Metal ion extraction behavior of poly([2(methacryloyloxy)ethyl]trimethylammonium chloride-co-acrylic acid) resin

SUMMARY The crosslinked poly([2-(methacryloyloxy)ethyl]trimethyl ammonium chloride-co-acrylic acid) was tested as adsorbent for Cd(II), Hg(II), Zn(II), Pb(II), Cr(III), and U(VI) by batch equilibrium procedure. At pH 5.0 the adsorbent retained 74% (1.865 meq/g) of U(VI) with a maximum capacity of load of 2.7 meq/g (108 mg/g). The resin-U(VI) equilibrium was achieved around of 1 h which is considered adequate for a heterogeneous reaction. It showed a high selectivity for U(VI) respect to all the other metal ions both from competitive and non-competitive conditions. The recovery of the resin was over 65% by H₂SO₄ and Na₂CO₃. Received: 5 April 1999/Revised version: 14 July 1999/Accepted: 27 July 1999     

Preparation,photophysical, and electrochemical properties of three novel trinuclear Ru(II) polypyridyl complexes based on diazafluorenes

Three tripodal ligands 2,2′,2″-tris[(4,5-diazafluoren-9-ylimino)phenoxyethyl]amine (L¹), 1,3,5-tris[(4,5-diazafluoren-9-ylimino)phenoxymethyl]-2,4,6-trimethylbenzene (L²), 1,1′,1″-tris[(4,5-diazafluoren-9-ylimino)phenoxymethyl]-1″′-(p-tosyloxymethyl)-methane (L³), and corresponding Ru(II) complexes [(bpy)₆L^1–3(Ru^II)₃](PF₆)₆ (Ru-L^1–3) have been prepared. Cyclic voltammetry of the three complexes are consistent with one Ru(II)-centered quasi-reversible oxidation and three ligand-centered reductions. Photophysical behaviors are investigated by UV–Vis absorption and fluorescence spectrometry. The three complexes display metal-to-ligand charge transfer absorption at 445 nm and emission at 578 nm.     

Inverse gas chromatographic observation of thermodynamic interaction between poly (vinylidene fluoride) and organic solvents

Summary Inverse gas chromatography (IGC) has been applied to observe the interaction between poly(vinylidene fluoride) (PVDF) and organic solvent systems under conditions approaching infinite dilution of the volatile component. The specific retention volumes (V_g ⁰) were calculated from the retention volumes of the PVDF/solvent systems. The retention diagrams (RDs) which were plotted as ln V_g ⁰ vs. reciprocal temperature, corresponded with the thermodynamic behavior of PVDF. PVDF dissolves well in carbonyl-containing solvents at high temperatures. In these systems, the solution is converted easily to a thermoreversible gel by standing at room temperature. The Flory-Huggins interaction parameter (χ₁₂) and molar heat of sorption of probe absorbed by the amorphous part of PVDF (Δ H₁ ^s) calculated from the retention values indicated that the characteristics of the interaction between PVDF and the solvent (probe) varied with temperature and probe properties. The results of IGC of PVDF/solvent systems were discussed in relation to the dissolution and gelation behavior of PVDF. Received: 29 September 1999/Revised version: 30 November 1999/Accepted: 9 December 1999     

Synthesis of small molar mass perdeuterated polyethylpropylene (d-PEP) as an auxiliary for neutron studies

Summary An inert non-crystalline cryoprotectant oil was needed as a non-incoherent scattering matrix for neutron studies of solvent containing crystalline materials. This led us to prepare perdeuterated polyethylpropylene (PEP) with a molar mass around 1100 g/mol. On route to this material an improved method for the preparation of isoprene-d₈ starting from calcium carbide and acetone-d₆ was devised. Subsequent anionic polymerization using t-butyl lithium as initiator resulted in an oligomeric perdeuterated polyisoprene (PI) with an average chain length of approx. 15 monomer units and Mw/Mn: 1.1. This polymer was deuterated with D₂ and Pd/C (10%) in cyclohexane to yield the desired perdeutero polymer (PEP-d). The polymer fulfill the important properties that it does not crystallize at low temperature and has a low neutron scattering efficiency. Received: 15 September 1999/Revised version: 3 November 1999/Accepted: 3 November 1999     

Electro-optic studies on novel chiral liquid crystalline polysiloxanes with the N* phase

Summary The electro-optical response of two novel side chain liquid crystalline polysiloxane copolymers containing chiral pendant groups was investigated. It was found that both copolymers possessed N^* phase with a long pitch and therefore the origin of the electro-optical response detected in this phase was considered to be the electroclinic effect. Received: 6 November 1998/Revised version: 29 March 1999/Accepted: 30 March 1999     

Synthesis of polyurethanes containing dioxynitrostilbene as a NLO-chromophore and their properties

Summary 3,4-Di-(2'-hydroxyethoxy)-4'-nitrostilbene (2) were prepared by the reaction of 2-iodoethanol with 3,4-dihydroxy-4'-nitrostilbene (1). Diol 2 was condensed with 2,4-toluenediisocyanate and 3,3'-dimethoxy-4,4'-biphenylenediisocynate to yield polyurethanes 3 and 4 containing the NLO-chromophore 3,4-dioxy-4'-nitrostilbene. Polymers 3 and 4 were soluble in common organic solvents such as acetone and DMSO. T _g value of the resulting polymers was in the range of 109–114°C. Electrooptic coefficient (r₃₃) of the poled polymer films were in the range of 20–25 pm/V at 633 nm. Polymers 3 and 4 showed a thermal stability up to 300°C in TGA thermograms, which is acceptable for NLO device applications. Received: 29 September 1999/Revised version: 19 November 1999/Accepted: 25 November 1999     

LONG TERM MONITORING OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) IN BLUE MUSSELS (Mytilus edulis) FROM A REMOTE SCOTTISH LOCATION

Farmed mussels have been collected on a monthly basis since 1999 from a remote site on the west coast of Scotland for polycyclic aromatic hydrocarbon (PAHs) analysis with the aim of establishing background concentrations as a benchmark against which to assess any environmental incident. Total PAH (2- to 6-ring parent and alkylated) concentrations ranged from 12.5 to 151.2 μg kg^?1 wet weight. Seasonal trends were evident with concentrations being significantly higher for samples collected between November and March compared to those collected between April and October. By taking the median of medians for each of these time periods two background concentrations are suggested for the total PAH concentrations (2- to 6-ring PAHs parent and alkylated); for April to October: 31.2 μg kg^?1 wet weight and for November to March: 62.9 μg kg^?1 wet weight. Individual PAH concentrations were mainly below the OSPAR Background Assessment Concentrations (BACs), where they are specified, and were only exceeded for the heavier 4- and 5-ring PAHs (fluoranthene, pyrene, benz[a]anthracene and benzo[a]pyrene) in samples collected between November and March. Differences were also seen in the PAH profiles with season. Mussels collected between November and March had a higher proportion of the heavier PAHs compared to mussels collected in the summer and autumn.     

Addition of dichlorocarbene to cis-1,4-poly(2-trimethylsilylmethyl-1,3-butadiene)

Summary Copolymers made up of 1,4-(2,3-dichloromethylene-2-trimethylsilylmethyl-1,3-butadiene) (I) and 1,5-(3-chloro-2-methylene-pent-3-ene) (II) units have been prepared by potassium fluoride elimination of trimethylchlorosilane from cis-1,4-poly(2.3-dichloromethylene-2-trimethylsilylmethyl-1,3-butadiene) (III). III was prepared by the addition of dichlorocarbene to 1,4-poly-(2-trimethylsilylmethyl-1,3-butadiene) (cis/trans = 9/1) (IV). Polymer III was characterized by ¹h, ¹³C and ²⁹Si NMR as well as by elemental analysis. The copolymer was characterized by ¹H, ¹³C and ²⁹Si NMR spectroscopy. The ratio of I and II units in the copolymer were determined by ¹H NMR and elemental analysis.     

Preparation,spectroscopic, and electrochemical properties of four novel trinuclear Ru(II) polypyridyl complexes containing diazafluorene

Four tripodal ligands 2,2′,2″-tris[4-(4,5-diazafluoren-9-ylhydrazinyl)methylenephenoxyethyl]amine (L¹), 1,1,1-tris[4-(4,5-diazafluoren-9-ylhydrazinyl)methylenephenoxymethyl]propane (L²), 1,3,5-tris[4-(4,5-diazafluoren-9-ylhydrazinyl)methylenephenoxymethyl]-2,4,6-trimethylbenzene (L³), 1,3,5-tris[4-(4,5-diazafluoren-9-ylhydrazinyl)methylenephenoxymethyl]benzene (L⁴), and corresponding Ru(II) complexes [(bpy)₆L^1–4(Ru^II)₃](PF₆)₆ (Ru-L^1–4) have been synthesized. Cyclic voltammetry of these complexes comprise one Ru(II)-centered reversible oxidation and three ligand-centered reductions. Photophysical behaviors are investigated by UV–Vis absorption and luminescence spectrometry. These complexes display metal-to-ligand charge transfer absorption at around 410 nm and emission at around 582 nm.     

Preparation and crystal structure determination of adducts of copper(II) chloride with 3-aryl-1-(imino-pyridin-2-yl-methyl)-5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-pyrazoles

1,1,1-Trifluoro-4-methoxy-4-aryl-but-3-en-2-ones react with 2-pyridylcarboxamidrazone to produce the corresponding 1,1,1-trifluoro-4-aryl-4-(N¹-pyridine-2-carboxamidrazone)-3-buten-2-ones. The butenones react with copper(II) chloride to give 1:1 adducts, in which the donor molecules were shown to isomerize to their cyclic pyrazolic forms. The crystal structure of the 4-fluoro-phenyl derivative, dichloro-[3-(4-fluorophenyl)-1-(imino-pyridin-2-yl-methyl)-5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-pyrazole]-copper(II), was solved by X-ray crystallography. The structural results are compared with those of other copper(II) chloride adducts of similar ligands containing the amidrazone pharmacophore, which have been tested as anticancer drugs.     

Anionic synthesis of aromatic carboxyl functionalized polymers. Chain-end functionalization of poly(styryl)lithium with 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl] oxazole

The novel syntheses of 4-(4,5-dihydro-4,4-dimethyl-2-oxazolyl)benzophenone, 1-[4-(4,5-dihydro-4,4-dimethyl-2-oxazolyl)phenyl]-1-phenylethanol and 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl]oxazole ( 1 ) are described. ω-Oxazolyl polystyrene ( 2 ) was synthesized in quantitative yields by the reaction of poly(styryl)lithium with stoichiometric amounts of 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl]oxazole ( 1 ) in toluene/tetrahydrofuran (4 : 1 v/v) at −78°C. Deblocking of the oxazoline protecting group by acid hydrolysis followed by saponification quantitatively provides the corresponding aromatic carboxyl chain-end functionalized polystyrene ( 3 ). The functionalization agent and functionalized polymers were characterized by HPLC, thin layer chromatography, size exclusion chromatography, vapor phase osmometry, spectroscopy (¹H NMR, ¹³C NMR and FTIR), potentiometry and elemental analysis.     

Elimination of pyrochlore phase in high-concentration Sm3+-doped PMN-PT piezoelectric ceramics by excessive MgO

Undesirable pyrochlore phase often appears in Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ (PMN-PT)-based ceramics with high rare-earth ion (RE³⁺) doping concentration, which greatly limits their development. In this study, 0–5 mol% Sm³⁺-doped Pb(Mg_1/3Nb_2/3)O₃-29PbTiO₃ (PMN-29PT:0-5Sm) ceramics were first synthesized using traditional precursor method. In the X-ray diffraction spectra and scanning electron microscope images of PMN-29PT:3-5Sm ceramics, the diffraction peaks of pyrochlore phase and pyrochlore grains with octahedral morphology were observed, respectively. The reason for the appearance of the pyrochlore phase is that Sm³⁺ doping causes the Nb-rich regions. To eliminate the pyrochlore phase, PMN-29PT:3-5Sm ceramics were resynthesized by an improved precursor method in which an excess of 4 mol% MgO was added to the reactants before pre-sintering. After adding an excess of 4 mol% MgO, the concentration ratio of Nb⁵⁺ and Mg²⁺ in the pyrochlore grains returned to the value in the perovskite grains, and the pyrochlore phase was transformed into the perovskite phase PMN. The dielectric, ferroelectric, and electromechanical properties were compared before and after eliminating the pyrochlore phase. The results show that the comprehensive performance of the ceramics is improved after eliminating the pyrochlore phase.     

Spiroheterocyclic system. Part IV: Novel azo dye sulpha drugs of spiroheterocyclic naphthenes

Novel azo-dyes have been synthesized by diazotization of 4-amino benzene-4′-(substituted heterocyclo) sulphonamide derivatives and coupling with 1-oxa-4-thia-spiro[4,4]nonan-2-one (I) and/or with l-oxa-4-thia-spiro[4,5]decan-2-one (I′) in acid medium to give the corresponding 3-azo-(4′-substituted benzenesulphonamido)-l-oxa-4-thia-spiro[4,4]nonan-2-one (II-IX) and/or l-oxa-4-thia-spiro[4,5]decan-2-one (II′-IX′] as spiro-ligands. Treatment of these ligands with metal salts of iron (Fe³⁺), copper (Cu²⁺) and mercury (Hg²⁺) as chlorides in ethanolic solution furnished the corresponding metal chelates (II_a-c-IX_a-c) and/or (II′_a-c-IX′_a-c). The compounds were tested in vitro for antimicrobial activity to study the structure-activity relationship.     

A sensing behavior synergistic liquid–liquid extraction and spectrophotometric determination of nickel(II) by using 1-(2ˊ,4ˊ-dinitro aminophenyl)-4,4,6-trimethyl-1,4-dihydropyrimidine-2-thiol: Analysis of foundry and electroless nickel plating waste water

We report the sensing behavior of liquid–liquid extraction of nickel(II), which has been selectively determined from contaminated water samples by a simple UV-visible spectrophotometer. The method is based on synergistic extraction of nickel(II) by 1-(2ˊ,4ˊ-dinitro aminophenyl)-4,4,6-trimethyl-1,4-dihydropyrimidine-2-thiol [2ˊ,4ˊ-dinitro APTPT] with pyridine. Nickel(II) reacts with 2ˊ,4ˊ-dinitro APTPT and forms a green-colored complex at pH 9.2. In addition, the Ni(II) ions were detected with the naked eye with the ligand. The absorbance of the coloured complex was measured at 660 nm and the colored complex is stable for more than 48 h even in the presence of other competing ions. The system obeyed Beer’s law in the concentration range of 5–50 μg mL^?1 of nickel(II) and the optimum range evaluated by Ringbom’s plot method is 10–40 μg mL^?1 with an excellent linearity and a correlation coefficient of 0.999. The molar absorptivity and Sandell’s sensitivity of the extractive species were found to be 1.64 × 10³ dm³ mol^?1 cm^?1 and 0.0585 μg cm^?2 in the presence of pyridine, and 7.4 × 10² dm³ mol^?1 cm^?1 and 0.78 μg cm^?2 in the absence of pyridine, respectively. The composition of nickel(II)-2ˊ,4ˊ-dinitro APTPT-pyridine was established by the slope ratio method, the mole ratio method and Job’s method of continuous variation. It was found that the metal:ligand:synergent (M:L:Sy) ratio is 1:2:2. To assess the precision and accuracy of the developed method, determinations were carried out at n = 5. The relative standard deviation of all measurements does not exceed 0.16%. Excellent selectivity was found towards the Ni(II) ion due to a specific complex formation between the Ni(II) ion and the organic ligand. In the extraction of Ni(II), several affecting factors, including the solution pH, ligand concentration, equilibrium time, initial Ni(II) ion concentration and foreign ions, were investigated and the applicability of the method was checked by the analysis of synthetic mixtures and alloys. The developed method was successfully used for the determination of nickel(II) from waste water effluents from the foundry region and the nickel plating industry (Kolhapur city). The results obtained by the developed method were also confirmed by AAS. We claimed from this study that Ni(II) could be successfully determined by the spectrophotometric method developed in the current work. The present work is obviously much simpler than the conventional method comprising multistep processes.     

Synthesis,Thermal Decomposition,and Properties of [Mn(CHZ)3][C(NO2)3]2

A new coordination compound, [Mn(CHZ)₃][C(NO₂)₃]₂, was synthesized and characterized by elemental analysis, IR and UV spectra, and its crystal structure was determined by X‐ray single crystal diffraction. The crystal belongs to the triclinic system and space group with a=0.88737(18) nm, b=1.1804(2) nm, c=1.1936(2) nm, β=83.73(3)°, V=1.1121(4) nm³, Z=2, D_c=1.867 g cm⁻³. Every Mn(II) ion is six‐coordinated to three CHZ molecules through three carbonyl oxygen atoms and three terminal nitrogen atoms to form a distorted octahedral structure. Mn(II) ions, carbohydrazide ligand molecules, and trinitromethanide anions are jointed to a complicated three‐dimensional netted structure through coordination bonds, electrostatic forces, and extensive hydrogen bonds. The thermal decomposition character and mechanism was studied by DSC, TG‐DTG, and FTIR techniques. The non‐isothermal kinetics has also been studied on the exothermic decomposition by using Kissinger's method and Ozawa–Doyle's method. In addition, the impact, friction, and flame sensitivity data were determined. All properties data observed show that the title complex has high energy, good thermal stability, and moderately friction sensitivity.     

Coupling and linking reactions of living polyisobutylene by allylsilanes

The reactions of living polyisobutylene (PIB⁺) with different allylsilanes, as potential linking and coupling agents, have been studied. Quantitative monoaddition of 2-Phenylallyltrimethylsilane to living PIB⁺ yielded macromonomer (I), however coupling was absent. Rapid and quantitative coupling has been observed with 1,3-bis[2-(3-trimethylsilyl)-propenyl]benzene (bTPB). Using 1-(2-propenyl)-3-[2-(3-trimethylsilyl)-propenyl]benzene (PTPB) star polymers with an average of four arms have been prepared with high efficiency. The study of this linking reaction revealed that star formation takes place in two well separated steps. In the first step a macromonomer is formed in situ by the rapid reaction of PIB⁺ with the allyltrimethylsilyl functionality. Subsequent reaction of this macromonomer with the remaining electrophilic PIB⁺ ends followed by interchain reactions results in the formation of star polymers. Received: 16 May 1999/Revised version: 1 September 1999/Accepted: 1 September 1999     

Nitriles in heterocyclic synthesis. Part III: New sulpha drugs related to cyanopyridine derivatives

4-Hydroxyacetophenone (1) was reacted with cinnamonitrile derivatives (2–6) to give 3-cyano-4-(substituted phenyl)-6-(p-hydroxyphenyl)-pyridines (7–11). Interaction of compounds 7–9 with 4-substituted heterocyclo-benzenesulphonyl diazoniura chloride gave the corresponding 3-cyano-4-(sub-stituted phenyl)-6-(3′-azobenzene sulphonamido-4′-hydroxyphenyl) pyridines (12–29). The corresponding iron (III) copper (II) and mercury (II) chelates were also prepared in a 1:2 metal-to-ligand ratio. All the synthesized compounds were characterized on the basis of microanalysis, IR and ¹H-NMR spectrometry.     

Study of the polymerization of 1-octadecene with different rnetallocene catalysts

Summary 1-Octadecene (C18) was polymerized by using different metallocene catalysts. The rac-Et(Ind)₂ZrC1₂/MAO (I) and rac-Me₂Si(Ind)₂ZrC1₂/MAO (III) presented the highest activity as compared with ra-Et(2-Me-Ind)₂ZrCl₂/MAO (II) and Ph₂C(Flu)(Cp)ZrC1₂/MAO (IV) catalysts. Catalyst IV produced polymers with highest molecular weights. The microstructure of the polymers was determined by ¹³C-NMR spectroscopy. Catalyst systems I, II and III produced isotactic polymers while catalyst IV produced polymers with mainly syndiotactic structures but with large amount of stereoregular error. Received: 21 June 2002/Revised version: 4 November 2002/ Accepted: 4 November 2002     

A 3D Porous Coordination Polymer from Tetrazole Ligand and Cd(II): Crystal Structure,Luminescent Property and Adsorption of Methanol and Water

An unusual tetrazole-based Cd(II) coordination polymer, [Cd(4-tzba)(H₂O)]_n (tzba = 4-(tetrazolyl)benzenecarboxylic acid) (1), was synthesized by hydrothermal reaction and structurally characterized by single-crystal X-ray diffraction. The structure of 1 contains distorted octahedral cadmium centers coordinated by four different tzba^2? ligands and a water molecule. All the tzba^2? ligands display coordination of type, μ4-κN1:κN3:κN4:κO1, O2, which connects four Cd(II) atoms to form an intricate 3-D network. There are three kinds of apertures in the structure of 1; two helical channels and a hexagonal aperture are observed along different axes. Polymer 1 exhibits selective gas adsorption behavior for methanol, ethanol and water. In addition, 1 shows blue photoluminescence mainly arising from intraligand transitions of the aromatic rings in the tbza^2? ligand.