Electrochemistry and Ion Sensing Properties of Conducting Hydrogel Layers Based on Polypyrrole and Alkoxysulfonated Poly(3,4‐ethylenedioxythiophene) (PEDOT‐S)

Acidic aqueous solutions containing pyrrole and alkoxysulfonated PEDOT derivative (PEDOT‐S) were found to undergo polymerization in the absence of an external oxidizing agent. The product was a nearly black‐colored conducting hydrogel that after separation could be dispersed in water or acetone. The suspensions could be used to deposit cast films on a polycrystalline gold electrode. The polymer modified electrode showed a nearly Nernstian potentiometric response to Ag⁺ cations in the concentration range of 10^?5–10^?1 M with the slope of 54 mV/decade. The response was specific to Ag⁺ compared to a series of alkali and transition‐metal cations (pK_Ag/M>3.7).     

Enthalpy of fusion of poly(3‐hexylthiophene) by differential scanning calorimetry

The enthalpy of fusion for a perfect, infinite poly(3‐hexylthiophene) (P3HT) crystal () must be known to evaluate the absolute crystallinity of P3HT. This value, however, is still ambiguous as different values have been reported using various experimental techniques. Here, we extrapolate the enthalpy of fusion for extended chain crystals of oligomeric P3HT to infinite molecular weight and obtain a value of 42.9 ± 2 J/g employing differential scanning calorimetry with a correction based on grazing incidence small angle X‐ray scattering data. Also, we define the onset of chain folding within P3HT crystallites at a chain length of 5 Kuhn segments. Knowledge of allows calculation of P3HT percent crystallinity in thin films for applications such as organic field effect transistors and solar cells. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 1469–1475     

Control design of the vibration reduction systems

The paper deals with an original control algorithm for semi-active and active suspension that are often used in automotive systems. The developed procedure assists in finding the structure of control system, which consists of the primary controller and calculates the desired active force. Then the desired force has to be approximately achieved by the semi-active or active element with calculated input signal using the inverse model. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Molecular level structure of novel synthetic analogues of aliphatic biopolyesters as revealed by multistage mass spectrometry

The present study focuses on electrospray ionisation (ESI) tandem mass spectrometry of novel copolyesters obtained by anionic ring-opening copolymerisation of β-substituted β-lactones. Detailed analysis of these copolyesters, including molecular chain architecture as well as the structures of the end groups, was performed using ESI-MS/MS collision-induced dissociation spectra. The random arrangement of comonomeric units along the copolyester chains was demonstrated by comparison of ESI-MSⁿ fragmentation spectra and fragmentation pathways. Sequence distribution analysis of comonomeric units confirmed the copolymer's random structure. ESI-MSⁿ proved to be a promising technique for structural analysis of copolyesters obtained via anionic ROP.     

Time-effective and reliable solid-state structure evaluation of selected peracetylated β-maltose derivatives by means of grid search,genetic algorithm and DFT calculations

Efficient solid-state structure evaluation of β-maltose octaacetate (1), methyl β-maltoside heptaacetate (2), and ethyl 1-thio-β-maltoside heptaacetate (3) was performed. The search for the best conformers for 1–3 was conducted in three consecutive steps: grid search, genetic algorithm refinement and DFT study. The use of a genetic algorithm caused a spectacular time shortening of the calculations. The obtained theoretical conformation for 1 resembled its XRD refinement almost perfectly. Although XRD analysis was impossible to perform for 2 and 3 (they form improper crystals), their reliable conformations were obtained. It was proved by the use of ¹³C CP/MAS NMR spectroscopy.     

Reliable evaluation of molecular structure of methyl 3-O-nitro-α-d-glucopyranoside and its intermediates by means of solid-state NMR spectroscopy and DFT optimization in the absence of appropriate crystallographic data

In this paper the comparative structural analysis of a series of compounds (methyl α-d-glucopyranoside, methyl 4,6-O-ethylidene-α-d-glucopyranoside (2), methyl 2,3-di-O-nitro-4,6-O-ethylidene-α-d-glucopyranoside and methyl 3-O-nitro-4,6-O-ethylidene-α-d-glucopyranoside) by way of synthesis leading to methyl 3-O-nitro-α-d-glucopyranoside (5) is reported. The title compound (5) is a novel d-glucosidic mononitrate having potential biological activity against cardiovascular diseases. The structural analysis was supported by single-crystal X-ray diffraction (XRD), ¹³C CP/MAS NMR spectroscopy and DFT calculations. In the case of 2 and 5, XRD analysis could not be performed due to the fact that 2 is highly hygroscopic and 5 forms improper crystals. However, the molecular structures of 2 and 5 were obtained on the basis of experimental (existing XRD data for similar compounds) and theoretical (DFT optimization) approaches. This showed of very good agreement with the ¹³C CP/MAS NMR spectral data.     

Synthesis,Solid‐State NMR Characterization,and Application for Hydrogenation Reactions of a Novel Wilkinson’s‐Type Immobilized Catalyst

Silica nanoparticles (SiNPs) were chosen as a solid support material for the immobilization of a new Wilkinson’s‐type catalyst. In a first step, polymer molecules (poly(triphenylphosphine)ethylene (PTPPE); 4‐diphenylphosphine styrene as monomer) were grafted onto the silica nanoparticles by surface‐initiated photoinferter‐mediated polymerization (SI‐PIMP). The catalyst was then created by binding rhodium (Rh) to the polymer side chains, with RhCl₃ ? x H₂O as a precursor. The triphenylphosphine units and rhodium as Rh^I provide an environment to form Wilkinson’s catalyst‐like structures. Employing multinuclear (³¹P, ²⁹Si, and ¹³C) solid‐state NMR spectroscopy (SSNMR), the structure of the catalyst bound to the polymer and the intermediates of the grafting reaction have been characterized. Finally, first applications of this catalyst in hydrogenation reactions employing para‐enriched hydrogen gas (PHIP experiments) and an assessment of its leaching properties are presented.     

Thermotropic Properties and Molecular Packing of Discotic Tristriazolotriazines with Rigid Substituents

Tristriazolotriazines with a threefold dialkoxyaryl substitution have been prepared by Huisgen reaction of cyanuric chloride and the corresponding tetrazoles. Although these dyes show a negative or inverted solvatochromism of the UV/Vis absorption, their fluorescence is strongly positive solvatochromic. These discotic fluorophores are also emissive in their solid state and in their broad liquid‐crystalline mesophase. The structural study indicates that the thermotropic properties and organization of these systems can be well tuned by the steric demand of the aryl groups. Depending on the substituents, the compounds showed either a pure crystalline phase or a highly complex helical superstructure with a characteristic liquid‐crystalline phase at elevated temperatures. Changing the steric demand of the attached aryls allowed controlling the discs arrangement within the columnar helix, which is of great importance for the molecular orbital overlap.