Ruthenium recovery from acetic acid industrial effluent using chemically stable and high-performance polyethylenimine-coated polysulfone-Escherichia coli biomass composite fibers.

Recovery of precious metal ions from waste effluents is of high concern. In general, ruthenium (Ru) is used in the Cativa process as promoter for carbonylation catalyst and discharged into acetic acid effluent. In the present work, we have designed and developed polyethylenimine-coated polysulfone-bacterial biomass composite fiber (PEI-PSBF) to recover Ru from industrial effluent. The sorbent was manufactured by electrostatic attachment of polyethylenimine (PEI) to the surface of polysulfone-biomass composite fiber (PSBF), which was prepared through spinning of the mixture of polysulfone and Escherichia coli biomass in N,N-dimethylformamide (DMF) into water. Developed PEI-PSBF was highly stable in the acetic acid effluent. The maximum sorption capacity of the developed sorbent PEI-PSBF, coated with PEI (with M.W. of 75,000), was 121.28±13.15mg/g, which was much higher than those of ion exchange resins, TP214, Amberjet 4200, and M500. The PEI-PSBF could be successfully applied in the flow-through column system, showing 120 beds of breakthrough volume.

High-Performance Isocyanide Scavengers for Use in Low-Waste Purification of Olefin Metathesis Products.

Three isocyanides containing a tertiary nitrogen atom were investigated for use as small-molecule ruthenium scavenging agents in the workup of olefin metathesis reactions. The proposed compounds are odorless, easy to obtain, and highly effective in removing metal residues, sometimes bringing the metal content below 0.0015 ppm. The most successful of the tested compounds, II, performs very well, even with challenging polar products. The performance of these scavengers is compared and contrasted with other known techniques, such as silica gel filtration and the use of self-scavenging catalysts. As a result, a new hybrid purification method is devised, which gives better results than using either a self-scavenging catalyst or a scavenger alone. Additionally, isocyanide II is shown to be a deactivating (reaction quenching) agent for olefin metathesis and superior to ethyl vinyl ether.

The role of biomass in polyethylenimine-coated chitosan/bacterial biomass composite biosorbent fiber for removal of Ru from acetic acid waste solution.

The present study is aimed at understanding the role of bacterial biomass in functionalizing polyethylenimine (PEI)-coated bacterial biosorbent fiber (PBBF). To make PBBF, chitosan/biomass composite fiber was coated with PEI and then cross-linked by glutaraldehyde. The role of biomass in the fiber was investigated through sorption experiments and SEM, FTIR and XPS analyses with differently prepared fiber sorbents. In the case that the chitosan fiber was made without the biomass, it could not be coated with PEI. Meanwhile, the chitosan/biomass composite fiber could successfully coated with PEI and primary amine groups were significantly increased on the surface of the fiber. Therefore, the biomass should be essential to make PEI-reinforced chitosan fiber.

Development of a reliable analytical method for extraction spectrophotometric determination of ruthenium(III) from catalyst and fissium alloy using o-methylphenyl thiourea as a chromogenic chelating ligand.

A simple and selective method is developed for the extraction spectrophotometric determination of ruthenium(III) using o-methylphenyl thiourea (OMPT) as a chromogenic chelating ligand. The basis of the proposed method is ruthenium(III)-OMPT complex formation in aqueous hydrochloric acid media (3.0molL(-1)) after 5.0min heating on a boiling water bath and the complex formed is extracted into chloroform. The absorbance of green colored ruthenium(III)-OMPT complex is measured at 590nm against the reagent blank. Beer's law was obeyed up to 42.5µgmL(-1) of ruthenium(III) and the optimum concentration range is 7.56-39.81µgmL(-1) of ruthenium(III) as evaluated by Ringbom's plot. Molar absorptivity and Sandell's sensitivity of ruthenium(III)-OMPT complex in chloroform are 2.34×10(3)Lmol(-1) cm(-1) and 0.043µgcm(-2) respectively. The composition of ruthenium(III):OMPT complex (1:2) was established from slope ratio method, mole ratio method and Job's continuous variation method. Complex was stable for more than 48h. The interfering effect of various foreign ions was studied and suitable masking agents are used wherever necessary to enhance the selectivity of the method. Proposed method is successfully applied for determination of ruthenium(III) from binary and ternary synthetic mixtures, synthetic mixtures corresponding to fissium alloy and ruthenium catalyst. Repetition of the method was checked by finding relative standard deviation (R.S.D) for 10 determinations which was 0.23%. A scheme for sequential separation of palladium(II), ruthenium(III), rhodium(III) and platinum(IV) has been developed.

Ruthenium recovery from acetic acid waste water through sorption with bacterial biosorbent fibers.

A fibrous bacterial biosorbent was developed to bind precious metal-organic complexes in batch and column processes. Polyethylenimine (PEI)-modified bacterial biosorbent fiber (PBBF) was prepared by spinning Corynebacterium glutamicum biomass-chitosan blends, coating them with PEI and cross-linking with glutaraldehyde. When an acetic acid waste solution containing 1822.9mg/L Ru was used as a model waste solution, Ru uptake by the PBBF was 16.5 times higher than that of the commercial ion exchange resin, Lewatit MonoPlus M600. The maximum amounts of Ru uptake were 110.5, 16.0 and 6.7mg/g for PBBF, raw biomass, and Lewatit MonoPlus M600, respectively. In a flow-through packed bed, PBBF exhibited the breakthrough time of 42.32h. Therefore, PBBF can be considered as an alternative sorbent for recovery of anionic metal-organic complexes from waste solutions.

Isomer separation and gas-phase configurations of organoruthenium anticancer complexes: ion mobility mass spectrometry and modeling.

We have used ion mobility-mass spectrometry combined with molecular modeling for the separation and configurational analysis of three low-molecular-weight isomeric organoruthenium anticancer complexes containing ortho-, meta-, or para-terphenyl arene ligands. The isomers were separated using ion mobility based on traveling-wave technology and the experimentally determined collision cross sections were compared to theoretical calculations. Excellent agreement was observed between the experimentally and theoretically derived measurements.

A convenient method to remove ruthenium byproducts from olefin metathesis reactions using polymer-bound triphenylphosphine oxide (TPPO).

Ruthenium byproducts from ring-closing metathesis reactions can be removed by refluxing the crude reaction mixture with resin-bound triphenylphosphine oxide (TPPO) in toluene or by stirring with dimethyl sulfoxide (DMSO) and silica gel at room temperature. Residual levels of ruthenium can be achieved that are as low as 0.04 microg per 5 mg of product when a combination of TPPO, DMSO, and silica gel is used. The polymer-bound TPPO retained its efficiency after being recycled six times.

Synthesis and efficiency of a spherical macroporous epoxy-polyamide chelating resin for preconcentrating and separating trace noble metal ions.

The determination of noble metals in various materials usually requires their preconcentration and separation from other elements. In spite of the improvements in analytical instrumentation and the development of new analytical techniques such as ICP-MS, which are capable of detecting metal ions at ppt levels, the interference caused by the sample matrix still exists and is perhaps the most serious problem, making a pre-determination enrichment step necessary. Thus, the search for efficient preconcentration and separation methods is essential. A series of chelating resins that can selectively adsorb noble metal ions from aqueous solutions have been described. Functional groups, such as salicylaldoxime and thiosemicarbazide have been incorporated in cross-linked polymers or porous silica gel. These resins have very high selectivity for one or several types of noble metal ion. However, desorption of noble metals from these resins is usually difficult. Hence, the development of an adsorbent from which noble metals can be easily desorbed is needed. In this paper, a new spherical macroporous epoxy-polyamide chelating resin that met this requirement was synthesized by one step reaction. The synthesis of the resin was safe, rapid and more simple and economical than many report adsorbents. Meanwhile, the resin showed more advantages: better acid and alkali resistance; higher adsorption capacity and lower preconcentration concentrations. A resin column procedure combined with inductively coupled plasma atomic emission spectrometry (ICP-AES) for the determination of trace Rh(III), Ru(III) and Ir(IV) in real samples was established.

Infrared spectra of RuTPP, RuCOTPP, and Ru(CO)2TPP isolated in solid argon.

Infrared spectra of unstable species such as CO-free ruthenium tetraphenylporphyrin RuTPP and RuCOTPP (species with vacant coordination sites) isolated in solid argon at 8 K have been recorded. Selective deposition conditions allow the isolation of either RuTPP and RuCOTPP or RuCOTPP and Ru(CO)2TPP. This depends on the preparation conditions of the sample. A specific Ru-CO bending mode has been characterized at 590.1 cm(-1) for Ru(CO)2TPP. The behavior of each vibrational mode of RuTPP, RuCOTPP, and Ru(CO)2TPP has been analyzed. Modes such as gamma8 at 721.3 cm(-1) (out-of-plane stretching mode gamma(Cbeta-H)sym) and nu41 at 1342.8 cm(-1) (nuCalpha-N coupled with deltaCalpha-Cm) reflect the charge transfer in the porphyrin. Indeed, the addition of one or two CO ligands to RuTPP reduces the charge transfer between the metal center and the porphyrin, which appears as an increase in the frequency of the nu41 mode and in a decrease in that of the gamma8 mode.

Ultrafiltration membranes for the separation of catalyst and products in homogeneous catalysis systems.

Results of preliminary studies on concentration by ultrafiltration and reuse of a Ru(III)EDTA complex in homogeneous catalysis are reported. A method of preparation and selection of conditions of making cellulose acetate membranes for concentrating Ru(III)EDTA is described. At an operating pressure of 75 psig (517 kPa), the above catalyst can be concentrated to seven to eight times its initial concentration. The membrane used exhibits a separation of about 97.5% for the complex with a permeate flow rate of about 3-6 gallons per sq. ft per day. The catalyst activities were determined for two reactions, viz. hydroformylation of 1-hexene and carbonylation of ammonia for five cycles of concentration followed by reuse. The experimental data indicated that the catalyst concentration by ultrafiltration for subsequent reuse is simple and attractive and can provide potentially energy saving alternative to the cumbersome conventional separation processes associated with the recovery of catalysts in homogeneous catalysis.

[Separation of [Rh-103m]-rhodocene derivatives from the parent [103Ru]ruthenocene derivatives and their organ distribution]. / Abtrennung von [103mRh]Rhodocen-Derivaten von den analogen [103Ru]Ruthenocen-Derivaten und deren Organ-Verteilung.

The radioactive decay of [103Ru]ruthenocene derivatives leads to 103mRh labelled rhodocinium derivatives, which can be separated by the extraction of a lipophilic solution of the ruthenocen derivate with water. The separation factor 103mRh/103Ru reaches values of 32:1 Rh3+ ions are not liberated and extracted. The organ distribution of the 103mRh labelled rhodocinium derivatives gained from ruthenocene and from N-isopropyl-ruthenocene amphetamine is different from the distribution of the parent ruthenocene compound. The liver and kidney uptake of the rhodocinium-amphetamine is much higher than the uptake with ruthenocene amphetamine.

An effective electron donor to cytochrome oxidase. Purification, identification, and kinetic characterization of a contaminant of ruthenium red, hexaamineruthenium II/III.

When the calcium-transport inhibitor, ruthenium red, is chromatographed on a cation exchange resin, it yields a number of colored fractions and a colorless component that absorbs in the ultraviolet. The electron transfer activity previously ascribed to ruthenium red (Schwerzmann, K., Gazzotti, P., and Carafoli, E. (1976) Biochem. Biophys. Res. Commun. 69, 812) fractionates exclusively with the UV-absorbing material. On the basis of spectral, physical, and activity studies, we have identified this compound as Ru(NH3)62+/3+. It is shown that Ru(NH3)62+/3+ is an efficient electron donor directly to cytochrome oxidase, without mediation by cytochrome c. The steady state kinetics of electron transfer from Ru(NH3)62+ to purified oxidase resembles that of cytochrome c, showing a biphasic pattern but higher apparent Km values (Km1 = 8 microM, Km2 = 88 microM). Under conditions that favor tight binding to the oxidase, cytochrome c acts as a competitive inhibitor of Ru(NH3)62+, indicating that the two electron donors interact with cytochrome oxidase at the same site(s). The efficiency of Ru(NH3)62+ as an electron mediator to cytochrome aa3 and the similarity of its kinetic behavior to that of cytochrome c, make it a potentially valuable tool for investigating the mechanism of energy conservation in the terminal segment of the mitochondrial respiratory chain.