Novel monomeric, oligomeric, and polymeric charge‐transfer complexes with interesting electrical conductivity properties and even exhibiting superconductivity are expected to be obtainable by the systematic chemical modification of extended tetrathiafulvalenes (see Figure for one example). The synthesis and cyclic voltammetric characterization of such extended donors are reviewed in detail. magnified image

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The Organotin(IV) Coordination Polymer (( ß38 )4 ß(€ )6•2 2 •€4 802)": A Three-Dimensional Host-Guest Network Involving "Cascade-Type" Guests Macroor polycyclic Lewis base receptors1 require an appropriate disposition of Lewis acidic centers over the respective organic rings. Frequently, after the anchoring of at least two metal ions to selected N and/or 0 atoms of the ring as "primary guests",

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A new polymorph of 2,4-dihydroxybenzoic acid is reported. The structure was characterized by multiple-temperature X-ray diffraction and solid-state DFT computations. The material shows a geometric pattern of hydrogen bonding consistent with cooperativity between the intermolecular carboxylic acid dimer and intramolecular hydrogen bonds. The presence of proton disorder within this hydrogen-bond system, which would support such a cooperative model, was not fully ruled out by the initial X-ray studies. However, solid-state calculations on the three possible end-point tautomers indicate that the dominant crystallographically observed configuration is substantially lower in energy than the other tautomers (by at least 9 kJ mol(-1)), indicating that no disorder should be expected. It is therefore concluded that no disorder is observed either in the intra- or intermolecular hydrogen bonds of the title compound and that the cooperativity between the hydrogen bonds is not present within the temperature range studied.

A homologous series of oligo(9,lO-anthry1ene)s up to the heptamer have been synthesized by reductive coupling of quinones with lithioanthrylenes, followed by reductive aromatization of the intermediate hydroxy species. The method used allows the introduction of different alkyl substituents, which ensure sufficient solubility of the newly synthesized anthrylene systems in common organic solvents. The solidstate conformations of trimers 4 and 5 have been established by X-ray structure analysis; UV/Vis-spectroscopic investiga-tions in solution reveal the anthratene moieties in 9,lO-anthrylenes to exist as electronically independent electrophores. The trianthrylenes can b e subjected to electrophilic substitution which regioselectively provides e.g. 10-bromo-and 10,lO"-dibromo derivatives. These bromides can easily b e converted into the corresponding cyano compounds. Under the influence of potassium hydroxide in quinoline the trimer 5 partially cyclizes to helianthrene compounds.

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The analytical method based on the HPLC coupled with UV detection (HPLC-UV) for the determination of selected antioxidants (i.e. esculetin, scopoletin, 7-hydroxycoumarine, rutin, xanthotoxin, 5-methoxypsoralen and quercetin) in plant material was developed. Two ultrasonic extraction methods for the isolation of these compounds from the plants such as Mentha longifolia L., Mentha spicata L., Ruta graveolens L., Achyllea millefolium L., Plantago lanceolata L. and Coriandrum sativum L. were used. Both of these methods, i.e. ultrasonic probe and ultrasonic bath, were optimised and compared to each other. For the proposed HPLC-UV method LOQ values in the range from 22.7 (xanthotoxin) up to 97.2 ng/mL (rutin) were obtained. For all extracts the antioxidant capacity based on the reduction of free 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical was also determined. Obtained results ranged from 10.11 up to 73.50% of DPPH radical inhibition.