Supramolecular architecture of [AsPh2Br2]2[(Br3)−…(Br2)…(Br3)−] obtained by bromination of (AsPh2)2S

Bromination of (AsPh2)2S leads to cleavage of the sulfide bridge to give AsPh2Br when 1 mol of bromine is used but with 2 mols the product is the polybromide, [AsPh2Br2]2[Br8], containing the previously unknown [AsPh2Br2]+ cation and a rare [(Br3)−…(Br2)…(Br3)−] ensemble whose short (yet not covalent) Br2…Br3 contacts have previously supported tentative description as an octabromide Br82− anion. X-ray crystallography shows that the compound has a three dimensional supramolecular structure based on cooperativity of weak intermolecular Csingle bondH…π, Csingle bondH…Br hydrogen bonds and secondary Br…Br interactions in the solid state. The electronic structure and the stability of the [AsPh2Br2]2[Br8] are rationalized using DFT and HF calculations and molecular orbital considerations

Topics in National Anthems

National anthems are occasionally quoted, mostly based on anecdotal evidence or arguments, to be correlated with societal features. The present study aims to identify the pervasive topics in national anthems, and then to establish whether connections may be established between these topics and some basic societal features. Upon examination of ~200 anthems, such recurring themes were identified: ancestry/past, beauty, build/work, country name, courage, democracy, enemy, ethnicity, family, man, woman, fight, flag/colours, forever/never, future, geographical references, glory, independence/freedom, joy/happiness, home/mother/father-land, law/governance, leader, love, loyalty, peace, poverty/wealth, pride, religion, revolution, sacred, sacrifice, salvation, sorrow, treason, tyrant/chains, unity, win/victory. The number of topics, as well as their bias (e.g., towards identity, or towards fight, or towards general well-being), vary widely between anthems; groups of anthems may be identified based on these tendencies. Moreover, the number of topics, their bias, and/or the date of adoption can be proven to correlate to some extent to more general societal features such as date of adoption, age of country, gross domestic product (GDP) per capita, Gini coefficient, size of armed forces, inequality, inequality-adjusted human development index, and a number of parameters from the World Values Survey (WVS) database (related to religion, gender equality, attitude towards other nationalities/races, attitude towards work, attachment to democratic values etc). This set of data and the herein identified correlations may offer grounds for further, more detailed exploration of a variety of correlations between societal features and official narratives, starting with the national anthems as prime example

Nitrite binding to globins: linkage isomerism, EPR silence and reductive chemistry

The nitrite adducts of globins can potentially bind via O- or N- linkage to the heme iron. We have used EPR (electron paramagnetic resonance) and DFT (density functional theory) to explore these binding modes to myoglobin and hemoglobin. We demonstrate that the nitrite adducts of both globins have detectable EPR signals; we provide an explanation for the difficulty in detecting these EPR features, based on uniaxial state considerations. The EPR and DFT data show that both nitrite linkage isomers can be present at the same time and that the two isomers are readily interconvertible in solution. The millisecond-scale process of nitrite reduction by Hb is investigated in search of the elusive Fe(II)-nitrite adduct

Dioxygen Activation by Copper-Bleomycin: Theoretical Considerations

Density functional theory (DFT) calculations are employed to calculate probable reaction intermediates in dioxygen activation by bleomycin-ligated copper – Cu(I)-dioxygen, Cu(I)-superoxo and Cu(II)-hydroperoxo. The electronic structures of these intermediates are discussed with emphasis on their electromerism. Importantly, unlike in dioxygen activation by iron-bleomycin, formation of these reactive intermediates requires that some of the copper-bleomycin bonds be broken. (doi: 10.5562/cca1793

An inorganic helix in the supramolecular structure of trimethyltin diphenylarsinate, [me3sn(o2asph2)]n: a structural comparison of triorganotin arsinates and phosphinates

The crystallographic structure analysis of [Me3Sn(O2AsPh2)]n reveals supramolecular association owing to symmetric bridges between Me3Sn centres afforded by O2AsPh2 groups. The resulting polymer has a helical topology. A systematic analysis of triorganotin arsinato and phosphinato analogues indicates a role for the remote substituents on aggregations patterns