Extraction of Rh(III) from hydrochloric acid by protonated NTAamide(C6) and analogous compounds and understanding of extraction equilibria by using UV spectroscopy and DFT calculations.

Extraction of Rh from hydrochloric acid is conducted using NTAamide(C6) (N,N,N´,N´,N´´,N´´-hexahexyl-nitrilotriacetamide) and other related compounds. We use the ion-pair extraction of anionic species of Rh-chloride and protonated extractant. Rh ions exist as Rh(Cl)n(H2O)6-n (n ≤ 5) and the tertiary nitrogen atom in an extractant are protonated to produce a quaternary amine in acidic condition. The D(Rh) values are changeable because the Rh-Cl-H2O complex forms from + 3 to - 2 valency. Rh-chloride ion with a peak of spectrum at 504 nm can be extracted effectively, where RhCl4(H2O)- and RhCl5(H2O)2- exist from Density functional theory calculation and UV spectrum. The maximum distribution ratio (D) of Rh(III) is 16, and 85 mM Rh can be extracted from 1 M HCl dissolving 96 mM, due to less third phase formation. Approximate 80% of Rh can be stripped by the water-soluble reagents having the activities of neutralization and solvation. The figure for the Graphical Index saved in the JPEG, PNG or TIFF format at 300 dpi should be pasted with the size adjusted to the frame below (5 cm long and 8 cm wide).

Spherulitic Crystallization in Langmuir-Blodgett Films of the Ditetradecyldimethylammonium-Au(dmit)2 Salt.

Spherulitic crystallization in Langmuir-Blodgett (LB) films of the ditetradecyldimethylammonium-Au(dmit)2 [2C14N+Me2-Au(dmit)2] salt has been characterized by polarized light microscopy, Fourier-transform infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD) analyses. Analyses by differential scanning calorimetry (DSC) for the bulk crystals indicate that annealing in the temperature range of 58-100 °C may be appropriate to improve the order in the LB film. The polarized light microscopy measurement further revealed that a spherulite structure was formed after the film was annealed at 80 °C for 60 min. FT-IR spectroscopy measurements demonstrated that the order of the principal hydrocarbon chains was improved and that the rotation of CH3 groups was hindered by the annealing. Out-of-plane XRD analyses revealed that the d-spacing of the 2C14N+Me2-Au(dmit)2 LB film changed from 3.1 to 2.5 nm upon annealing. We hypothesize that a layered structure with interdigitated hydrocarbon chains, which is equivalent to or close to that of the corresponding bulk crystal, has been realized in the LB film by annealing. We consider that two different kinds of one-dimensional (1D) interactions along the a-axis are the driving forces to realize the spherulite structure in the LB system; one is an extended 1D contact due to the pronounced interdigitation of the alkyl chains of the ammonium ion, which plays a role similar to that of the folding of chains in the lamellar structures of polymers, and the other is a 1D extended sulfur-sulfur contact between Au(dmit)2 dimer pairs. So far, spherulite formation in LB films has been reported almost exclusively for polymerized materials. Here, we demonstrate that a spherulite texture can also be formed in LB films based on nonpolymerized materials via the interdigitation of hydrocarbon chains, leading to a new well-ordered state.

Correction: PEG-nanotube liquid crystals as templates for construction of surfactant-free gold nanorods.

Correction for 'PEG-nanotube liquid crystals as templates for construction of surfactant-free gold nanorods' by Naohiro Kameta et al., Chem. Commun., 2018, 54, 4665-4668.

PEG-nanotube liquid crystals as templates for construction of surfactant-free gold nanorods.

Lyotropic liquid crystals, in which nanotubes coated with polyethylene glycol were aligned side-by-side in aqueous dispersions, acted as templates for the construction of surfactant-free gold nanorods with controllable diameters, functionalizable surfaces, and tunable optical properties.

A simple biofuel cell cathode with human red blood cells as electrocatalysts for oxygen reduction reaction.

A red blood cell (RBC) from human exhibited direct electron transfer (DET) activity on a bare indium tin oxide (ITO) electrode. A formal potential of -0.152 V vs. a silver-silver chloride saturated potassium chloride (Ag|AgCl|KCl(satd.)) was estimated for the human RBC (type AB) from a pair of redox peaks at around 0.089 and -0.215 V (vs. Ag|AgCl|KCl(satd.)) on cyclic voltammetric (CV) measurements in a phosphate buffered saline (PBS; 39 mM; pH 7.4) solution. The results agreed well with those of a redox couple for iron-bearing heme groups in hemoglobin molecules (HbFe(II)/HbFe(III)) on the bare ITO electrodes, indicated that DET active species were hemoglobin (Hb) molecules encapsulated by a phospholipid bilayer membrane of the human RBC. The quantity of electrochemically active Hb in the human RBC was estimated to be 30 pmol cm(-2). In addition, the human RBC exhibited oxygen reduction reaction (ORR) activity in the dioxygen (O2) saturated PBS solution at the negative potential from ca. -0.15 V (vs. Ag|AgCl|KCl(satd.)). A single cell test proved that a biofuel cell (BFC) with an O2|RBC|ITO cathode showed the open-circuit voltage (OCV) of ca. 0.43 V and the maximum power density of ca. 0.68 µW cm(-2).

Mechanism of selective oxygen reduction on platinum by 2,2'-bipyridine in the presence of methanol.

Mechanism of selective oxygen reduction on platinum by 2,2'-bipyridine in the presence of methanol has been investigated by in situ surface-enhanced infrared absorption spectroscopy. The addition of 2,2'-bipyridine caused the decrease of adsorbed water molecules and those existing near the surface of platinum. The formation of both CO and formate, the latter being the intermediate in the non-CO path for methanol oxidation, depressed in the presence of 2,2'-bipyridine, suggests that 2,2'-bipyridine hinders methanol oxidation via both non-CO and CO paths on platinum. The geometrical effect of 2,2'-bipyridine adsorbed onto platinum was also investigated by multisite Monte Carlo simulation. It is indicated that selective oxygen reduction is caused by the difference in the number of required adsorption sites between methanol and dioxygen molecules. The suppression of Pt oxide species by 2,2'-bipyridine is found to be another factor that enhances the oxygen reduction.

New CO tolerant electro-catalysts exceeding Pt-Ru for the anode of fuel cells.

Novel types of CO tolerant electro-catalysts from Pt and organic metal complexes that are far superior to Pt-Ru and practically usable as anode catalysts in reformate gas fuel cells with 100 ppm CO tolerance have been developed.