Multiwalled Carbon Nanotubes Encased in Ruthenium Oxide Film as a Hybrid Material for Neurotransmitters Sensor

A hybrid film (MWCNTs‐RuO_x?nH₂O) which contains multiwalled carbon nanotubes (MWCNTs) along with the incorporation of ruthenium oxide (RuO_x?nH₂O) has been synthesized on glassy carbon electrode (GCE), gold (Au), indium tin oxide (ITO) and screen printed carbon electrode (SPCE) by potentiostatic methods. The presence of MWCNTs in the hybrid film enhances surface coverage concentration (Γ) of RuO_x?nH₂O to ≈2100%. The surface morphology of the hybrid film deposited on ITO has been studied using scanning electron microscopy and atomic force microscopy. These two techniques reveal that the RuO_x?nH₂O incorporated on MWCNTs. Electrochemical quartz crystal microbalance study too reveals the incorporation of MWCNTs and RuO_x?nH₂O. The MWCNTs‐RuO_x?nH₂O hybrid film exhibits promising enhanced electrocatalytic activity towards the biochemical compounds such as epinephrine and norepinephrine. The electrocatalytic responses of these analytes at RuO_x?nH₂O, MWCNTs and MWCNTs‐RuO_x?nH₂O hybrid films have been measured using cyclic voltammetry. The obtained sensitivity values from electrocatalysis studies of analytes for MWCNTs‐RuO_x?nH₂O hybrid film are higher than the RuO_x?nH₂O and MWCNTs films. Finally, the flow injection analysis has been used for the amperometric studies of analytes at MWCNTs‐RuO_x?nH₂O hybrid film modified SPCEs.     

High-performance supercapacitors of hydrous ruthenium oxide/mesoporous carbon composites

The amorphous hydrous ruthenium oxide/mesoporous carbon composites (denoted as RuO₂·xH₂O/MC), obtained by loading small amount of amorphous hydrous ruthenium oxide nanoparticles ranged from 0.9 to 5.4% by weight of Ru (denoted as RuO₂·xH₂O) on mesoporous carbon (MC), were investigated for the first time and were used for supercapacitors. Electrochemical measurements showed that RuO₂·xH₂O/MC composites not only have an enhanced specific capacitance but also retain the superior rate capability of MC. The RuO₂·xH₂O/MC composite with Ru loading of 3.6 wt% exhibited an increase of the specific capacitance of approximately 57% (from 115 to 181 F/g) at the scan rate of 25 mV s⁻¹ in 0.1 M H₂SO₄ aqueous electrolyte. The specific capacitance based on the mass of RuO₂ was estimated to be 1,527 F/g, by subtracting the contribution from MC in the composite. Cycle performance tests for RuO₂·xH₂O/MC composite (3.6 wt% Ru) showed that approximately 2.8% loss of the total capacitance was observed after 1,000 cycles.     

Anodic composite deposition of RuO2·xH2O–TiO2 for electrochemical supercapacitors

This communication demonstrates the first work on anodic composite deposition of oxide nanocomposites. Rutile TiO₂ nanoflowers with an average petal size of ca. 10 nm in diameter and 100 nm in length were synthesized from a TiCl₃ solution purged with air at 25 °C for 12 days prior to the composite deposition. Hydrous ruthenium oxide (RuO₂·xH₂O) and TiO₂ nanoflowers were composite-deposited onto Ti substrates for supercapacitors. In comparing with RuO₂·xH₂O deposits, RuO₂·xH₂O–TiO₂ nanocomposites with a highly porous nature exhibit the weakly mass-dependent specific capacitance and high-power capacitive characteristics.     

Electrodeposition of Three‐Dimensional Porous Platinum Film on Removable Polyaniline Template for High‐Performance Electroanalysis

Three‐dimensional porous platinum (Pt_por) films are prepared based on Pt electrodeposition on polyaniline (PANI) modified electrodes followed by selective dissolution of PANI with HNO₃. Electrochemical quartz crystal microbalance data suggest that the PANI‐H₂PtCl₆ interaction involves redox and coordination reactions, depending on the working potential. The Pt_por shows better electrocatalytic performance than the Pt/PANI and conventionally electrodeposited Pt. The Pt_por modified glassy carbon electrode (GCE) can electrocatalyze the oxidation of H₂O₂ with a sensitivity of 414 µA cm^?2 mM^?1 and a detection limit of 9 nM, and the chitosan‐glucose oxidase/Pt_por/GCE can sense glucose with a sensitivity of 93.4 µA cm^?2 mM^?1.     

EQCM Study of Ru and RuO2 Surface Electrochemistry

The present study represents comparative analysis of voltammetric and microgravimetric behavior of active ruthenium (Ru), electrochemically passivated ruthenium (Ru/RuO₂) and thermally formed RuO₂ electrodes in the solutions of 0.5 M H₂SO₄ and 0.1 M KOH. It has been found that cycling the potential of active Ru electrode within E ranges 0 V–0.8 V and 0 V–1.2 V in 0.5 M H₂SO₄ and 0.1 M KOH solutions, respectively, leads to continuous electrode mass increase, while mass changes observed in alkaline medium are considerably smaller than those in acidic one. Microgravimetric response of active Ru electrode in 0.5 M H₂SO₄ within 0.2 V–0.8 V has revealed reversible character of anodic and cathodic processes. The experimentally found anodic mass gain and cathodic mass loss within 0.2–0.8 V make 2.2–2.7 g F^?1, instead of 17 g F^?1, which is the theoretically predicted value for Ru(OH)₃ formation according to equation: Ru+3H₂O?Ru(OH)₃+3H⁺+3e^?. In the case of Ru/RuO₂ electrode relatively small changes in mass have been found to accompany the anodic and cathodic processes within E range between 0.4 V and 1.2 V in the solution of 0.5 M H₂SO₄. Meanwhile cycling the potential of thermally formed RuO₂ electrode under the same conditions has lead to continuous decrease in electrode mass, which has been attributed to irreversible dehydration of RuO₂ layer. On the basis of microgravimetric and voltammetric study as well as the coulometric analysis of the results conclusions are presented regarding the nature of surface processes taking place on Ru and RuO₂ electrodes.     

Gadolinium(III)‐Hydroxy Ladders Trapped in Succinate Frameworks with Optimized Magnetocaloric Effect

Two kinds of inorganic gadolinium(III)‐hydroxy “ladders”, [2×n] and [3×n], were successfully trapped in succinate (suc) coordination polymers, [Gd₂(OH)₂(suc)₂(H₂O)]_n ? 2n H₂O ( 1 ) and [Gd₆(OH)₈(suc)₅(H₂O)₂]_n ? 4n H₂O ( 2 ), respectively. Such coordination polymers could be regarded as alternating inorganic–organic hybrid materials with relatively high density. Magnetic and heat capacity studies reveal a large cryogenic magnetocaloric effect (MCE) in both compounds, namely (ΔH=70 kG) 42.8 J kg^?1 K^?1 for complex 1 and 48.0 J kg^?1 K^?1 for complex 2 . The effect of the high density is evident, which gives very large volumetric MCEs up to 120 and 144 mJ cm^?3 K^?1 for complexes 1 and 2 , respectively.     

Ligand‐to‐Ligand Charge‐Transfer Transitions of Platinum(II) Complexes with Arylacetylide Ligands with Different Chain Lengths: Spectroscopic Characterization,Effect of Molecular Conformations,and Density Functional Theory Calculations

The complexes [Pt(tBu₃tpy){C?C(C₆H₄C?C)_n?1R}]⁺ (n=1: R=alkyl and aryl (Ar); n=1–3: R=phenyl (Ph) or Ph‐N(CH₃)₂‐4; n=1 and 2, R=Ph‐NH₂‐4; tBu₃tpy=4,4’,4’’‐tri‐tert‐butyl‐2,2’:6’,2’’‐terpyridine) and [Pt(Cl₃tpy)(C?CR)]⁺ (R=tert‐butyl (tBu), Ph, 9,9’‐dibutylfluorene, 9,9’‐dibutyl‐7‐dimethyl‐amine‐fluorene; Cl₃tpy=4,4’,4’’‐trichloro‐2,2’:6’,2’’‐terpyridine) were prepared. The effects of substituent(s) on the terpyridine (tpy) and acetylide ligands and chain length of arylacetylide ligands on the absorption and emission spectra were examined. Resonance Raman (RR) spectra of [Pt(tBu₃tpy)(C?CR)]⁺ (R=n‐butyl, Ph, and C₆H₄‐OCH₃‐4) obtained in acetonitrile at 298 K reveal that the structural distortion of the C?C bond in the electronic excited state obtained by 502.9 nm excitation is substantially larger than that obtained by 416 nm excitation. Density functional theory (DFT) and time‐dependent DFT (TDDFT) calculations on [Pt(H₃tpy)(C?CR)]⁺ (R= n‐propyl (nPr), 2‐pyridyl (Py)), [Pt(H₃tpy){C?C(C₆H₄C?C)_n?1Ph}]⁺ (n=1–3), and [Pt(H₃tpy){C?C(C₆H₄C?C)_n?1C₆H₄‐N(CH₃)₂‐4}]⁺/+H⁺ (n=1–3; H₃tpy=nonsubstituted terpyridine) at two different conformations were performed, namely, with the phenyl rings of the arylacetylide ligands coplanar (“cop”) with and perpendicular (“per”) to the H₃tpy ligand. Combining the experimental data and calculated results, the two lowest energy absorption peak maxima, λ₁ and λ₂, of [Pt(Y₃tpy)(C?CR)]⁺ (Y=tBu or Cl, R=aryl) are attributed to ¹[π(C?CR)→π*(Y₃tpy)] in the “cop” conformation and mixed ¹[d_π(Pt)→π*(Y₃tpy)]/¹[π(C?CR)→π*(Y₃tpy)] transitions in the “per” conformation. The lowest energy absorption peak λ₁ for [Pt(tBu₃tpy){C?C(C₆H₄C?C)_n?1C₆H₄‐H‐4}]⁺ (n=1–3) shows a redshift with increasing chain length. However, for [Pt(tBu₃tpy){C?C(C6H4C?C)_n?1C₆H₄‐N(CH₃)₂‐4}]⁺ (n=1–3), λ₁ shows a blueshift with increasing chain length n, but shows a redshift after the addition of acid. The emissions of [Pt(Y₃tpy)(C?CR)]⁺ (Y=tBu or Cl) at 524–642 nm measured in dichloromethane at 298 K are assigned to the ³[π(C?CAr)→π*(Y₃tpy)] excited states and mixed ³[d_π(Pt)→π*(Y₃tpy)]/³[π(C?C)→π*(Y₃tpy)] excited states for R=aryl and alkyl groups, respectively. [Pt(tBu₃tpy){C?C(C₆H₄C?C)_n?1C₆H₄‐N(CH₃)₂‐4}]⁺ (n=1 and 2) are nonemissive, and this is attributed to the small energy gap between the singlet ground state (S₀) and the lowest triplet excited state (T₁).     

Synthesis,characterization and properties of polyaniline doped with transition metal substituted silicotungstate

Polyaniline hybrid material doped with transition metal mono-substituted silicotungstate β₂-K₆[SiW₁₁M(H₂O)O₃₉]?·?xH₂O (M?=?Mn²⁺, Co²⁺, Cu²⁺, Fe²⁺) were prepared for the first time. Their scanning electron microscopy (SEM), infrared (IR), UV–Vis, and X-ray diffraction (XRD) patterns confirm the existence of Keggin anions and form the space reticular structure. The material exhibits excellent proton conduction, its proton conductivity is 9?×?10^?2?s?cm^?1 at room temperature (20°C).     

Supramolecular networks constructed by cationic copper(II) complexes incorporating hybrid water–anionic polymeric assemblies

Two complexes, [Cu₂(TFSA)(2,2′-bpy)₄]?·?TFSA?·?8H₂O (1) and {[Cu(4,4′-bpy)(H₂O)₂]?·?TFSA?·?6H₂O} _n (2) (H₂TFSA?=?tetrafluorosuccinic acid, 2,2′-bpy?=?2,2′-bipyridine, and 4,4′-bpy?=?4,4′-bipyridine), have been synthesized and structurally characterized by X-ray structural analyses. Complex 1 is a binuclear molecule bridged by TFSA ligands; 2 is a 1-D chain bridged by 4,4′-bpy ligands. The asymmetric units of the two complexes are composed of cationic complexes [Cu₂(TFSA)(2,2′-bpy)₄]²⁺ (1) and [Cu(4,4′-bpy)(H₂O)₂]²⁺ (2), free TFSA anion, and independent crystallization water molecules. A unique 2-D hybrid water–TFSA anionic layer by linkage of {[(H₂O)₈(TFSA)]^2?} _n fragments consisting of 1-D T6(0)A2 water tape and TFSA anionic units by hydrogen bonds in 1 was observed. Unique 2-D hybrid water–TFSA anionic layer generated by the linkage of {[(H₂O)₆(TFSA)]^2?} _n fragments consisting of cyclic water tetramers with appended water molecules and TFSA anionic units, and 1-D metal–water tape [Cu–H₂O?···?(H₂O)₆?···?H₂O^?] _n in 2 were found. 3-D supramolecular networks of the two complexes consist of cationic complexes and water–TFSA anionic assemblies connected by hydrogen bonds.     

Pt Nanoparticle‐modified Carbon Fiber Microelectrode for Selective Electrochemical Sensing of Hydrogen Peroxide

We report a simple approach to the production of carbon fiber‐based amperometric microbiosensors for selective detection of hydrogen peroxide (H₂O₂), which was achieved by electrometallization of carbon fiber microelectrodes (CFMs) by electrodeposition of Pt nanoparticles. The Pt‐carbon hybrid sensing interface provided a sensitivity of 7711±587 μA ? mM^?1 ? cm^?2, a detection limit of 0.53±0.16 μM (S/N=3), a linear range of 0.8 μM–8.6 mM, and a response time of <2 sec. The morphologies of the Pt nanoparticle‐modified CFMs were characterized by scanning electron microscopy. To achieve selectivity, permseletive layers, polyphenylenediamine (PPD) and Nafion, were deposited resulting in exclusion of the anionic and cationic interferents, ascorbic acid and dopamine, respectively, at their physiologically relevant concentrations. The resultant sensors displayed a sensitivity to hydrogen peroxide of 1381±72 μA ? mM^?1 ? cm^?2, and a detection limit of 0.86±0.19 μM (S/N=3). This simple and rapid metallization method converts carbon fiber microelectrodes, which are readily accessible, to microscale Pt electrodes in 2 min, providing a platform for oxidase‐based amperometric biosensors with improved spatial resolution over more commonly used platinum electrode array microprobes.     

Photoassisted Catalytic Oxidation of Carbon Monoxide at Room Temperature

Summary. The thermal and photoassisted catalytic oxidation of CO at metal oxide supported RuO₂·xH₂O was studied at room temperature. Contrary to neat RuO₂·xH₂O the supported catalysts suffer from fast deactivation attributed to strong adsorption of the reaction product carbon dioxide. The latter can be efficiently removed from the catalyst surface at elevated temperatures. In some cases, i.e. for catalysts supported with selected n-type semiconductors (TiO₂, SnO₂, WO₃), efficient CO₂ desorption and good, constant catalytic activity was observed upon visible light irradiation. Under such conditions the CO to CO₂ conversion observed for RuO₂·xH₂O/TiO₂ was nearly as good and stable as for the unsupported catalyst. It is suggested that light absorption promotes carbon dioxide desorption through positive charging of the catalyst surface.     

Hydrothermal synthesis,crystal structure and third-order nonlinear optical properties of a 3D coordination polymer containing 3,3′,4,4′-benzophenone-tetracarboxylate (BPTC) and pyrazine ligands

A mixed-ligand compound, [Ni₂(BPTC)(pyz)?·?2H₂O] _n (0.5H₂O) _n (BPTC?=?3,3′,4, 4′-benzophenone-tetracarboxylate, pyz?=?pyrazine), has been prepared hydrothermally by assembly of BPTC, NiCl₂·6H₂O and pyz. X-ray diffraction analysis of a single crystal reveals the three-dimensional framework assembled from pyz-pillared two-dimensional sheets. Three types of channels in one direction are established inside the structure. The third-order nonlinear optical (NLO) properties in DMF have been studied by Z-scan technique using an 8?ns laser at 532?nm. The results reveal that the new compound exhibits strong NLO absorption and self-focusing refractive performance (n ₂?=?2.7?×?10^?17?m²?W^?1).     

Prediction of 195Pt NMR chemical shifts of dissolution products of H2[Pt(OH)6] in nitric acid solutions by DFT methods: how important are the counter‐ion effects?

¹⁹⁵Pt NMR chemical shifts of octahedral Pt(IV) complexes with general formula [Pt(NO₃)_n(OH)_{6 ? n}]^2?, [Pt(NO₃)_n(OH₂)_{6 ? n}]^{4 ? n} (n = 1–6), and [Pt(NO₃)_{6 ? n ? m}(OH)_m(OH₂)_n]^{?2 + n ? m} formed by dissolution of platinic acid, H₂[Pt(OH)₆], in aqueous nitric acid solutions are calculated employing density functional theory methods. Particularly, the gauge‐including atomic orbitals (GIAO)‐PBE0/segmented all‐electron relativistically contracted–zeroth‐order regular approximation (SARC–ZORA)(Pt) ∪ 6–31G(d,p)(E)/Polarizable Continuum Model computational protocol performs the best. Excellent second‐order polynomial plots of δ_calcd(¹⁹⁵Pt) versus δ_exptl(¹⁹⁵Pt) chemical shifts and δ_calcd(¹⁹⁵Pt) versus the natural atomic charge Q_Pt are obtained. Despite of neglecting relativistic and spin orbit effects the good agreement of the calculated δ ¹⁹⁵Pt chemical shifts with experimental values is probably because of the fact that the contribution of relativistic and spin orbit effects to computed σ^{iso 195}Pt magnetic shielding of Pt(IV) coordination compounds is effectively cancelled in the computed δ ¹⁹⁵Pt chemical shifts, because the relativistic corrections are expected to be similar in the complexes and the proper reference standard used. To probe the counter‐ion effects on the ¹⁹⁵Pt NMR chemical shifts of the anionic [Pt(NO₃)_n(OH)_{6 ? n}]^2? and cationic [Pt(NO₃)_n(OH₂)_{6 ? n}]^{4 ? n} (n = 0–3) complexes we calculated the ¹⁹⁵Pt NMR chemical shifts of the neutral (PyH)₂[Pt(NO₃)_n(OH)_{6 ? n}] (n = 1–6; PyH = pyridinium cation, C₅H₅NH⁺) and [Pt(NO₃)_n(H₂O)_{6 ? n}](NO₃)_{4 ? n} (n = 0–3) complexes. Counter‐anion effects are very important for the accurate prediction of the ¹⁹⁵Pt NMR chemical shifts of the cationic [Pt(NO₃)_n(OH₂)_{6 ? n}]^{4 ? n} complexes, while counter‐cation effects are less important for the anionic [Pt(NO₃)_n(OH)_{6 ? n}]^2? complexes. The simple computational protocol is easily implemented even by synthetic chemists in platinum coordination chemistry that dispose limited software availability, or locally existing routines and knowhow. Copyright © 2016 John Wiley & Sons, Ltd.     

Effect of chlorine on solid solution formation in ruthenium titanium dioxide coatings

Rutile-type dioxides of titanium and ruthenium form partial solid solutions at temperatures above 1000°C, whereas the miscibility is complete in the temperature range of 350–600°C, when the oxides are coated on titanium or alumina substrates. The present work tends to show that the Ru_xTi_t?xO₂ coatings are metastable solutions wherein the chloride ions are likely to replace the oxide ions on the sublattice O^2? sites. The increase of a and c parameters in the overall composition range are compatible with a Cl/Ru ratio of 2.5 at.% in the rutile lattice. This ratio does not depend upon the titanium content and therefore it is thought that the Cl^? ions are compensated by reduced Ru³⁺ (or Ti³⁺) species. The electrical conductivity retains its metal-like characteristics in the composition range of 30–100% RuO₂, this is accounted for by the existence of RuO π1 bands along (110) directions. The reduced ions in equilibrium with Cl^? would provide additional paths for electron transport along the c-axis, explaining the high values of conductivity in the concentration range of 30–50% RuO₂.     

Synthesis,electrochemical and antimicrobial studies of mono and binuclear iron(III) and oxovanadium(IV) complexes of [ONO] donor tridentate Schiff-base ligands

Tridentate Schiff bases (H₂L¹ or H₂L²) were derived from condensation of acetylacetone and 2-aminophenol or 2-aminobenzoic acid. Binuclear square pyramidal complexes of the type [M₂(L¹)₂]?·?nH₂O (M?=?Fe–Cl, n?=?0; M?=?VO, n?=?1) were accessed from interaction of H₂L¹ with anhydrous FeCl₃ and VOSO₄?·?5H₂O, respectively. A similar reaction with H₂L², however, produced mononuclear complexes [ML²(H₂O) _x ]?·?nH₂O (M=Fe–Cl, x?=?0, n?=?0; M=VO, x?=?1, n?=?1). The compounds were characterized using elemental analysis, FT-IR, UV-Vis, and NMR (for ligand only), and mass spectroscopies and solution electrical conductivity studies. Magnetic susceptibility measurements suggest antiferromagnetic exchange in binuclear Fe(III) and VO(IV) complexes. Thermo gravimetric analysis (TGA) provided unambiguous evidence for the presence of coordinated as well as lattice water in [VOL²(H₂O)]?·?H₂O. Cyclic voltammetric studies showed well-defined redox processes corresponding to Fe(III)/Fe(II) and VO(V)/VO(IV). In vitro antimicrobial activities of the compounds were investigated against Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeroginosa, Escherichia coli, Bacillus subtilis, and Proteus vulgaris. H₂L¹ and its binuclear complexes exhibited pronounced activity against all the microorganisms tested.     

High Performance Oxide Functionalized Nitrogen‐Doped Mesocellular Carbon Foam for Biosensor Construction

Nitrogen‐doped mesocellular carbon foam (denoted as MCF? CN_x) with high surface area and large pore volume was prepared and characterized in detail. The MCF? CN_x was further functionalized by oxidation with HNO₃ (denoted as MCF? CN_x‐O) in order to effectively improve its hydrophilicity and biocompatibility. Both MCF? CN_x and MCF? CN_x‐O were used for immobilization of Hb and design of electrochemical biosensors. The activity of Hb immobilized on MCF? CN_x‐O is two times higher than that of Hb immobilized on MCF? CN_x. The Hb‐MCF? CN_x‐O‐Nafion modified electrode displays fast response, high sensitivity and low detection limit to the detection of hydrogen peroxide. The sensitivity of Hb‐MCF? CN_x‐O‐Nafion modified electrode (477 μA mM^?1 cm^?2) is twice that of Hb‐MCF? CN_x‐Nafion modified electrode.     

Synthesis, Spectroscopic and Electrochemical Investigations of Two vic-Dioximes and Their Mononuclear Ni（Ⅱ）, Cu（Ⅱ） and Co（Ⅱ） Metal Complexes Containing Morpholine Group

Two vic-dioxime ligands （LxH2） containing morpholine group have been synthesized from 4-[2-（dimethylaminoethyl）] morpholine with anti-phenylchloroglyoxime or anti-monochloroglyoxime in absolute THF at -15 ℃. Reaction of two vic-dioxime ligands with MCl2·nH2O （M： Ni, Cu or Co and n=2 or 6） salts in 1 ： 2 molar ratio afforded metal complexes of type [M（LxH）2] or [M（LxH）2·2H2O]. All of metal complexes are non-electrolytes as shown by their molar conductivities （Am） in DMF （dimethyl formamide） at 10^-3 mol·L^-1. Structures of the ligands and metal complexes have been solved by elemental analyses, FT-IR, UV-Vis, ^1H NMR and ^13C NMR, magnetic susceptibility measurements, molar conductivity measurements. Furthermore, redox properties of the metal complexes were investigated by cyclic voltammetry.     

Luminescent Amphiphilic 2,6‐Bis(1,2,3‐triazol‐4‐yl)pyridine?Platinum(II) Complexes: Synthesis,Characterization, Electrochemical,Photophysical, and Langmuir–Blodgett Film‐Formation Studies

A new series of platinum(II) complexes with tridentate ligands 2,6‐bis(1‐alkyl‐1,2,3‐triazol‐4‐yl)pyridine and 2,6‐bis(1‐aryl‐1,2,3‐triazol‐4‐yl)pyridine (N7R), [Pt(N7R)Cl]X ( 1 – 7 ) and [Pt(N7R)(C?CR′)]X ( 8 – 17 ; R=n‐C₄H₉, n‐C₈H₁₇, n‐C₁₂H₂₅, n‐C₁₄H₂₉, n‐C₁₈H₃₇, C₆H₅, and CH₂‐C₆H₅; R′=C₆H₅, C₆H₄‐CH₃‐p_, C₆H₄‐CF₃‐p, C₆H₄‐N(CH₃)₂‐p, and cholesteryl 2‐propyn‐1‐yl carbonate; X=OTf^?, PF₆^?, and Cl^?), has been synthesized and characterized. Their electrochemical and photophysical properties have also been studied. Two amphiphilic platinum(II)? 2,6‐bis(1‐dodecyl‐1,2,3‐triazol‐4‐yl)pyridine complexes ( 3‐Cl and 8 ) were found to form stable and reproducible Langmuir–Blodgett (LB) films at the air/water interface. These LB films were characterized by the study of their surface‐pressure–molecular‐area (π–A) isotherms, XRD, and IR and polarized‐IR spectroscopy.     

Microwave-assisted synthesis of organic–inorganic poly(3,4-ethylenedioxythiophene)/RuO2·xH2O nanocomposite for supercapacitor

An organic–inorganic poly(3,4-ethylenedioxythiophene) (PEDOT)/RuO₂·xH₂O nanocomposite (approximately 1 wt.% RuO₂) has been successfully prepared for the first time under microwave irradiation within 5 min with power 900 W via in situ chemical polymerization. The morphology and structure of the resultant material is characterized by transmission electron microscope and Fourier transform infrared. Moreover, the electrochemical properties of the synthesized nanocomposite can be controlled by adjusting the annealing temperature, which is definitely illustrated by cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectra. Electrochemical data have shown that the PEDOT/RuO₂·xH₂O nanocomposite annealed at 150 °C possesses the most favorable charge/discharge ability with a specific capacitance of 153.3 F g⁻¹ at a current density of 150 mA g⁻¹ and the high efficient utilization of PEDOT at various current densities. Furthermore, such composite has a less capacitance degradation of 23.8% after 1,000 continuous cycles. The improved electrochemical performance are mainly attributed to the large electroactive surface of nanocomposite and the existence of amorphous RuO₂·xH₂O particles as well as a synergistic effect of the polymer PEDOT and annealed RuO₂·xH₂O. Thus, the PEDOT/RuO₂·xH₂O nanocomposite annealed at 150 °C can act as a promising electroactive material for supercapacitor application.     

Sol-gel synthesis of hydrous ruthenium oxide nanonetworks from 1,2-epoxides

Hydrous ruthenium oxide (RuO₂·xH₂O) xerogels were synthesized through the addition of a 1,2-epoxide, propylene oxide, to commercial hydrated ruthenium chloride, “RuCl₃·xH₂O,” in ethanol. After a blue-black monolithic gel formed in 4 h, the samples were allowed to age for 24 h and were dried in ambient conditions. The dried samples were then characterized by XPS, XRD, DTA and TGA. XPS showed the Ru(3d_5/2) peak at a binding energy of 281.7 eV, corresponding to that of hydrous ruthenium oxide. XRD data revealed the synthesized material as amorphous. Heating the sample in inert atmospheres caused the complete reduction of the oxide to the zero-valent state, whereas heating the sample in air resulted in both crystalline anhydrous RuO₂ and zero-valent ruthenium, depending on the method of heating. DTA traces showed an endotherm ending at 150 °C, corresponding to the loss of coordinated water, as well as two higher temperature crystallization exotherms when the sample was heated in both inert and oxygen-rich atmospheres. TGA runs also confirmed the complete reduction of the hydrous oxide when heated in nitrogen below 270 °C and the formation of anhydrous ruthenium oxide when heated in air, confirming the XRD results.