Raman spectroscopic identification of fullerene inclusions in polymer/fullerene blends

Thin films of the conjugated polymer poly(3‐hexylthiophene) (P3HT) and blends of the soluble fullerene derivative[6,6]‐phenyl C₆₁‐butyric acid methyl ester (PCBM) with P3HT—a well studied but not completely understood donor–acceptor system for organic solar cells—have been studied by means of UV–visible absorption and resonant Raman spectroscopy. Additionally, we have employed atomic force microscopy phase imaging to characterize the nanomorphology of the P3HT : PCBM thin film, revealing a close intermixing of two phases with domain sizes ranging from a few to several tens of nanometers. A systematic analysis of pristine polymer and blend Raman spectra provides evidence that features attributable to PCBM, possibly even depending on the charge state of the fullerene molecule, can be observed. Hence our results suggest that fullerene inclusions in polymer/fullerene blends can be identified via Raman spectroscopy. Copyright © 2011 John Wiley & Sons, Ltd.     

Spectroscopic infrared ellipsometry by means of FTS

The use of visible and UV Fourier transform spectrometers for intensity measurement in emission spectra is described. The intensity ratio between different methods of excitation is a useful aid to term analysis: It can be used to confirm an assignment or to indicate an upper state excitation energy. The ratio may be used as a substitute for other confirming data such as the Zeeman effect or hfs. Examples are given from the analysis of Fe I. Illustrative results on line profiles and on continuum observations in the far UV are also presented.     

Synthese und dynamisches verhalten des 1-pentamethylcyclopentadienyl-2,3,4,5,6-pentamethyl-2,3,4,5,6-pentacarba-nido-hexaboran-kations

In the reaction of pentamethylcyclopentadienyldichloroborane with pentamethylcyclopentadienyllithium bis(pentamethylcyclopentadienyl)chloroborane is formed, from which the 1-pentamethylcyclopentadienyl-2,3,4,5,6-pentamethyl-2,3,4,5,6-pentacarba-nido-hexaborane cation can be synthesized by halogen abstraction. Investigations concerning the dynamic behaviour of the cluster are described.     

Infrared reststrahlen revisited: commonly disregarded optical details related to <Emphasis Type="Italic">n</Emphasis><1

Spectral ellipsometry has developed into a routine method applicable to the infrared spectral range. It can give both the refractive index (n) and the absorption index (k), which has so far only been determined for a limited number of compounds. It turns out that vibrations that have a dispersion with an interval of n<1 are by no means restricted to crystals, but occur with numerous compounds including polymers and liquids. In conventional infrared spectroscopy, one usually is not aware of such a situation and so the consequences are disregarded. These include the so-called reststrahlen (residual rays) bands and specific phenomena that occur when n matches the absorption index (the Berreman effect) or the refractive index of ambient air (vanishing reflection, the Christiansen effect). These and some typical applications are discussed, including model calculations and experimental data.Dedicated to the memory of Wilhelm Fresenius     

An efficient implementation of a drug candidate database

The recent advances in laboratory technologies have resulted in a wealth of chemical and biological data. The rapid proliferation of a vast amount of data has led to a set of cheminformatics and bioinformatics applications that manipulate dynamic, heterogeneous, and massive data. An example of such application in the pharmaceutical industry is the computational process involved in the early discovery of lead drug candidates for a given target disease. In this paper, an efficient implementation of a drug candidate database is presented and evaluated. This study shows that high performance data access can be achieved through proper choices of data representation, database schema design, and parallel processing techniques.