Bis(μ-naphthalene-1,8-dicarboxyl­ato)bis­[aqua­(2,2′-bipyridine)zinc(II)] tetra­hydrate

The title complex, [Zn2(C12H6O4)2(C10H8N2)2(H2O)2]·4H2O, is a binuclear complex with two independent ZnII ions in a slightly disorted trigonal bipyramidal environment, coordinated by one aqua ligand, two naphthalene-1,8-dicarboxyl­ate ligands and one 2,2′-bipyridine ligand. π–π Inter­actions [centroid–centroid distance of 3.8489 (5) Å] and O—H⋯O hydrogen bonds connect the mol­ecules, forming a three-dimensional structure

Novel Brønsted-acidic ionic liquids based on benzothiazolium cations as catalysts for esterification reactions

Three novel Brønsted-acidic ionic liquids based on benzothiazolium cations were prepared, which served as catalysts for the synthesis of benzoic esters. All three gave good yields of the target esters in esterification reactions. Moreover, they combine the advantages of both homogeneous and heterogeneous solid catalysts in esterification reactions, which enabled them to serve as homogeneous catalysts to catalyze the reactions and be conveniently recovered by simple filtration after the reactions. They could be reused several times without noticeable decrease in efficiency

Tetrakis[μ-3-(3-hy­droxy­phen­yl)propenoato]bis­{aqua­(2,2′-bipyridine)­[3-(3-hy­droxy­phen­yl)propenoato]neodymium(III)} 2,2′-bipyridine disolvate dihydrate

The dinuclear title compound, [Nd2(C9H7O3)6(C10H8N2)2]·2C10H8N2·2H2O, was synthesized under hydro­thermal conditions. The centrosymmetric complex consists of two nine-coordinated Nd3+ cations, six 3-hy­droxy­cinnamate anions and two chelating 2,2′-bipyridine mol­ecules. The coordination geometry around the cations can be best described as distorted tricapped trigonal-prismatic. The carboxyl­ate groups show different coordination and bridging modes. Two of them chelate to one Nd3+ cation, two bridge the two cations in a bis-monodentate fashion, and two chelate to one and bridge monodentately to the symmetry-related Nd3+ cation. The dinuclear mol­ecule is surrounded by two 2,2′-bipyridine solvent and two water mol­ecules. Extensive O—H⋯O and O—H⋯N hydrogen-bonding inter­actions between the components lead to the formation of a three-dimensional network

Key Aquatic Environmental Factors Affecting Ecosystem Health of Streams in the Dianchi Lake Watershed, China

AbstractStreams in a lake watershed are important landscape corridors which link the lake and terrestrial ecosystems. Therefore, the ecosystem health of streams is usually used to indicate aquatic biodiversity of the lake ecosystem, as well as being affected by aquatic environmental factors in response to changes in land use cover of the terrestrial ecosystem due to natural geographic characteristics of the watershed with the closure of ridge lines. This study was carried out at a shallow freshwater lake watershed in the Yunnan-Guizhou Plateau of China, the Dianchi Lake watershed (DLW). Field survey of periphytic algal and macrozoobenthic biodiversity during July and August of 2009, as well as monthly monitoring of water temperature, pH, TSS, DO, TN, TP, NH3N, NO3N, CODMn, BOD, TOC, and the heavy metals Zn (II), Cd (II), Pb (II), Cu (II), and Cr (VI) from January to December 2009 was carried out in 29 streams flowing into Dianchi lake. Multivariate statistical techniques such as factor analysis and canonical correspondence analysis were applied to analyze the structure of the aquatic community in relation to aquatic environmental factors in order to provide controlling objectives for integrated watershed management and improvement of stream rehabilitation in the DLW. The results showed that the structure of the periphytic algal and macrozoobenthic communities were dominated by pollution-tolerant genera, namely the bacillariophytes Navicula and the annelids Tubificidae respectively, and TN, NH3N and TP were key aquatic environmental factors affecting the ecosystem health of streams in the DLW

Poly[[tetraaqua­bis(μ3-1H-benzimidazole-5,6-dicarboxyl­ato)dicobalt(II)] trihydrate]

The title complex, {[Co2(C9H4N2O4)2(H2O)4]·3H2O}n, was synthesized hydro­thermally. The unique CoII ion is coordin­ated in a distorted octa­hedral coordination environment by two water mol­ecules and three symmetry-related 1H-benzimid­azole-5,6-dicarboxyl­ate (Hbidc) ligands. The Hbidc ligands coordinate via a bis-chelating and mono-chelating carboxyl­ate group and by an imidazole group N atom, bridging the CoII ions and forming an extended two-dimensional structure in the ab plane. In the crystal structure, inter­molecular N—H⋯O and O—H⋯O hydrogen bonds connect complex and solvent water mol­ecules, forming a three-dimensional supermolecular network. One of the solvent water mol­ecules lies on a twofold rotation axis

Bis(μ-naphthalene-1,8-dicarboxyl­ato-κ2 O 1:O 8)bis­[aqua­bis­(N,N′-dimethyl­formamide-κO)copper(II)]

In the centrosymmetric dinuclear title complex, [Cu2(C12H6O4)2(C3H7NO)4(H2O)2], the coordination environment of each Cu(II) atom displays a distorted CuO5 square-pyramidal geometry, which is formed by two carboxyl­ate O atoms of two μ-1,8-nap ligands (1,8-nap is naphthalene-1,8-dicarboxyl­ate), two O atoms of two DMF (DMF is N,N′-dimethyl­formamide) and one coordinated water mol­ecule. The Cu—O distances involving the four O atoms in the square plane are in the range 1.9501 (11)–1.9677 (11) Å, with the Cu atom lying nearly in the plane [deviation = 0.0726 (2) Å]. The axial O atom occupies the peak position with a Cu—O distance of 2.885 (12) Å, which is significantly longer than the rest of the Cu—O distances. Each 1,8-nap ligand acts as bridge, linking two CuII atoms into a dinuclear structure. Inter­molecular O—H⋯O and C—H⋯O hydrogen-bonding inter­actions consolidate the structure

The Incentive Mechanism with RFID Technology for Suppliers to Design Environmentally-Friendly Electrical and Electronic Equipment

AbstractTaiwan EPA has promulgated Resource Recycling Act in 2002, which is formulated to conserve natural resources, reduce waste, promote recycling and reuse of materials, mitigate environmental loading, and build a society in which resources are used in a sustainable manner. [1] Since 1998, the recycling of waste large household appliances such as televisions, washing machines, refrigerators, and air conditioners, etc. has been implemented; waste electric fans and waste computer keyboards were also included in 2007. Although recycling in Taiwan initiated early, whether waste electrical and electronic equipment recycling is just the process of decomposition, recycling, incineration, and landfill, rather than extending the product lifespan, need further studies to confirm that.The Recycling Fund Management Board takes charge of the operation of recycling mechanism in Taiwan. The funds mostly paid by the businesses as the recycling, clearance and disposal fees. Such fees now are unified under the same products specifications. The existed system can’t provide products under the same specifications but with longer lifespan more preferential fees, which means that there is no incentive for the suppliers to improve the design of products.With Radio Frequency Identification (RFID) inserted in, the household appliances will not only have the basic information about the product, but also can keep track of the purchase and maintenance record, as well as the disposal date and location, during the use stage of that product. Such record provides information on the service life of the product, and the recycling fees paid by businesses could be returned relative to the lifetime to the consumers accordingly. The new mechanism incentives the suppliers to consider the product durability in design and manufacture stages that helps achieve the goal to make products decomposable, recyclable, and lifetime extended

2-[4-(Carb­oxy­meth­yl)phen­oxy]acetic acid

The title compound, C10H10O5, was obtained by the reaction of 4-hy­droxy­phenyl­acetic acid with chloro­acetic acid. In the crystal, the mol­ecules form a three-dimensional network by way of inter­molecular O—H⋯O hydrogen bonding