2,3,6,7-Tetra­kis(bromo­meth­yl)naphthalene

The title compound, C14H12Br4, crystallizes with imposed inversion symmetry. In the crystal, the mol­ecules pack in layers parallel to (10). The layers involve two Br⋯Br and one H⋯Br contact. Between the layers, one contact each of types Br⋯Br, H⋯Br and Br⋯π is observed

Ensembl Genomes 2022: an expanding genome resource for non-vertebrates

Ensembl Genomes (https://www.ensemblgenomes.org) provides access to non-vertebrate genomes and analysis complementing vertebrate resources developed by the Ensembl project (https://www.ensembl.org). The two resources collectively present genome annotation through a consistent set of interfaces spanning the tree of life presenting genome sequence, annotation, variation, transcriptomic data and comparative analysis. Here we present our largest increase in plant, metazoan and fungal genomes since the project’s inception creating one of the world’s most comprehensive genomic resources and describe our efforts to reduce genome redundancy in our Bacteria portal. We also detail our new efforts in gene annotation, our emerging support for pangenome analysis and efforts to accelerate data dissemination through the Ensembl Rapid Release resource. We also present our new AlphaFold visualisation. Finally, we present details of our future plans including updates on our integration with Ensembl, and how we plan to improve our support for the microbial research community. Software and data are made available without restriction via our website, online tools platform and programmatic interfaces (available under an Apache 2.0 license). Data updates are synchronised with Ensembl’s release cycle

a new tsunami catalogue

Abstract. Data on tsunamis occurring in the Black Sea and the Azov Sea from antiquity up to the present were updated, critically evaluated and compiled in the standard format developed since the 90’s for the New European Tsunami Catalogue. Twenty nine events were examined but three of them, supposedly occurring in 557 AD, 815 AD and 1341 or 1343, were very likely falsely reported. Most of the remaining 26 events were generated in Crimea, offshore Bulgaria as well as offshore North Anatolia. For each of the 26 events examined, 22 events were classified as reliable ones receiving a score of 3 or 4 on a 4-grade reliability scale. Most of them were caused by earthquakes, such as the key event 544/545 of offshore Varna, but a few others were attributed either to aseismic earth slumps or to unknown causes. The tsunami intensity was estimate

Conformational Behavior of Pyrazine-Bridged and Mixed-Bridged Cavitands: A General Model for Solvent Effects on Thermal Vase-Kite Switching

The controllable switching of suitably bridged resorcin[4]arene cavitands between a "vase" conformation, with a cavity capable of guest inclusion, and a "kite" conformation, featuring an extended flattened surface, provides the basis for ongoing developments of dynamic molecular receptors, sensors, and molecular machines. This paper describes the synthesis, X-ray crystallographic characterization, and NMR analysis of the "vase-kite" switching behavior of a fully pyrazine-bridged cavitand and five other mixed-bridged quinoxaline-bridged cavitands with one methylene, phosphonate, or phosphate bridge. The pyrazine-bridged resorcin[4]arene cavitand displayed an unexpectedly high preference for the kite conformation in nonpolar solvents, relative to the quinoxaline-bridged analogue. Ibis observation led to extensive solvent-dependent switching studies that provide a detailed picture of how solvent affects the thermal vase-kite equilibration. As for any thermodynamic process in the liquid phase, the conformational equilibrium is affected by how the solvent stabilizes the two individual states. Suitably sized solvents (benzene and derivatives) solvate the cavity of the vase form and reduce the propensity for the vase-to-kite transition. Correspondingly, the kite geometry becomes preferred in bulky solvents such as mesitylene, incapable of penetrating the vase cavity. As proposed earlier by Cram, the kite form is preferred at low temperatures due to the more favorable enthalpy of solvation of the enlarged surface. Furthermore, the kite conformation is more preferred in solvents with substantial hydrogen-bonding acidity: weak hydrogen-bonding interactions between the mildly basic quinoxaline and pyrazine nitrogen atoms and solvent molecules are more efficient in the open kite than in the closed vase form. Vase-to-kite conversion is entirely absent in dipolar aprotic solvents lacking any H-bonding acidity. Thermal vase-kite switching requires fully quinoxaline- or pyrazine-bridged cavitands, whereas pH-controlled switching is also applicable to systems incorporating only two or three such bridges