Crystal structure of bis-[4-(1H-pyrrol-1-yl)phen-yl] ferrocene-1,1'-di-carboxyl-ate: a potential chemotherapeutic drug.

The title iron(II) complex, [Fe(C16H12NO2)2], crystallizes in the ortho-rhom-bic space group Pbca with the Fe(2+) cation positioned on an inversion center. The cyclo-penta-dienyl (Cp) rings adopt an anti conformation in contrast with other substituted ferrocenes in which the Cp rings appear in a nearly eclipsed conformation. The Cp and the aromatic rings are positioned out of the plane, with a twist angle of 70.20 (12)°, and the C(Cp)-C(CO) bond length is shorter than a typical C-C single bond, which suggests a partial double-bond character and delocalization with the Cp π system. The structure of the complex is compared to other functionalized ferrocenes synthesized in our laboratory

New records of suctorians (Ciliophora: Suctoria) as epibionts of aquatic true bugs (Hemiptera: Prosorrhyncha: Nepomorpha) from two regions: Mexico and Eastern Europe

Here, we provide new records of suctorians (Ciliophora: Suctoria), epibionts of aquatic true bugs (Hemiptera: Prosorrhyncha: Nepomorpha) collected in Ukraine, Belarus and Mexico. The worldwide distribution of the 16 species we found is updated, from which, 15 species are new records as epibionts of 15 species of aquatic true bugs. Only for the suctorian Discophrya gessneri Matthes, we confirm the previous record (epibiont of Aphelocheirus aestivalis Fabricius). We conclude that the relationship between the suctorians and aquatic true bugs is poorly studied and some suctorian genera (Discophrya Lachmann and Periacineta Collin) inhabit as nepomorphans as other aquatic insects (Coleoptera). However the high degree of specificity at the species level of these genera is evident, for which we provide some possible explanations according to the group of basibiont

Periacineta mexicana n. sp. (Ciliophora, Suctoria, Discophryida), Epizoic on Mexican Backswimmers of the Genus Buenoa (Insecta, Hemiptera, Notonectidae)

A new species of suctorian in the genus Periacineta, epibiotic on aquatic bugs (Hemiptera, Heteroptera, Nepomorpha), is described on the basis of morphological characteristics of the cell body, lorica, tentacular placement, and stalk, and its 18S rRNA partial sequence gene. Periacineta mexicana n. sp. is a loricate suctorian with elongate body and rounded apical region; tentacles are distributed randomly over apical region and not grouped into fascicles. Macronucleus in adult is elongate and located centrally. The suctorian usually forms closely aggregated pseudocolonies. We provide morphological data based on optical and scanning electron microscopy. A comparison with similar congeners, and emended diagnosis of the genus Periacineta also are provided. The ciliates were found attached to the first two pairs of legs of Mexican notonectids Buenoa pallens and Buenoa spp. (backswimmers)