Persistent Room Temperature Phosphorescence from Triarylboranes: A Combined Experimental and Theoretical Study.

Achieving highly efficient phosphorescence in purely organic luminophors at room temperature remains a major challenge due to slow intersystem crossing (ISC) rates in combination with effective non-radiative processes in those systems. Most room temperature phosphorescent (RTP) organic materials have O- or N-lone pairs leading to low lying (n, π*) and (π, π*) excited states which accelerate k through El-Sayed's rule. Herein, we report the first persistent RTP with lifetimes up to 0.

New Outcomes of Beryllium Chemistry: Lewis Base Adducts for Salt Elimination Reactions.

A range of mono- and bis-adducts of beryllium dichloride with cyclic (alkyl)(amino)carbenes (CAAC), cyclic diamidocarbene (DAC), and carbodiphosphorane (CDP) are prepared, and their reactions with nucleophiles are studied. Salt elimination with Yamashita and Nozaki's lithium diazaborolide reagent led to the isolation of an unsymmetrical beryllium diazaborolyl complex and a base-stabilized diazaborolyl beryllium chloride. From structural and spectroscopic analyses, the Be-B bonding in these compounds was determined to be polar covalent in character.

Reactions of Digallanes with p- and d-Block Lewis Bases: Adducts, Bis(gallyl) Complexes, and Naked Ga as Ligand.

A range of double carbene adducts of digallanes(4) are prepared from an existing double digallane adduct, and their halides are subsequently exchanged, establishing the feasibility of both base and halide-exchange reactions from digallane adducts. Furthermore, a range of digallium species are treated with transition-metal Lewis bases, leading alternatively to oxidative addition products, species with monocoordinate Ga ligands, and an unusual ditopic metal-only Lewis pair (MOLP). These results underline the manifold and unpredictable chemistry of halogallane species with Lewis bases.

Neutral zero-valent s-block complexes with strong multiple bonding.

The metals of the s block of the periodic table are well known to be exceptional electron donors, and the vast majority of their molecular complexes therefore contain these metals in their fully oxidized form. Low-valent main-group compounds have recently become desirable synthetic targets owing to their interesting reactivities, sometimes on a par with those of transition-metal complexes. In this work, we used stabilizing cyclic (alkyl)(amino)carbene ligands to isolate and characterize the first neutral compounds that contain a zero-valent s-block metal, beryllium.

A Novel Lineage of 'Naked Filose Amoebae'; Kraken carinae gen. nov. sp. nov. (Cercozoa) with a Remarkable Locomotion by Disassembly of its Cell Body.

The term 'filose amoebae' describes a highly polyphyletic assemblage of protists whose phylogenetic placement can be unpredictable based on gross morphology alone. We isolated six filose amoebae from soils of two European countries and describe a new genus and species of naked filose amoebae, Kraken carinae gen. nov.

Regulation of cell wall-bound invertase in pepper leaves by Xanthomonas campestris pv. vesicatoria type three effectors.

Xanthomonas campestris pv. vesicatoria (Xcv) possess a type 3 secretion system (T3SS) to deliver effector proteins into its Solanaceous host plants. These proteins are involved in suppression of plant defense and in reprogramming of plant metabolism to favour bacterial propagation.

Total synthesis of (-)-zampanolide and structure-activity relationship studies on (-)-dactylolide derivatives.

A new total synthesis of the marine macrolide (-)-zampanolide (1) and the structurally and stereochemically related non-natural levorotatory enantiomer of (+)-dactylolide (2), that is, ent-2, has been developed. The synthesis features a high-yielding, selective intramolecular Horner-Wadsworth-Emmons (HWE) reaction to close the 20-membered macrolactone ring of 1 and ent-2. The β-keto phosphonate/aldehyde precursor for the ring-closure reaction was obtained by esterification of a ω-diethylphosphono carboxylic acid fragment and a secondary alcohol fragment incorporating the THP ring that is embedded in the macrocyclic core structure of 1 and ent-2.