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Pyrophyllite, an aluminum silicate mineral, was used as a raw material for the production of aluminoborosilicate glass. For the application of pyrophyllite to the glass manufacturing process as a r...

Superplasticizers (cement concrete water reducers) are applied to improve the flowability of calcium-rich, alkali-activated materials, with inconsistent results. However, superplasticizer applications are limited in metakaolin-based geopolymers. The possibility of using polycarboxylate superplasticizers and methyl isobutyl carbinol (MIBC) to ameliorate the flowability of metakaolin-based geopolymers was investigated. The ratio of metakaolin, fumed silica, NaOH or KOH, and water in geopolymers at a Na2O or K2O:Al2O3:SiO2:H2O ratio = 1:1:4:10 or 1:1:4:11 was maintained in the formulations. In this study, ether- or ester-based polycarboxylate superplasticizers did not improve the workability of fresh metakaolin-based Na-geopolymers. A low MIBC dose (0.5 wt.% of metakaolin) improved the flowability by 19% and additionally increased the 7-day compressive strength by 22% from 68 to 83 MPa for plain Na-geopolymers. The entrained fine froths produced by adding MIBC during mixing likely reduced friction between metakaolin particles, and the slurry became more workable. Hence, the geopolymer mixture with an improved flowability became more homogenous, which ensured more extensive metakaolin dissolution and hydrolysis. A low MIBC dose could be effective for Na-geopolymers with dual benefits of improved workability and enhanced compressive strength.

Nickel laterite ore is classified into two principal ore types: saprolite (silicate ore) and limonite (oxide ore). Saprolite-type ore characterized by high magnesia and silica contents is treated by pyrometallurgy process. On the other hand, limonite-type ore is subjected to hydrometallurgy process to produce nickel products. Hydrometallurgy process requires that a raw material to meet the demands that Si+Mg contents lower than 10% and Fe content over than 40%. It is therefore required that separation of saprilite-type ore to use nickel laterite ore as a raw material for hydrometallurgy process. In this study, separation of sparolite-type ore and limonite-type ore from nickel laterite ore from New Caledonia has been tried by dry classification. The results show that -5 mm size fraction and +5 mm size fraction of the nickel laterite ore contains mainly limonite-type ore and saprolite-type ore, respectively. To understand the moisture content of the raw ore on the dry classification, nickel laterite ore with different moisture contents of 23.0% and 9.1% were subjected to the dry classification. The results show that drying of the ore makes the separation more efficient as the amount of the fine product, that can be subjected to hydrometallurgy process without further separation or drying operations, was increased.

In this study, the flotation behavior of malachite was investigated using hydrophobic talc nanoparticles (TNs) as collectors. To improve the floatability of TN-deposited malachite, various experimental parameters were systematically investigated. We found that the floatability sharply increased as the size of the TNs decreased. The floatability of malachite was enhanced in the presence of smaller TNs, since higher amounts of smaller TNs were deposited on the surface of the malachite, thus rendering the surface more hydrophobic. Moreover, the floatability of the TN-deposited malachite increased as the pH decreased, likely due to the more favorable interaction between TNs and malachite by means of electrostatic attraction. Furthermore, the floatability became more enhanced as the TN concentration increased, likely associated with increases in the amount of TNs deposited on the surface of the malachite, thus enhancing the floatability by altering the hydrophobicity of the surface. Our findings suggest that the application of natural hydrophobic TNs as collectors in malachite flotation should be introduced as a new concept.

In the title compound, each CoII ion is coordinated by two pyridine N atoms from two individual dipyridyl ligands, two methanol O atoms and two chloride anions in an elongated octa­hedral geometry. Each dipyridyl ligand links two CoII ions, forming infinite zigzag chains., Reaction of bis­(pyridin-3-ylmeth­yl)sulfane (L) with cobalt(II) chloride in methanol led to the formation of the title coordination polymer, [CoCl2(C12H12N2S)(CH3OH)2]n, in which the CoII cation lies on a crystallographic inversion centre and the S atom of the L ligand lies on a twofold rotation axis. Each CoII ion is coordinated by two pyridine N atoms from two bridging L ligands, two O atoms from methanol mol­ecules and two chloride anions, all inversion-related. The complex unit has an elongated octa­hedral geometry, in which N2O2 donor atoms occupy the equatorial positions and two chloride anions occupy the axial positions. Each L ligand links two CoII ions, forming an infinite zigzag chain propagating along the c-axis direction and further stabilized by O—H⋯Cl hydrogen bonds between the methanol mol­ecules and the chloride anions. Adjacent chains in the structure are connected by inter­molecular C—H⋯Cl hydrogen bonds, resulting in the formation of a three-dimensional supra­molecular architecture.

Needle-shaped aragonite, a thermodynamically metastable polymorph of CaCO3, was synthesized in a deinked old newspaper pulp (ONP) slurry, otherwise known as the in-situ aragonite formation process, in order to improve the optical properties such as the brightness and ERIC value (effective residual ink concentration) as well as to preserve the strength properties such as the breaking length of the resultant handsheet. The brightness and ERIC value of the handsheet obtained from pulp that was subjected to the in-situ aragonite formation process was improved by 20.4% (from 56.8 to 68.4%) and 55.4% (from 292.1 to 130.4ppm), respectively, relative to a raw ONP sample. The effects of the in-situ aragonite formation process on the resultant handsheet were compared with the results obtained from a similar process in which rhombohedraltype calcite was synthesized instead of the needle-shaped aragonite. From the comparison, it can be concluded that the in-situ aragonite formation process provides better optical and strength properties to the resultant handsheet than that of calcite, and this is attributed to the needleshaped morphology of aragonite. [doi:10.2320/matertrans.M2013369]

A process to produce pure calcite-type calcium carbonate by the carbonation of air-cooled blast furnace slag (BFS), which is a waste material and which has been utilized in limited applications, is reported here. The process is composed of two reactions. First, calcium ions are extracted from an air-cooled BFS slurry under pressurized gaseous CO2 (1 to 5 MPa) at 273 K, at which the extracted calcium ions and calcium carbonate formed during the extraction process are dissolved in the solution due to the high solubility of the calcium carbonate under the high pressure of CO2. The second reaction is the precipitation of pure calcite-type calcium carbonate at atmospheric pressure at the same temperature after the removal of the solid residue remaining after the extraction process. Gaseous CO2 was fed at atmospheric pressure to increase the precipitation ratio of calcium carbonate by the carbonation of the unreacted calcium ions in the solution. In this study, the influences of the following parameters on the ...

Municipal solid waste is being produced in large quantities, in keeping with a dramatic population increase and the growth of industrialization. Most of this waste is sent to landfills in South Korea. However, current treatment methods including incineration and recycling is limited owing to insufficient landfill space and the generation of leachates and soil contamination. Generally, 250–300 kg of bottom ash and 30–50 kg of fly ash are generated from one ton of incinerated municipal solid waste. This study seeks to determine the degree of influence of several main factors, such as the optimum temperature, solid-to-water ratio and CO2 concentration, on the process of accelerated carbonation of the bottom ash. The results show that the carbonation rate was at its highest at a temperature of 20°C, a solid-to-liquid ratio of 0.2 and with 20% CO2. This implies that the CO2 gas emitted from incinerators can be used directly as part of an accelerated carbonation process of bottom ash, as the water content of ra...

Stepwise synthesis and structural characterization of one-dimensional coordination polymers whose topologies depend on the anions are reported. A simple ladder-type precursor, {[Ag2(L)2](ClO4)2}n (1), was prepared by the reaction of bis(4-pyridylmethyl)sulfide (L) with AgClO4. Treatment of 1 with potassium thiocyanate and potassium cyanide afforded a twisted ribbon-type chain of type [Ag(L)SCN]n (2) and a triple-rail ladder of type [Ag3(L)2(CN)3]n (3), respectively. The result demonstrates that replacement of the noncoordinated perchlorate anions by pseudohalide ions in the coordination sphere of 1 plays a crucial role in determining the structures of the resulting species.

A new synthetic approach to prepare flexible porous coordination polymers (PCPs) by the use of soft secondary building units (SBUs) which can undergo multiple reversible metal-ligand bonds breaking is reported. We have prepared a zinc paddle-wheel-based two-fold interpenetrated PCP, {[Zn(2)(tp)(2)(L(2))]·2.5DMF·0.5water}(n) (2a, H(2)tp = terephthanlic acid; L(2) = 2,3-difluoro-1,4-bis(4-pyridyl)benzene), showing dynamic structural transformations upon the removal and rebinding of guest molecules. The X-ray structures at different degrees of desolvation indicate the highly flexible nature of the framework. The framework deformations involve slippage of the layers and movement of the two interpenetrated frameworks with respect to each other. Interestingly, the coordination geometry of a zinc paddle-wheel unit (one of the popular SBUs) is considerably changed by bond breaking between zinc and oxygen atoms during the drying process. Two zinc atoms in the dried form 2d reside in a distorted tetrahedral geometry. Compound 2d has no void volume and favors the uptake of O(2) over Ar and N(2) at 77 K. The O(2) and Ar adsorption isotherms of 2d show gate-opening-type adsorption behaviors corroborating the structure determination. The CO(2) adsorption isotherm at 195 K exhibits multiple steps originating from the flexibility of the framework. The structural transformations of the zinc clusters in the framework upon sorption of guest molecules are also characterized by Raman spectroscopy in which the characteristic bands corresponding to ν(sym)(COO(-)) vibration were used.

Stepwise synthesis and structural characterization of two-dimensional (2-D) coordination polymer frameworks with positive charged or neutral cavities are reported. First, reactions of bis(4-pyridylmethyl)sulfide (L) with silver salts (1: nitrate and 2: perchlorate) afforded the respective double-stranded one-dimensional (1-D) chains [Ag(L)NO3]n (1) and {[Ag2(L)2](ClO4)2}n (2), both of which are stabilized by face-to-face π−π interactions. In this case, the silver(I) center in the nitrato complex 1 shows four-coordinated distorted tetrahedral geometry, whereas that of the perchlorato complex 2 exhibits a distorted trigonal planar geometry. The difference of these structures indicates that the coordination ability of the anions has important effects on the silver(I) coordination environments. Interestingly, the perchlorato 1-D complex 2 allows further reactions with bridging ligands such as 4,4′-bipyridine (bpy) and terephthalate (tp2−) to give a 2-D positive-charged network {[Ag2(L)2(bpy)]·(ClO4)2·C6H6}n (...

A comparative investigation of the coordination behaviour of the 17-membered, N3O2-donor macrocycle, 1,12,15-triaza-3,4:9,10-dibenzo-5,8-dioxacycloheptadecane, L, with the soft metal ions Ag(I), Cd(II), Hg(II), and Pd(II) is reported. The X-ray structures of 12 complexes have been determined and a range of structural types, including both mononuclear and dinuclear species, shown to occur. In particular cases the effect of anion variation on the resulting structures has been investigated; L reacts with AgX (X = NO3, ClO4, PF6, OTf and CN) to yield related 2:2 (metal:ligand) complexes of types [Ag2L2(NO3)2] (1), [Ag2L2](ClO4)2 · 2DMF (2), [Ag2L2](PF6)2 · 2DMF (3), [Ag2L2](OTf)2 (4) and [Ag2L2(μ-CN)][Ag(CN)2] · H2O (5). In all five complexes the ether oxygens of each ring are unbound. In 1–4 the macrocycles are present in sandwich-like arrangements that shield the dinuclear silver centres, with each silver bonded to two nitrogen donors from one L and one nitrogen from a second L. A Ag···Ag contact is present between each metal centre such that both centres can be described as showing distorted tetrahedral geometries. In the case of 5 a rare single μ2-κC:κC symmetrically bridging two-electron-donating cyano bridge links silver ions [Ag···Ag distance, 2.7437(10) A]; the macrocyclic ligands are orientated away from the dinuclear metal centres. In contrast to the behaviour of silver, reaction of cadmium(II) perchlorate with L resulted in a mononuclear sandwich-like complex of type [CdL2](ClO4)2 · CH3CN (6). Again, the ether oxygens do not coordinate, with each L binding to the cadmium centre only via its three nitrogen donors in a facial arrangement such that a distorted octahedral coordination geometry is attained. Reaction of L with HgX2 (X = ClO4, SCN and I) yielded the monomeric species [HgL(ClO4)2] (7), [HgL(SCN)2]·CH3CN (8) and [Hg2L2](HgI4)2 · 2L (9), in which all five donors of L are bound to the respective mercury centres. However, reaction of L with Hg(NO3)2 in dichloromethane/methanol gave a mononuclear sandwich-like complex [HgL2](NO3)2 · 2CH3OH (10) without anion coordination. Reaction of K2PdCl4 and Pd(NO3)2 with L yielded the 1:1 complexes [PdLCl]Cl · H2O (11) and [PdL(NO3)]NO3 · CH3OH (12), respectively, in which the metal is bound to three nitrogen donors from L along with the corresponding chloride or nitrate anion. Each palladium adopts a distorted square-planar coordination geometry; once again the ether oxygens are not coordinated.

Two novel sulfur-containing amidecrownophanes, 3a (N2S) and 3b (N2S2), were synthesized by diacyl chloride–diamine sulfide coupling reactions followed by the tandem Claisen rearrangement of macrocycles 2a and 2b as precursors, respectively. The reactivity of the titled macrocycles with some transition and heavy metal ions was examined. The most salient feature of the reactions is the mercurated dihydrobenzofuran 4 derived from 3b and Hg(OAc)2. The X-ray crystal structures of 4 as well as 2a and 2b were revealed.

Amidecrownophane-type macrocycles with different number of hydroxy groups were prepared in quantitative yields by control of the conditions of thermal reaction with the aim to examine the role of hydroxy groups in anion recognition. It was proved that the hydroxy group played a critical role in anion binding for this type of macrocycles and the anion binding affinity could be tuned by different number of hydroxy groups. Further exploration clarified the presence of intramolecular hydrogen-bonding and exhibited the major effect on their anion binding potential.

Crystals of C.I. Disperse Yellow 3, an aminoazobenzene derivative, were grown in an acetonitrile solution and its crystal structure was determined by single crystal X-ray diffraction analysis. It was found that the asymmetric unit consisted of two dye molecules (A and B) and one acetonitrile solvent. In each dye molecule, the aminoazobenzene framework was almost planar due to intramolecular H-bonds. The dye molecules are connected by weak intermolecular H-bonds to form a molecular pair in “head-to-tail” mode. The acetonitrile molecule is also bound to the dye molecule by H-bonding. In the packed structure, interlayer association occurs by further π–π stacking of the molecular pairs formed. Results from thermogravimetric analysis and X-ray powder diffraction studies of a crystalline sample of the title compound support the contribution of the solvent molecule to the formation of the crystal lattice.

Two 20-membered penta- and hexadentate macrocycles containing one or two pyridine subunits, namely [20]aneNO2S2 (L1) and [20]aneN2O2S2 (L2), have been synthesized. Reaction of L1 with silver(I) nitrate afforded a unique 2:2 (M:L) disilver(I) complex [μ2-Ag2(L1)2](NO3)2 (1) in which two four-coordinate Ag atoms bridge two ligands to form a cyclic dimer. In contrast, an endo-dentate 1:1 monosilver(I) complexes [AgL2]X; [X = ClO4 (2) or PF6 (3)] which show isomorphous structures were obtained from the reactions of L2 with silver(I) salts.

A new dicadmium(II) complex [Cd2(L)2(H2O)2](NO3)4 · 8H2O (1) with the tripodal amide ligand L (tris[3-aza-2-oxo-4-(2-pyridyl)butyl]amine) was synthesized and structurally characterized. Complex 1 is revealed as a dinuclear 2:2 (Cd:L) complex, in which each cadmium(II) ion is hepta-coordinated with the coordination surrounding of distorted monocapped octahedral geometry. Two cadmium(II) ions are dibridged by two carbonyl μ-O atoms forming a Cd2(μ-O)2 parallelogram-type moiety. Interestingly, the dinuclear coordination sphere can be seen as resulting from the fusion of two distorted monocapped octahedral [Cd(L)(H2O)]2+ units through sharing one edge originated from the two carbonyl μ-O atoms as a first example. Comparative NMR, IR and FAB-mass data of 1 are also discussed.

A 21-membered O 4 S 2 -donor-macrocycle ( L ) incorporating a dibenzo-subunit was synthesized. From the reaction of L with AgPF 6 , an endo -type 1:1 complex [Ag L ]PF 6 ( 1 ) was obtained. On complexation, the conformation of L changes dramatically due to metal–ligand coordination as well as π-interactions between the metal and the dibenzo-subunit from L . This unique change in configuration showing a twist-and-squeeze type process illustrates how large flexible ligands stabilize complexes through conformational changes.

A heterogeneous “naked-eye” colorimetric and spectrophotometric cation sensor, SNT-1, was prepared by immobilization of the azo-coupled macrocyclic receptor 1 on a silica nanotube (SNT) via sol–gel reaction. The optical sensing ability of SNT-1 was studied by addition of metal ions such as Ag+, Co2+, Cd2+, Pb2+, Zn2+, Fe3+, Cu2+, and Hg2+ (all as nitrates) in water. Upon the addition of Hg2+ in suspension SNT-1 resulted in a color change from yellow to violet. This is novel rare example for chromogenic sensing of a specific metal ion by inorganic nanotubes. On the other hand, no significant changes in color were observed in the parallel experiments with Co2+, Cd2+, Pb2+, Zn2+, Fe3+, Cu2+, and Ag+. These findings confirm that SNT-1 can be useful as chemosensors for selective detection of Hg2+ over a range of metal ions. More interestingly, after addition of NO3– and ClO4– SNT-1 was observed to change color from yellow to violet and pink, respectively. However, no color changes were observed upon addition of Cl–, Br–, I–, SCN–, or SO42–. Furthermore, the extraction ability of SNT-1 was also estimated by measuring the amount of Hg2+ adsorbed by ion chromatography, showing that 95 % of the Hg2+ ion is extracted by SNT-1. This suggests that SNT-1 is potentially useful as a stationary phase for the separation of Hg2+ in liquid chromatography. In order to extend the above performance to a portable chemosensor kit, SNT-1 was coated as a thin film of 50 μm thickness onto a glass substrate. The supported SNT-1 also changed from yellow to violet when dipped into Hg2+ solution. On the other hand, no significant change in color was observed in other metal-ion solutions. The results imply that the supported SNT-1 is applicable as a portable colorimetric sensor for detection of Hg2+ in the field.

Aims: Enhancement of algicidal activity by immobilization of algicidal bacteria antagonistic to Stephanodiscus hantzschii. Methods and Results: In laboratory studies, A diatom-lysing bacterium, Pseudomonas fluorescens HYK0210-SK09 showed strong algicidal activity against S. hantzschii, but a natural mesocosm study revealed that this bacterium failed to fully control natural blooms of Stephanodiscus at the low water temperatures that favour these blooms. Here, we sought to develop an effective immobilization strategy for enhancing the algicidal activity of HYK0210-SK09 in the natural setting. Bacterium HYK0210-SK09 was immobilized with various carriers including agar, alginate, polyurethane and cellulose sponge. The bacterial cells immobilized with cellulose sponge (CIS) induced more rapid and complete lysis of S. hantzschii than other carriers, and had a higher packing ability than polyurethane. Furthermore, CIS-immobilized cells showed higher lysis of S. hantzschii at the same concentrations as that of free cells (≤1 × 107 cells ml−1), and had especially strong algicidal activity at the low temperatures (

Depending on the solvents used for crystallization, silver nitrate and the flexible dithioether-type ligand incorporating piperazine diamide [L: 1,4-bis((cyclohexylthio)acetyl)piperazine] readily formed two distinct types of 2D (1) and 3D (2) coordination polymers with identical formula [Ag2(NO3)2L]n. The preparation and structural characterisation of 1 and 2 are reported as an example for the supramolecular isomerism.

From the reaction of tribenzo-S2O2 macrocyclic ligand (L1) and silver picrate (AgPic), a unique binuclear complex [Ag2(L1)2(Pic)2] (1) has been obtained. The species 1 has been characterised by single-crystal X-ray diffraction analysis providing a definitive proof of its cyclic dimer structure as well as the anion–ligand π–π stacking interactions between L1 and Pic−. The result of a comparative NMR experiment suggests that the solid structure of 1 is also retained in solution.

[reaction: see text] Calix[4]thiacrowns with hetero-L(1) and a homodonor set (L(2)) were synthesized and characterized by X-ray analysis. From the reaction of L(2) with AgPF(6), disilver complex [Ag(2)(L(2))](PF(6))(2) (1) was isolated. By comparing 1,3-alternate conformations of L(2) and 1, we found a considerable decrease of dihedral angles of two opposite aromatic rings upon complexation. This finding can be explained in terms of the "chopsticks process", which illustrates how Ag(+)-arene pi-coordination occurs. Heterobinuclear complexation of L(1) in solution was also observed.

In this case, the particular product formeddepends on a delicate balance between alternative confor-mations of the organic ligands and on the nature of themetals and anions as well as solvent molecules employed.Topologically, an angular bidentate ligand can form a dis-crete dimer, a 1D chain, and an infinite loop-chain, etc.

Self-assembly of the dipodal ligand L and CdX 2 (X = ClO 4 and NO 3 ) produced unique pseudo-cyclic complexes (A) [Cd(L)(H 2 O)(CH 3 OH)](ClO 4 ) 2 ( 1 ) and [Cd(L)(H 2 O)(NO 3 )](NO 3 ) ( 2 ), respectively. From the stepwise reaction of the pseudo-cyclic complexes (A) followed by coligands (B) such as 4,4′-bipyridine and terephthalate, the controlled one-dimensional coordination polymer {[Cd(L)(H 2 O)(bpy)](ClO 4 ) 2 (MeOH) 0.5 } n ( 3 ) with (A–B) n array and the discrete “dumbbell”-like complex [Cd 2 (L) 2 (tp)(H 2 O) 2 ](tp)(H 2 O) 9 ( 4 ) with (A–B–A) patterns were isolated.

Serendipitous synthesis of 2-amino-2,3-dihydrobenzofuran derivatives 4a–g was achieved starting from the Baylis–Hillman adducts. In the reaction sequence, intramolecular oxygen atom transfer from nitrogen atom to arene moiety was observed.

S 2 O-donor macrocyclic isomers incorporating a xylyl group in o- (L 1 ), m- (L 2 ) and p-positions (L 3 ) extract no metal ions except silver(I) from aqueous to chloroform phase. And the magnitudes of %Ex for silver(I) are in the order of L 1 > L 2 > L 3 . Taking this result into account, L 1 -L 3 were utilized as membrane active components to prepare potentiometric silver(I)-selective electrodes. The proposed macrocycles-based electrodes El (L 1 ), E2 (L 2 ) and E3 (L 3 ) exhibited comparable results which show considerable selectivity toward silver(I) over alkali, alkali earth and other transition metal ions. Comparative NMR study on L 1 -L 3 and their complexes with silver(I) in solution was also accomplished. In addition, a unique sandwich-type complex [Ag(L 1 ) 2 ]ClO 4 was prepared from the assembly reaction of L 1 with AgClO 4 and structurally characterized by an X-ray diffraction analysis.

Research on tripodal complexes has grown in recent decades and has been subject of numerous reports.1-11 The reasons for this interest include their relevance to model functions of metalloenzymes1-3 and their potential applications in catalysis.13-17 The ligand system used most in this category has been tren, the tripodal tetraamine N(CH2CH2NH2)3, and its derivatives.4 The bz3tren is a versatile tetradentate ligand, known to form stable complexes not only with transition metals5-11 including Cu2+, Zn2+ and Co2+ but also anion species.12 However, only few results on the d10 metal complexes with bz3tren have been reported by us10 and others.6,7 As a part of on going efforts, we therefore focus our attention to extend other d10 system that includes heavy metal ions.

Isomeric series ofdilinked NO 2 S 2 macrocycles (L 2 : para-, L 3 : meta- and L 4 : ortho-linked) capable ofbinuclear complexing ability were prepared from its monomeric analog L 1 in reasonable yields except ortho-type reaction, which led to mixture due to the formation of monomer-type macrocyclic quaternary ammonium bromide L 5 . Moreover, L 2 (as 2HNO 3 form) and L 5 were confirmed by an X-ray crystallography. Reaction of HgCl 2 with L 2 yielded a binuclear complex [Hg 2 (L 2 )Cl 4 ]. In the complex, each mercury(II) has a distorted tetrahedral environment made up of S and N donors from an exodentate L 2 and two coordinated Cl atoms.

S2Ox macrocyclic ligands with (L1: x = 3 and L2: x = 4) and without (L3: x = 3 and L4: x = 4) dibenzo-subunit were employed as extractants to clarify the anion–ligand interaction on the extraction efficiency of soft metal picrates. All of the ligands shows silver(I) selectivity and the silver picrate was more extractable with L1 and L2 when compared with L3 and L4. From the X-ray and NMR data, the enhanced extractability for the silver picrate by L1 and L2 was revealed due to the additional stabilization of the complexes, [Ag(L)picrate], by anion–ligand π–π interaction between the picrate ion and one benzo-subunit in the ligand. Such anion–ligand interaction would give a valuable hint for the molecular design of new extractants for the soft metal ions including silver(I).

Assembly reaction of L2 (5,8-dioxa-2,11-dithia[12]-m-cyclophane) with K2PtCl4 afforded a unique cyclic dimer complex [Pt2(L2)2Cl4] (1) but its whole conformation is disordered except two metal centers. Recrystallization of the same compound from dichloromethane afforded an isostructural product [Pt2(L2)2Cl4]CH2Cl2 (2) but without such disorder. In 2, each Pt atom is four-coordinated in a square-planar environment with two S atoms from different two L2s and to two Cl− ions in a cis arrangement showing a basket-like conformation. Very interestingly, one dichloromethane molecule found in the cyclic dimmer cavity stabilizes the whole structure of 2 by hydrogen bonds.

Heavy metal complexations with host molecules have been received much attention, not only because of prime environmental concern, but also the heavy metal binding is one of fundamental problems of molecular recognition. Based on the optimal requirement of cooperative effect of the mixed coordinating sites via thiaoxa donor set for heavy metals, we have reported the solvent extraction, membrane transport and crystal structures of Ag and Pd complexes with the new system of the cyclic and acyclic ionophores incorporating a potential thiaoxa donor system. Particularly, the acyclic thiaoxa ionophores can be obtained simply and cheaply because there is no need for expensive and timeconsuming steps, such as high dilution or template methods, which is usually required in preparations of cyclic analogues. In the continuing work on the metal complexation, we were recently able to prepare the new Hg complex of the S2O2 dipodal ligand L and have determined its X-ray crystal structure. Although the stability constant for the Hg complex with L is not yet available, this result is enough to motivate the works on the stripping voltammetry by using the modified carbon paste electrode (CPE) as a more sophisticated detection procedure for Hg. Herein, we describe the preparation of the Hg complex of L together with its crystal structure. In addition, the characteristics of the L-modified CPEs are presented in terms of the Hg detection.

We prepared a brand-new, bowl-shaped molecular architecture in one step from the reaction of ninhydrin and phloroglucinol in acetic acid in excellent yield (95%) in a one-pot reaction and the bipolarofacial nature of this compound was confirmed by its X-ray structure.

Novel S4O n mixed donor macrocycles (1, n=1; 2, n=2) were synthesized by the coupling reactions of corresponding dichlorides with dithiols under high dilution conditions. Synthesis and crystal structures of Tl+ and Ag+ complexes, [Tl(2)+ and Ag(2)+], with macrocycle 2 are described. The electrode based on macrocycle 2 showed excellent potentiometric sensing ability for Tl+ and Ag+ ions. This remarkable sensing of the proposed electrode can be understood in terms of the synergy effect of a soft–soft acid–base interaction and π-coordination, especially for the Tl+ ion, which was observed from the crystal structure of the corresponding complex.

The interaction of cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), silver(I) and lead(II) with symmetrical mono-N-benzylated and xylyl-linked macrocyclic ligands derived from the O2N3-macrocycle, 1,12,15-triaza-3,4:9,10-dibenzo-5,8-dioxacycloheptadecane, has been investigated. The log K values for the respective 1 : 1 complexes in 95% methanol (I= 0.1; Et4NClO4, 25 degrees C) of the mono-benzylated derivative have been determined potentiometrically and the results compared with the values obtained previously for the parent (non-benzylated) ring system as well as for related di- and tri-benzylated macrocyclic species. Mono-benzylation results in slightly enhanced stability for the 1 : 1 silver(I) complex while the values for the corresponding complexes of the other six ions are in each case decreased even though the highest stability is still maintained for the 1 : 1 copper(II) complex. The log K results are in accord with a previous proposal that N-benzylation of amine-containing macrocyclic rings of the present type will normally have only a minor (positive or negative) influence on the affinity towards silver(I) while the corresponding binding strengths towards the remaining six metal ions are significantly reduced-behaviour we term 'selective detuning'. Competitive seven-metal transport experiments across a bulk chloroform membrane have been performed using both ligand systems as ionophores. In parallel to the log K results, transport selectivity for copper(II) was exhibited by both systems, with similar transport efficiencies being evident when compared on a 'per macrocyclic cavity' basis.

A series of benzyl, 2-picolyl, 3-picolyl armed tetrahomodioxacalix[4]arene tetraamideswith four p-phenyl groups on the upper rim were synthesized. They were found to be in the C-1,2-alternate conformation by 1H, 13C NMR, andX-ray crystal structure.The nitrogen atom of the 2-picolyl group played an important role in the metal ion complexation.

The reactions of O3S2-macrocycle L with K2PtCl4 afforded mono- (1) or dinuclear (2) complexes depending on the solvent used. From the X-ray crystal structures, it is confirmed that one water molecule stabilizes the diplatinum complex 2 via hydrogen bond.

Amide-linked tripyridine derivative 1 and its dipyridine analogue 2 as a reference were synthesized, and their self-assembled behaviors were characterized at different pH values. Surprisingly, 1 was gelated in water and emitted strong blue color, whereas 2 was not gelated in any solvent and emitted no fluorescence. The unique gelation capability of 1 is attributed to the cooperative effects of π−π stacking and intermolecular hydrogen bonding interactions.

Calix[4]bis(thiacrown-5) (L) with 1,3-alternating conformation was employed as a strong dinucleating ligand for the soft metal ions AgI and CuI. The reaction of L with AgPF6 afforded a discrete endo-coordinated disilver(I) complex 1, [Ag2L](PF6)2. In contrast, mixed products (2a + 2b) consisting of 3D networks were obtained from the reaction of L and CuI; 2b linked with a Cu4I4 cubane unit was shown to generate photoluminescence, while 2a linked with a Cu2I2 rhomboid unit does not.

An isomeric series of S 2 O macrocycles incorporating a xylyl group at the ortho (L1), meta (L 2 ), and para (L 3 ) positions were employed to examine the influence of the ring rigidity on silver(I) coordination modes in resulting supramolecular complexes (1-3); L1 and L 3 afforded sandwich (1; Ag:L1 = 1:2) and infinite 1-D (3) complexes, respectively; otherwise, L 2 gave the 1-D polymer (2a), 2:3 club sandwich (2b), and unique 2:4 bridged dinuclear complex (2c) complexes, in which their topologies vary with the solvent used.

A two-dimensional square-grid-shaped coordination polymer incorporating the dithiaoxa macrocycle (1), [Cu(1)CN]n (2), has been prepared by a self-assembly process involving the interaction of 1 with CuCN; the parallel reaction of 1 with CuI afforded the one-dimensional double-stranded coordination polymer [Cu(1)I]n (3).

(λ = 0.71073 A) radiation sourceand a CCD detector at 173(2) K. The 45 frames of twodimensional diffraction images were collected and processedto obtain the cell parameters and orientation matrix. The first50 frames were retaken after complete data collection. Thecrystal showed no significant decay and no correction wasapplied for absorption or decay. The frame data wereprocessed to give structure factors, using the programSAINT.

The crystals with high quality forX-ray analysis were obtained by the vapor diffusion ofdiethyl ether into the DMSO solution of the precipitates.Crystal parameters and procedural information correspond-ing to data collection and structure refinements are given inTable 1. The geometric parameters of the complex are shownin Table 2.According to X-ray crystal structure analysis (Figure 1),the discrete cyclodimeric complex, [Ag(1)]

This study investigates a possibility of synthesizing calcium carbonate following the process of extracting calcium ion (Ca) from air-cooled blast furnace slag by using pure CO2 gas at various pressures and extraction agents. At first, Ca ion Source from air-cooled blast furnace slag was firstly extracted at CO2 pressure and using acids and ammonium solutions. And then, we compared extraction rate CO2 pressure and various solutions. Finally, we performed calcium carbonate synthesis using aqueous CO2 and extracted Ca ion by the CO2 pressure, acetic acid. Following the process, calcium carbonate was effectively synthesized by the reaction between extracted Ca and CO3, a form of dissolved CO2. We expect that this study could demonstrate a possibility of conversing the slag and CO2 from the steel industry into high value added product, Calcium carbonate.

The title compound, tri­aqua(1,10-phenanthroline-2,9-di­car­box­yl­ato)­magnesium(II) dihydrate, [Mg(PDA)(H2O)3]·2H2O, (H2PDA is 1,10-phenanthroline-2,9-di­carboxyl­ic acid, C14H8N2O4) has twofold crystallographic symmetry. The Mg atom is in a distorted pentagonal bipyramidal coordination environment with two N atoms and two O atoms from PDA and one O atom from a water mol­ecule forming the pentagonal plane, and two O atoms from two water mol­ecules occupying axial positions. The crystal structure comprises an infinite two-dimensional network of hydrogen-bonded mol­ecules.

Reaction of the O(2)S(2)X-macrocycles (L(1), X = S; L(2), X = NH; and L(3), X = O) with Cu(ClO(4))(2) x 6 H(2)O affords 1:1 (M/L) square-pyramidal Cu(II) complexes when X = S and NH but yields a rare 1:2 sandwich-type tetrahedral Cu(I) complex when X = O; the X-ray structures of all three complexes are reported. Substitution of O for S or NH in the ligand structure thus results in a donor-set-induced II/I oxidation state change of the copper, and this is accompanied by a square-pyramidal to tetrahedral topological change in the solid state. Spectrophotometric titration data (including Job plots) indicate that similar behavior occurs in acetonitrile. In further experiments aimed at investigating the generality of the above redox behavior, it was shown that the 16- and 18-membered analogs of the 17-membered L(3) also induce a similar II/I redox change in acetonitrile. It was demonstrated for L(3) that the above-induced Cu(II/I) change is also maintained when the reaction solvent is changed from acetonitrile to methanol or ethanol.