[Ag(tht)(OTf)]-assisted reaction produces [Au III (dppm)(tht) 2 ] , reacts with RaaiR ′ in dichloromethane medium followed by ligand addition, and leads to [Au III (dppm)(RaaiR ′ )](OTf) 2 (RaaiR ′ = p –R–C 6 H 4 –N = N–C 3 H 2 –NN–1–R ′ , ( 1–3 ), abbreviated as N,N ′ -chelator, where N(imidazole) and N(azo) represent N and N ′ , resp.; R = H ( a ), Me ( b ), Cl ( c ) and R ′ = Me ( 1 ), CH 2 CH 3 ( 2 ), CH 2 Ph ( 3 ), dppm is diphenylphosphinomethane, OSO 2 CF 3 is the triflate anion, and tht is tetrahydrothiophen). Ir spectra of the complexes show –C=N– and –N=N– stretching near at 1590 and 1370 cm −1 and near at 1100, 755, 695, 545, and 505 cm −1 due to the presence of dppm. The 1 H NMR spectral measurements suggest that methylene, –CH 2 –, in RaaiEt gives a complex AB type multiplet while in RaaiCH 2 Ph it shows AB type quartets. Electrochemistry assigns ligand reduction.
Conjugated polymers containing carbazole moieties either in the main or in the side chains have attracted much attention because of their unique electronic properties, to their high photoluminescence quantum efficiency, and thermal stability. The aim of this work is to study a new organic copolymer which combines the PVK properties and those of PHT. We will describe in this study the protocol synthesis, the chemical structure, and the electronic and vibrational properties of the resulting copolymer. The experimental and theoretical studies are combined in order to describe the properties of this material. These properties suggest this compound (PVK-PHT) to be a good candidate for optoelectronic application.
Ternary mixtures formed from components of the five series of unsymmetrical 1,4-phenylene bis-4-substituted benzoates (Ina--e), in which the substituent (X) alternatively changed from CH3O,CH3, Cl, NO2, and CN, respectively, while, within each homologous series, the length of the terminal alkoxy group varies between n=6, 8, or 14 carbons, were prepared and characterized for their mesophase behaviour. Transition temperatures of the mixtures prepared were measured by differential scanning calorimetry and the phases identified by polarized-light microscopy.
The migration of nickel was studied for a set of twelve new units of piercing jewellery and eleven ones used for longer than one year. First, the surface of the samples was analysed using ED XRF and then samples were submerged into the artificial sweat solution for 168 hours at 30∘C. The resulting solutions were then analysed using ICP OES. A significant migration of nickel was found for four samples used, whereas only one of them was considered to exceed the migration limit given by ČSN EN 1811 +A1. Regrettably, no connection between elemental composition of particular jewellery sample measured by ED XRF and corresponding Ni release to the artificial sweat was observed.
