Synthesis, characterization and molecular modeling of new ruthenium(II) complexes with nitrogen and nitrogen/oxygen donor ligands

Ru(II) complexes with some dinitrogen ligands; 3,4-diamino benzoic acid (DABA), 2-hydazinopyridine (hzpy), 2,2′-bipyridyl (bipy) and anthranilic acid (anth) have been synthesized and characterized by using IR, mass, and UV–Vis spectrometry and thermal analysis. The thermodynamic parameters (ΔE, ΔH, ΔS and ΔG) have been calculated by using Coats–Redfern and Horowitz–Metzger methods. The electrochemical properties of these complexes have been studied by using cyclic voltammetry. The evaluated energies of the HOMO and LUMO are in the range of −4.94 to −4.85 eV and −2.86 to −2.68 eV, respectively. The complexes have been proven to have an octahedral geometry with DABA, hzpy and bipy as N2 donor ligands and NSC as monodentate ligand. The structure of the Ru(II) complexes has been geometrically optimized by using parameterized PM3 semiempirical method. © 2015 The Author

Physico-chemical properties of some polymer blended task specific novel S-(+)-2-3-dihydroxy-N, N, N-tributyl-propanaminiumtriflate and 1-(2-propoxy)- 3-methylimdazolium-borohydride room temperature ionic liquids

Two novel chiral ionic liquids S-(+)-2-3-dihydroxy-N, N, N-tributyl-propanaminiumtriflate and 1-(2-propoxy)-3-methylimdazolium-borohydride have been prepared using conventional metathesis reaction. These ionic liquids have been subjected to solution cast method followed by ultrasonication to obtain the corresponding ionic liquid gel polymer electrolytes with poly (vinylidene fluoride-co-hexafluoropropene) (PVDF-HFP), free-standing, rubbery, dimensionally stable films with a high degree of transparency have been obtained. Thermo-gravimetric analysis confirms that the intermediate solvent, acetone used for mixing PVDF-HFP polymer with ionic liquid is completely evaporated after gelation and drying process. Further thermal properties have been analyzed by differential scanning calorimetry. Scanning electron microscopy micrographs show the different surface morphology of the gel electrolytes according to nature of the ionic liquid. The structural information has been extracted by X-ray diffraction. The ionic conductivities of both polymer-ionic liquid blends are in the order of 10-3 to 10-5 S cm-1. Electrochemical stability window of these polymer electrolytes ranges from 4.0 to 5.0 V. Various physicochemical properties and fast ion conduction in the gel polymer membranes show their promising characteristics as electrolytes in different ionic devices

Titanium dioxide nanostructures in new and emerging energy technologies

Titanium dioxide has been used as the white pigment since the ancient times.95% of its current usage in industry involves paints, cosmetics, plastics, paper, and food. However, in near future the economic impact of titanium dioxide seems to be controlled by energy related applications mostly. Therefore, this chapter projects a brief outlook on the added value provided by the titanium dioxide structures in new and emerging technologies of the energy sector. The applications focused are: solar fuels, solar cells, fuel cells, Li ion batteries and solid state lighting. In those applications, TiO2 standouts with its chemical and thermal stability, morphology variety, position of conduction and valance band energy levels, optical properties and cost. © 2014 by Nova Science Publishers, Inc. All rights reserved

organic light-emitting diodes

Iridium(III) complexes containing two 2-(3-fluorophenyl)-4-methylpyridine and one branched alkyl side group on the 2,2'-bipyridine ligand were synthesized and characterized by UV-Visible, fluorescence, FTIR, NMR spectroscopies, thermal gravimetric analysis (TGA) and cyclic voltammetry. The complexes containing 4-dihexylmetyl-4'-heptyl-2,2'-bipyridine, 4,4'-bis(3-ethylheptyl)-2,2'-bipyridine and 4-(3-ethylheptyl)-4'-methyl-2,2'-bipyridine are named as CS137, CS138 and CS139, respectively, and exhibit a yellow emission band at around 590 nm. The photoluminescence quantum yields are in the range of 0.63-0.72 in chlorobenzene. The TGA curves of the complexes present high decomposition temperatures above 280 degrees C. The HOMO and LUMO energy levels are in the range of -5.36-(-5.43) eV and -3.21-(-3.27) eV, respectively. Solution processed organic light-emitting diodes are fabricated by the use of these complexes as dopants at various concentrations in the poly(N-vinyl carbazole: 1,3-bis [(4-tert-butylphenyl)-1,3,4-oxadiazolyl] phenylene host. Almost no electroluminescence could be obtained from the blend containing CS139 whereas those of CS137 and CS138 resulted in white light. Commission Internationale de L'Eclairage (CIE) chromaticity coordinates shifted to the yellow region with the increase in complex ratio in the blend. The obtained device characteristics are attributed to the positive effects of higher steric hindrance in CS137 and CS138

A Study about Connection and Development from Living Environment Studies to Social Studies

Iridium(III) complexes containing 2-(3-fluorophenyl)-4-methylpyridine and amidinate ligands with alkyl chains were synthesized and characterized by UV/Visible, fluorescence, FTIR, NMR spectroscopies and cyclic voltammetry. Thermal properties of the iridium complexes have been investigated using thermogravimetric analysis (TGA). The influence of alkyl side groups on the photoluminescence spectra of iridium complexes has been investigated. The spectra of all complexes show similar emission which results in the blue region. However, the increase in the solution concentrations of the complexes leads to excimer emission in the amidinate complexes. The effects of different polarities of solvents on photophysical properties have been investigated. The HOMO and LUMO energy levels of the complexes are in the range of 5.32-5.35 eV and 2.48-2.51 eV, respectively. The energy states, thermal and electrochemical stability of the complexes are appropriate for their utilization in OLED applications. (c) 2014 Elsevier BY. All rights reserved

Conventional and inverted UV-PDs based on solution processed PFE:ZnO active layer

Solution processed ultraviolet photodetectors with conventional and inverted architectures with active layers composed of poly(9,9-dioctylfluorenyl-2,7-yleneethynylene) (PFE) and zincoxide (ZnO) nanoparticle hybrid are introduced. Under 1 mW/cm2 illumination intensity at 365 nm wavelength and for-4 V bias and room temperature, the conventional device structure of ITO/PEDOT:PSS/PFE:ZnO/Al and the inverted device structure of ITO/PFE:ZnO/Au are yielded photoresponsivity values of 311 and 244 mA/W, detectivity values of 1.4 × 1014 and 5.1× 1013 cmHz1/2 W-1, and external quantum efficiency values of 105.6% and 82.7%, respectively. By annealing the active layer at polymer's glass transition temperature (Tg; 60 °C) for 15 min, these values are increased to 375 and 280 mA/W, 1.6 × 1014 and 5.3 × 1013 cmHz1/2W-1, 127% and 95%, as in the above order. Performance, stability, and detectivity value differences between conventional and inverted architectures are explained electrically by impedance spectroscopy. © 2014 IEEE