LiSc(BH4)4: a novel salt of Li+ and discrete Sc(BH4)4(-) complex anions

LiSc(BH4)4 has been prepared by ball milling of LiBH4 and ScCl3. Vibrational spectroscopy indicates the presence of discrete Sc(BH4)4(-) ions. DFT calculations of this isolated complex ion confirm that it is a stable complex, and the calculated vibrational spectra agree well with the experimental ones. The four BH4(-) groups are oriented with a tilted plane of three hydrogen atoms directed to the central Sc ion, resulting in a global 8 + 4 coordination. The crystal structure obtained by high-resolution synchrotron powder diffraction reveals a tetragonal unit cell with a = 6.076 A and c = 12.034 A (space group P-42c). The local structure of the Sc(BH4)4(-) complex is refined as a distorted form of the theoretical structure. The Li ions are found to be disordered along the z axis.     

Angiopoietin-1 variant, COMP-Ang1 attenuates hydrogen peroxide-induced acute lung injury

Reactive oxygen species (ROS) play a crucial role in acute lung injury. Tissue inflammation, the increased vascular permeability, and plasma exudation are cardinal features of acute lung injury. Angiopoietin-1 (Ang1) has potential therapeutic applications in preventing vascular leakage and also has beneficial effects in several inflammatory disorders. Recently developed COMP-Ang1 is more potent than native Ang1 in phosphorylating tyrosine kinase with immunoglobulin and EGF homology domain 2 receptor in endothelial cells. However, there are no data on effects and related molecular mechanisms of COMP- Ang1 on ROS-induced acute lung injury. We used hydrogen peroxide (H2O2)-inhaled mice to evaluate the effect of COMP-Ang1 on pulmonary inflammation, bronchial hyper-responsiveness, and vascular leakage in acute lung injury. The results have revealed that VEGF expression, the levels of IL-4, TNF-alpha, IL-1beta, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 in lungs, the levels of hypoxia-inducible factor-1alpha (HIF-1alpha) and NF-kappaB in nuclear protein extracts, phosphorylation of Akt, and vascular permeability were increased after inhalation of H2O2 and that the administration of COMP-Ang1 markedly reduced airway hyper-responsiveness, pulmonary inflammation, plasma extravasation, and the increases of cytokines, adhesion molecules, and VEGF in lungs treated with H2O2. We have also found that the activation of HIF-1a and NF-kB and the increase of phosphoinositide 3-kinase activity in lung tissues after H2O2 inhalation were decreased by the administration of COMP-Ang1. These results suggest that COMP-Ang1 ameliorates ROS-induced acute lung injury through attenuating vascular leakage and modulating inflammatory mediators.     

Rational design of cationic cyclooligosaccharides as efficient gene delivery systems

Self-assembled cyclodextrin (CD)-DNA nanoparticles (CDplexes) exhibiting transfection efficiencies significantly higher than PEI-based polyplexes have been prepared from homogeneous seven-fold symmetric polyaminothiourea amphiphiles constructed on a beta-cyclodextrin scaffold.     

Biphasic hydroformylation in ionic liquids: interaction between phosphane ligands and imidazolium triflate, toward an asymmetric process

Biphasic hydroformylation of dec-1-ene and styrene, at commercially competitive rates, can be successfully performed in imidazolium triflate ionic liquids; the ionic liquid network forms 'inclusion complexes' with the phosphane ligands used to modify the rhodium catalyst.     

Accelerating charge transfer in a triphenylamine-subphthalocyanine donor-acceptor system

We have designed, synthesized and probed a dodecafluoro-subphthalocyaninato boron(III) unit, which bears a triphenylamine moiety in its axial position, as a novel electron donor-acceptor system.     

Regularity of solutions of Poisson’s equation in multiplier spaces

The most important result stated in this paper is to show that the solutions of the Poisson equation −Δu = f, where f ∈ (Ḣ¹(ℝ ^d ) → (Ḣ⁻¹(ℝ ^d )) is a complex-valued distribution on ℝ ^d , satisfy the regularity property D ^k u ∈ (Ḣ¹ → Ḣ⁻¹) for all k, |k| = 2. The regularity of this equation is well studied by Maz’ya and Verbitsky [12] in the case where f belongs to the class of positive Borel measures.      

Designer amphiphiles based on para-acyl-calix[8]arenes

The synthesis of a series of fully O-derivatised para-acyl-calix[8]arenes is described, where the acyl function is either octanoyl or hexadecanoyl. The groups attached at the phenolic face are, carboxymethoxy (anionic), carboxypropoxy (anionic), 4-sulfonatobutoxy (anionic), ethoxycarboxymethoxy (neutral), ethoxycarboxypropoxy (neutral), 2-methoxyethoxy (neutral) and 2-(2-methoxy)diethoxy (neutral). The use of specific synthetic routes has allowed complete substitution in high yields for all the compounds obtained. The interfacial properties of the compounds have been studied and stable monolayers have been obtained for certain compounds in the series having para-octanoyl substituents; all compounds studied in the series having para-hexadecanoyl substituents formed stable monolayers at the air-water interface. The interactions between O-4-sulfonatobutoxy-para-ocatanoylcalix[8]arene and a series of serum albumins have been studied by dynamic light scattering and specific adsorption of the calix-[8]-arene derivative onto the proteins observed. The anionic derivatives O-4-sulfonatobutoxy-para-ocatanoylcalix[8]arene and O-carboxymethoxy-para-ocatanoylcalix[8]arene have been shown to possess anticoagulant properties but to have no haemolytic toxicity.     

Microscopic approaches to liquid nitromethane detonation properties

In this paper, thermodynamic and chemical properties of nitromethane are investigated using microscopic simulations. The Hugoniot curve of the inert explosive is computed using Monte Carlo simulations with a modified version of the adaptative Erpenbeck equation of state and a recently developed intermolecular potential. Molecular dynamic simulations of nitromethane decomposition have been performed using a reactive potential, allowing the calculation of kinetic rate constants and activation energies. Finally, the Crussard curve of detonation products as well as thermodynamic properties at the Chapman-Jouguet (CJ) point are computed using reactive ensemble Monte Carlo simulations. Results are in good agreement with both thermochemical calculations and experimental measurements.     

Study of the supramolecular cooperativity in the multirecognition mechanism of cyclodextrins/cucurbituril/disubstituted diimidazolium bromides

N, N'-Disubstituted methylenediimidazolium bromide salts substituted with two aromatic groups present two different binding sites. In the binary complexes with cyclodextrins (CDs) or cucurbit[7]uril (CB[7]), the macrocycle is always positioned on the external aromatic residues. In the ternary complexes, CB[7] is positioned around the diimidazolium cation, where the external aromatic residue is included in the CD's cavity. The unfavored position of the CB[7] on the cationic site in the ternary complex is the result of its cooperative supramolecular interaction with the cyclodextrin. The obtained ternary complexes possess different interfacial properties, compared to those of the binary complexes. We demonstrate these hypotheses by NMR spectroscopy, ESI-HRMS spectrometry, molecular modeling simulation, and surface tension measurements.