Nanocomposite of polyaniline formed within ionic liquid derived ordered mesoporous carbon (PANi@IOMC) was prepared by polymerization of aniline in the presence of IOMC for electrochemical capacitors. The morphology and structure of the nanocomposite were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and porosimetry. To fabricate the supercapacitor electrode, an appropriate mixture of PANi@IOMC nanocomposite and activated carbon was sonicated in acetone, and then the resulting dispersion was coated on the carbon fiber paper using a spray-coating technique. Because of relatively high surface area of nanocomposite for Faradic redox reactions, a maximum specific capacitance of 542 F g -1 in addition to 85% specific capacitance retention after 1000 successive charge-discharge cycles were obtained. The excellent electrochemical performance of the nanocomposite compared to the pure PANi or IOMC, was attributed to the covalent bonding between PANi and carbon structure in the presence of N-phenyl-p-phenylenediamine (NPP) as an initiator for linking the polymer chains to the surface. The results of the present work highlight the efficiency of the interfacial chemistry of NPP in generating the nanocomposite with enhanced conductivity and high surface area. IntroductionSupercapacitors, also known as electrochemical capacitors, represent an important class of energy storage systems because of their desirable properties such as long cycle lifetime, high power density, fast charge and discharge rates and excellent operational stability. Depending on the electrode material and the energy storage mechanism, there are two major categories of supercapacitors 1-8 . The first type is electrical double layer capacitors (EDLCs) that employ carbon based materials and their charge storage ability originates from Non-Faradaic processes.It should be noted that EDLCs store the electric charges by reversible electrostatic adsorption of electrolyte ions at the surface of the electrode. Thus, the properties of the employed electrode materials and the electrolyte in the supercapacitor structure play the most important role in the supercapacitive performance of EDLCs. The second type is pseudocapacitors in which the charge storage mechanism strongly depends on the Faradaic reactions occur at the exterior or interior surfaces of the electrode materials 1, 9, 10 . Pseudocapacitors can be divided into two groups; pseudocapacitors based on transition metal oxides/hydroxides and pseudocapacitors based on conducting polymers. Transition metal oxides/hydroxides can be utilized for relatively fast and reversible redox reactions to take place at the surface of electrode materials. However, most of the metal oxides suffer from poor electrical conductivity, although they have high specific capacitances. In contrast with the first group, the second group of pseudocapacitors based on conducting polymers offer remarkable electrical conductivity in addition to high ...

The preparation and characterization of new heteronuclear-platinum(ii) complexes containing a 1,1'-bis(diphenylphosphino)ferrocene (dppf) ligand are described. The reaction of the known starting complex [PtMe(κN,C-bipyO-H)(SMe)], A, in which bipyO-H is a cyclometalated rollover 2,2'-bipyridine N-oxide, with the dppf ligand in a 2 : 1 ratio or an equimolar ratio led to the formation of the corresponding binuclear complex [PtMe(κN,C-bipyO-H)(μ-dppf)], 1, or the mononuclear complex [PtMe(κC-bipyO-H)(dppf)], 2, respectively. According to the reaction conditions, the dppf ligand in 1 and 2 behaves as either a bridging or chelating ligand. All complexes were characterized by NMR spectroscopy. The solid-state structure of 2 was determined by the single-crystal X-ray diffraction method and it was shown that the chelating dppf ligand in this complex was arranged in a "synclinal-staggered" conformation. Also, the occurrence of intermolecular C-HO interactions in the solid-state gave rise to an extended 1-D network. The electronic absorption spectra and the electrochemical behavior of these complexes are discussed. Density functional theory (DFT) was used for geometry optimization of the singlet states in solution and for electronic structure calculations. The analysis of the molecular orbital (MO) compositions in terms of occupied and unoccupied fragment orbitals in 2 was performed.

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