Au(I) extraction by LIX-79/n-heptane using the pseudo-emulsion-based hollow-fiber strip dispersion (PEHFSD) technique

The extraction of Au(I) from alkaline cyanide solutions through PEHFSD was conducted in a microporous hydrophobic polypropylene hollow-fiber membrane contactor. The organic extractant LIX-79 (N,N-bis(2-ethyl hexyl)guanidine) in n-heptane was used. The alkaline cyanide feed solution containing Au(I) was passed through the tube side, and pseudo-emulsions of LIX-79/n-heptane and NaOH were passed through the shell side in counter-current mode, using a single microporous hydrophobic polypropylene hollow-fiber contactor for extraction and stripping. In PEHFSD the aqueous strip (0.2 M NaOH) solution is dispersed in the organic (12% LIX-79/n-heptane) membrane solution in a container with a mixing arrangement (impeller stirrer) designed to form a strip dispersion. The strip dispersion is circulated from the mixer to the membrane module to provide a constant supply of the LIX-79/n-heptane solution to the membrane pores. Various hydrodynamic and chemical parameters, such as variation in feed pH; gold cyanide concentration in feed; variation in concentrations of NaOH, LIX-79/n-heptane and Au(I); variation in feed, strip and LIX-79/n-heptane volume ratios and variation in feed and strippant flow rates, were investigated. Mass transfer modeling was performed and the validity of the model was evaluated with experimental data and found to tie in well with theoretical values. It was possible to concentrate Au(I) in product (NaOH) using the PEHFSD technique.     

Selective encapsulation of volatile and reactive methyl iodide

A simple organic molecular container can selectively encapsulate the volatile and highly reactive MeI through hydrogen-bonding interactions in solution. The remarkable encapsulation of MeI without self-methylation of the container appears to be determined by the complementary binding sites and the rigidity of the hydrogen-bonding array constrained by the molecular framework.     

ChemInform Abstract: Isolated Zirconium Chloride Clusters in the Phase Rb5Zr6Cl18B (I). Generalities Regarding the Bonding,Stability, and Size of M6X12-Type Clusters with and without Interstitial Atoms.

(I) is prepared in high yield by reaction of Zr, B, RbCl, and ZrCl₄ in a sealed Ta container at 850 °C. It crystallizes in the space group Pmna with Z=2.     

Photochemical generation and reactivity of carbenes within an organic cavitand and capsule: photochemistry of adamantanediazirines

Chemical behavior of carbenes (adamantylidenes) generated by photolysis of adamantanediazirines has been investigated while they were incarcerated within an organic container in water and on silica surfaces. Confined carbenes behave differently from the free ones, and their behavior is dictated by the nature and the structure of the host-guest complexes. The substituent present on the adamantyl skeleton controls the stoichiometry (1:1 or 2:2) and the orientation of guest molecules within the host.     

Anion Exchange Renders Hydrophobic Capsules and Cargoes Water-Soluble

Control over the solubility properties of container molecules is a central challenge in host–guest chemistry. Herein we present a simple anion-exchange protocol that allows the dissolution in water of various hydrophobic metal–organic container molecules prepared by iron(II)-templated subcomponent self-assembly. Our process involved the exchange of less hydrophilic trifluoromethanesulfonate anions for hydrophilic sulfate; the resulting water-soluble cages could be rendered water-insoluble through reverse anion exchange. Notably, this strategy allowed cargoes within capsules, including polycyclic aromatic compounds and complex organic drugs, to be brought into water. Hydrophobic effects appeared to enhance binding, as many of these cargoes were not bound in non-aqueous media. Studies of the scope of this method revealed that cages containing tetratopic and tritopic ligands were more stable in water, whereas cages with ditopic ligands disassembled.     

Anion Exchange Renders Hydrophobic Capsules and Cargoes Water‐Soluble

Control over the solubility properties of container molecules is a central challenge in host–guest chemistry. Herein we present a simple anion‐exchange protocol that allows the dissolution in water of various hydrophobic metal–organic container molecules prepared by iron(II)‐templated subcomponent self‐assembly. Our process involved the exchange of less hydrophilic trifluoromethanesulfonate anions for hydrophilic sulfate; the resulting water‐soluble cages could be rendered water‐insoluble through reverse anion exchange. Notably, this strategy allowed cargoes within capsules, including polycyclic aromatic compounds and complex organic drugs, to be brought into water. Hydrophobic effects appeared to enhance binding, as many of these cargoes were not bound in non‐aqueous media. Studies of the scope of this method revealed that cages containing tetratopic and tritopic ligands were more stable in water, whereas cages with ditopic ligands disassembled.     

Future prospects in organometallic chemisty of the Main Group metals: small molecules — supramolecular chemistry

Bulky alkyl ligands functionalised with N-donor groups of the type 2-C(SiMe₃)₂(6-R-2-pyridyl), R = H or Me, stabilise unusual bonding configurations, and lead into geminal bimetallic complexes, including the formation of a tetrametallic zinc cluster. This chemistry is poised for major advances in mixed metal complexes of the Main Group metals and beyond. Magnesium(anthracene)(THF)₃ and related complexes solve the ‘missing link’ in Grignard-reagent formation with the ability to routinely prepare Grignard reagents of benzylic halides. Future directions on the use of reactive metals in synthesis will adopt the principles of green chemistry, for example in the indium(0)-promoted reactions of organic halides with various functional groups in water. Supramolecular chemistry of o-carboranes in association with ‘rigid’ container and saddle-shape molecules has led to new classes of inclusion complexes of varying stoichiometry, and extension of this work into materials of higher complexity, with other carboranes and larger globular molecules, and with functionalised container molecules is a realisation.     

Direct analysis of powder samples using transversely excited atmospheric CO<Subscript>2</Subscript> laser-induced gas plasma at 1 atm

A novel method for the direct and sensitive analysis of powder samples has been developed by utilizing the characteristics of a transversely excited atmospheric (TEA) CO₂ laser. In this study, a powder sample was placed in a container and covered by a metal mesh; the metal mesh functions to control the blowing-off of the powder. The container was then perpendicularly attached on a metal surface. When a TEA CO₂ laser (1.5 J, 200 ns) was focused on the metal surface, a large hemispherical gas plasma (radius of around 8 mm) with long emission lifetime (several tens of microseconds) was produced without ablating the metal surface. The high-speed expansion force of the gas plasma samples the powder covered by the metal mesh and fine powder particles are sent into the gas plasma region to be dissociated and excited. Sensitive semi-quantitative analysis was made on organic powder samples such as powdered rice, starch, seaweed (agar), and supplements. The detection limit of heavy metals of Cr in powdered mineral supplement was approximately 0.55 mg/kg.     

Application of microwave dielectric loss heating effects for the rapid and convenient synthesis of organometallic compounds

Diolefin-rhodium(I) and -iridium(I) complexes have been synthesised in a sealed Teflon container by use of microwave heating. The products are obtained in excellent yields and in less than 1 minute compared with many hours by conventional reflux techniques. Furthermore, the sandwich cation [Rh(η-C₅H₅)₂]⁺ can be obtained directly from RhCl₃·χH₂O and C₅H₆ by this new technique.     

Dye-sensitized solar cells based on bisindolylmaleimide derivatives

Three organic dyes based on bisindolylmaleimide derivatives (I1, I2 and I3) were synthesized and investigated as sensitizers for the application in nanocrystalline TiO₂ solar cells. The indole group, maleimide group and carboxylic group functioned as electron donor, acceptor and anchoring group, respectively. Solar-to-electrical energy conversion efficiencies under simulated amplitude-modulated 1.5 irradiation (100 mW·cm⁻²) of 2.07% were obtained for solar cells based on I2 and of 1.87% and 1.50% for I3 and I1, respectively. The open circuit voltage V _oc was demonstrated to be enhanced by the introduction of dodecyl or benzyl moieties on the indole groups. The nonplanar structure of bisindolylmaleimide was proven to be effective in aggregation resistance. This work suggests that organic sensitizers with maleimide as electron acceptor are promising candidates as organic sensitizers in dye-sensitized solar cells.     

Resin capsules: permeable containers for parallel/combinatorial solid-phase organic synthesis

A resin capsule is a permeable container for resin beads designed for multiple/combinatorial solid-phase organic synthesis. Resin capsules consist of a high density polyethylene ring sealed with peek mesh on both sides. The cylindrical shape of resin capsules enabled space-saving packing into plastic columnlike reaction vessels commonly used for solid-phase organic synthesis. Resin capsules have been evaluated for their use in combinatorial synthesis, and a set of model compounds with excellent purity was prepared.     

Three-component electrosynthesis of spirooxindole-pyran derivatives through a simple and efficient method

An eco-friendly and highly efficient process has been applied to synthesize spirooxindole-pyran derivatives in a one-pot container via a three-component reaction of isatins, malononitrile, and an enolizable C H-activated compound of diethyl 3-oxopentanedioate under constant current in n-propanol under a temperature of 50°C. The proposed method shows high yields through green reaction conditions along with other significant advantages. Among which stand out applying clean electrons as a reproducible source of energy instead of an organic catalyst, using an environmentally friendly solvent for instance propanol, a multicomponent reaction with mild condition happening in a one-pot container, and no chromatographic separation.     

A solid phase microextraction method to fingerprint dissolved organic carbon released from Eucalyptus camaldulensis (Dehnh.) (River Red Gum) leaves

A solid phase microextraction-gas chromatography (SPME-GC) method was developed to trace natural sources of dissolved organic carbon (DOC) in river systems. The effects of extraction time, temperature, salt concentration, rate of stirring, and silanisation of sampling container were examined. The optimum extraction conditions using a polydimethylsiloxane (PDMS) SPME fibre were found to be extraction for 15 min at 40 °C, pH 2, from a saturated NaCl matrix with rapid stirring in a non-silanised vial. The method gave good results for a series of six compounds representative of those likely to be present in dissolved organic carbon leached from River Red Gum leaves—cineole, terpineol, thymol, myristic acid, methyl palmitate and methyl stearate. Artificial dissolved organic carbon solutions prepared from River Red Gum leaf leachate were also examined and the effects of filtering and storage on the filtrate were noted. The method was demonstrated to have potential to track the leachate in aquatic environment, indicated by the large number of compounds extracted from leachate solutions, and the broad linear working ranges of extracted compounds.     

Leakage of gaseous 125I from a Na125I solution through a plastic film

Leakage of gaseous 125I from the various kinds of plastic film bags packing Na125I solution was determined. The polyethylene bag was permeable to the gaseous 125I and active charcoal could not prevent the leakage. The laminated plastic bags composed of polyethylene terephthalate and polyethylene was slightly permeable, and the leakage decreased either in the presence of active charcoal or with the use of doubly packed bags. Leakage of 125I from the various kinds of container for the Na125I solution was also determined.     

Quantification of Stereochemical Communication in Metal–Organic Assemblies

The derivation and application of a statistical mechanical model to quantify stereochemical communication in metal–organic assemblies is reported. The factors affecting the stereochemical communication within and between the metal stereocenters of the assemblies were experimentally studied by optical spectroscopy and analyzed in terms of a free energy penalty per “incorrect” amine enantiomer incorporated, and a free energy of coupling between stereocenters. These intra‐ and inter‐vertex coupling constants are used to track the degree of stereochemical communication across a range of metal–organic assemblies (employing different ligands, peripheral amines, and metals); temperature‐dependent equilibria between diastereomeric cages are also quantified. The model thus provides a unified understanding of the factors that shape the chirotopic void spaces enclosed by metal–organic container molecules.     

SnS-quantum dot solar cells using novel TiC counter electrode and organic redox couples

Low-cost quantum-dot sensitized solar cells (QDSSCs) were fabricated by using the earth-abundant element SnS quantum dot, novel TiC counter electrodes, and the organic disulfide/thiolate (T(2)/T(-)) redox couple, and reached an efficiency of 1.03?%. QDSSCs based on I(-)/I(3)(-), T(2)/T(-), and S(2-)/S(x)(2-) redox couples were assembled to study the role of the redox couples in the regeneration of sensitizers. Charge-extraction results reveal the reasons for the difference in J(SC) in three QDSSCs based on I(-)/I(3)(-), T(2)/T(-), and S(2-)/S(x)(2-) redox couples. The catalytic selectivity of TiC and Pt towards T(2)/T(-) and I(-)/I(3)(-) redox couples was investigated using Tafel polarization and electrochemical impedance analysis. These results indicated that Pt and TiC show a similar catalytic selectivity for I(-)/I(3)(-). However, TiC possesses better catalytic activity for T(2)/T(-) than for I(-)/I(3)(-). These results indicate the great potential of transition metal carbide materials and organic redox couples used in QDSSCs.     

Hybrid structures formed by lead 1,3-cyclohexanedicarboxylates

By the employment of hydrothermal methods, four lead 1,3-cyclohexanedicarboxylates with the compositions Pb(1,3-CHDC)(H(2)O), I, [(OPb(4))(2)(OH)(2)(C(2)O(4))(1,3-CHDC)(4)].H(2)O, II, Pb(2)(1,3-CHDC)(2)(H(2)O), III, and (OPb(3))(1,3-CHDC)(2), IV, have been prepared and characterized. Of these, I and II have layered structures while III and IV have three-dimensional structures. I-III are hybrid structures possessing extended inorganic connectivity in one or two-dimensions (I(n), n = 1 or 2) involving infinite Pb-O-Pb linkages along with zero or one-dimensional organic connectivity (O(m), m = 0 or 1). I contains two types of layers with different connectivities (I(1)O(1) and I(2)O(0). III is a truly 3-D hybrid compound with I(2)O(1) type connectivity. IV has three-dimensional organic connectivity (O(3)) but no inorganic connectivity (I(0)). The conformation of the CHDC anion is e,e in I-III and a,e in IV. In all these compounds, the lead atom has hemi- or holodirected coordination geometry.     

金属富勒烯[Dy@C_(82)(I)]膜的电化学研究

研究并对比了金属富勒烯Dy @C82 的主要异构体Dy @C82 (I)固体膜在有机溶剂乙腈及水溶液中的电化学性质 .在乙腈溶液中 ,Dy @C82 (I)膜的电化学行为不同于其溶于有机溶剂中的电化学行为 ,前两个还原峰与其对应的再氧化峰之间存在大的分裂 .但是 ,经过还原及再氧化后的Dy @C82 (I)膜却存在一对对称性很好的氧化及再还原峰 .解释为经过还原后的Dy @C82 (I)膜的结构有利于进一步氧化 ,而不需要结构重排 ;在水溶液中 ,Dy @C82 (I)膜的电化学行为不同于其在乙腈溶液中 ,却类似于其有机溶液在Pt电极上的电化学行为 ,出现了对称性很好的三对还原峰及一对氧化峰 .在水溶液中 ,Dy @ C82 (I)的前三价负离子及一价正离子是稳定的 .利用紫外 -可见 -近红外 (UV Vis NIR)光谱及扫描电镜 (SEM)等技术对膜的性质及表面形貌等进行了表征     

Highly Sensitive NH(3) Detection Based on Organic Field-Effect Transistors with Tris(pentafluorophenyl)borane as Receptor

We have increased organic field-effect transistor (OFET) NH(3) response using tris(pentafluorophenyl)borane (TPFB) as a receptor. OFETs with this additive could detect concentrations of 450 ppb v/v, with a limit of detection of 350 ppb, the highest sensitivity reported to date for semiconductor films; in comparison, when triphenylmethane (TPM) or triphenylborane (TFB) was used as an additive, no obvious improvement in the sensitivity was observed. These OFETs also showed considerable selectivity with respect to common organic vapors and stability toward storage. Furthermore, excellent memory of exposure was achieved by keeping the exposed devices in a sealed container stored at -30 °C, the first such capability demonstrated with OFETs.     

Inorganic–Organic Hybrid Molecular Clusters with Cu2I2 Rhomboid Dimer Core as Light-Emitting Coating Materials

Journal of Cluster Science - In this paper, a series of light-emitting copper(I) iodide inorganic–organic hybrid clusters has been synthesized, and they are 0D-Cu2I2(fmp)4 (1,...