A$=Sr, La, Y transition metal $B$=Ti, V, Cr. correlated subspace constructed from atomiclike $d$ orbitals defined maximally localized Wannier functions derived $p$-$d$ manifold; for comparison, results...

A simple procedure for the synthesis of cyclopentafused polycyclic aromatic hydrocarbons (CP-PAH) with Pd(PPh3)2Cl2 catalyst has been applied to one-pot palladium(0)-catalyzed coupling 9,10-dibromoanthracene (1) 2-methyl-3-butyn-2-ol. Reactions carried out in refluxing benzene presence CuSO4/Al2O3 yielded 9,10-dialkynylanthracene 2a, alkynyl aceanthrylene 2b, and 2,7-disubstituted cyclopent[hi]aceanthrylene 2c 13%, 23%, 19% purified yields, respectively, total conversions 80−90%. Sealed tube...

A combination of solid-state 13C CPMAS NMR, 2H X-ray-determined anisotropic displacement parameters (ADPs), and molecular mechanics calculations were used to analyze the rotational dynamics 1,4-bis[3,3,3-tris(m-methoxyphenyl)propynyl]benzene (3A), a structure that emulates gyroscope with p-phenylene group acting as rotator two m-methoxy-substituted trityl groups stator. The line shape analysis VT broad-band NMR data in remarkable agreement each other, barriers 11.3 11.5 kcal/mol,...

A combination of density functional and dynamical mean-field theory is applied to the perovskites SrVO$_3$, LaTiO$_3$ LaVO$_3$. We show that DFT+DMFT in conjunction with standard fully localized-limit (FLL) double-counting predicts LaVO$_3$ are metals even though experimentally they correlation-driven ("Mott") insulators. In addition, FLL double counting implies a splitting between oxygen $p$ transition metal $d$ levels which differs from experiment. Introducing into an \textit{ad hoc}...

Density functional plus dynamical mean field calculations are used to show that in transition metal oxides, rotational and tilting (GdFeO(3)-type) distortions of the ideal cubic perovskite structure produce a multiplicity low-energy optical transitions which affect conductivity down frequencies order 1 or 2 mV (terahertz regime), mimicking non-Fermi-liquid effects even systems with strictly Fermi-liquid self-energy. For CaRuO(3), material whose measured electromagnetic response terahertz...

We present density functional plus dynamical mean field studies of cubic BaRuO$_3$ using interaction parameters previously found to be appropriate for the related materials CaRuO$_3$ and SrRuO$_3$. The calculated variation in transition temperature between Ba Sr compounds is consistent with experiment, confirming assignment Hund's metal family materials, also appropriateness values estimated single-site approximation these materials. results provide insights into origin magnetism role van...

We report the synthesis and photophysical properties of 1,4-bis(9-ethynylanthracenyl)benzene. Results in dilute hexane solutions give a very high fluorescence quantum yield (Φ = 0.97) lifetime τ 1.8 ns. Studies at different temperatures, viscosities, micromorphologies, as well excited-state semiempirical calculations, indicate that conformations having aryl groups coplanar absorb emit wavelengths are longer than those have their orthogonal or twisted. A simple MO picture is consistent with...

Based on dynamical cluster approximation (DCA) quantum Monte Carlo simulations, we study the interaction-driven Mott metal-insulator transition (MIT) in half-filled Hubbard model anisotropic two-dimensional triangular lattice, where degree of frustration is varied between unfrustrated case and fully frustrated, isotropic lattice. Upon increasing DCA size, analyze evolution MIT phase boundary as a function diagram spanned by interaction strength temperature, provide quantitative description...