An unprecedented 2D covalent organic framework with an htb net topology.

A 2D imine-linked COF with a hitherto unreported htb type topology was synthesized from a linear diamine linker and a judiciously designed tetra-aldehyde building block. This work opens the door to the development of COFs with unprecedented topologies and may broaden the scope of COF functional materials by pore size and pore surface engineering

Atmospheric mercury inputs in montane soils increase with elevation: evidence from mercury isotope signatures

The influence of topography on the biogeochemical cycle of mercury (Hg) has received relatively little attention. Here, we report the measurement of Hg species and their corresponding isotope composition in soil sampled along an elevational gradient transect on Mt. Leigong in subtropical southwestern China. The data are used to explain orography-related effects on the fate and behaviour of Hg species in montane environments. The total- and methyl-Hg concentrations in topsoil samples show a positive correlation with elevation. However, a negative elevation dependence was observed in the mass- ependent fractionation (MDF) and mass-independent fractionation (MIF) signatures of Hg isotopes. Both a MIF (D199Hg) binary mixing approach and the traditional inert element method indicate that the content of Hg derived from the atmosphere distinctly increases with altitude.publishedVersio

Poly[aqua(μ3-5-aza­niumylisophthalato)­(μ-oxalato)neodymium(III)]

The title compound, [Nd(C8H6NO4)(C2O4)(H2O)]n, is a layer-like coordination polymer. The NdIII ion is coordinated by four carboxyl­ate O atoms from three bridging 5-aza­nium­yl­isophthalate (Haip) ligands, four carboxyl­ate O atoms from two oxalate (ox) anions and one ligated water mol­ecule in a tricapped trigonal–prismatic geometry. The Haip anion acts as a μ3-bridge, connecting three NdIII ions through two carboxyl­ate groups; the ox anion adopts a bis-bidentate-bridging mode, linking two NdIII ions. The layer framework is further extended to a three-dimensional supra­molecular structure through N—H⋯O and O—H⋯O hydrogen bonds

Triterpenoids and Sterols from the Leaves and Twigs of Melia azedarach

Two new triterpenoids (1 and 2) and a new sterol (3), together with six known constituents (4–9), were isolated from the leaves and twigs of Melia azedarach. Their chemical structures were elucidated on the basis of spectroscopic analysis. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13659-014-0019-1) contains supplementary material, which is available to authorized users

Toxicities comparison of rotenone and acetone extract of Tephrosiavogelii and Derris trifoliate against Solenopsis invicta

The high rotenone content and the rotenone crude extract of Tephrosia vogelii and Derris trifoliata were evaluated for its efficacy in the control of red imported fire (RIFA), Solenopsis invicta under both laboratory and field conditions. The acetone extracts of D. trifoliata roots and T. vogelii leaves exhibited strong toxicity to macroergate and micrergate of RIFA. When active ingredients of the crude extracts were convert to rotenone, the activity of the acetone extracts were higher than that of rotenone technical material. At the same time, the extracts showed significant inhibitory effect on walking ability and grasping ability of worker ants and stronger than the effect of 98.6% rotenone technical material. Under field conditions, the 0.01% rotenone-bait, formulated with the acetone extract of D. trifoliata roots and T. vogelii leaves, had the same control effect on RIFA as that of 0.01% fipronil-bait when treated after 30 d. The bait formulated with the extract of D. trifoliata exhibited quicker and higher effect on RIFA than that of rotenone technical material. It was showed that the acetone extracts of D. trifoliata roots and T. vogelii leaves are able to control S. invicta under both laboratory and field conditions and can be used as an effective agent against RIFA

Dimension Increase via Hierarchical Hydrogen Bonding from Simple Pincer-like Mononuclear complexes

A tetradentate symmetric ligand bearing both coordination and hydrogen bonding sites, N1,N3-bis(1-(1H-benzimidazol-2-yl)-ethylidene)propane-1,3-diamine (H2bbepd) was utilized to synthesize a series of transition metal complexes, namely [Co(H2bbepd)(H2O)2]·2ClO4 (1), [Cu(H2bbepd)(OTs-)]·OTs- (2),[Cu(bbepd)(CH3OH)] (3), [Cd(H2bbepd)(NO3)2]·CH3OH (4), [Cd(H2bbepd)(CH3OH)Cl]·Cl (5), and [Cd(bbepd)(CH3OH)2] (6). These complexes show similar discrete pincer-like coordination units, possessing different arrangements of hydrogen bonding donor and acceptor sites. With or without the aid of uncoordinated anions and solvent molecules, such mononuclear units have been effectively involved in the construction of hierarchical hydrogen bonding assemblies (successively via level I and level II), leading to discrete binuclear ring (complex 2), one-dimensional chain or ribbon (complexes 3, 4 and 6) and two-dimensional layer (complexes 1 and 5) aggregates

Manipulating Multiple Order Parameters via Oxygen Vacancies: The case of Eu0.5Ba0.5TiO3-{\delta}

Controlling functionalities, such as magnetism or ferroelectricity, by means of oxygen vacancies (VO) is a key issue for the future development of transition metal oxides. Progress in this field is currently addressed through VO variations and their impact on mainly one order parameter. Here we reveal a new mechanism for tuning both magnetism and ferroelectricity simultaneously by using VO. Combined experimental and density-functional theory studies of Eu0.5Ba0.5TiO3-{\delta}, we demonstrate that oxygen vacancies create Ti3+ 3d1 defect states, mediating the ferromagnetic coupling between the localized Eu 4f7 spins, and increase an off-center displacement of Ti ions, enhancing the ferroelectric Curie temperature. The dual function of Ti sites also promises a magnetoelectric coupling in the Eu0.5Ba0.5TiO3-{\delta}.Comment: Accepted by Physical Review B, 201