Comparison of Antiaromatic Properties in a Series of Structurally Isomeric Naphthothiophene-Fused s-Indacenes.

Fusion of aromatic subunits to stabilize an antiaromatic core allows the isolation and study of otherwise unstable paratropic systems. A complete study of a series of six naphthothiophene-fused s-indacene isomers is herein described. Additionally, the structural modifications resulted in increased π-π overlap in the solid state, which was further explored through changing the sterically blocking mesityl group to (triisopropylsilyl)ethynyl in three derivatives.

Measurement of Interpeptidic Cu Exchange Rate Constants of Cu-Amyloid-β Complexes to Small Peptide Motifs by Tryptophan Fluorescence Quenching.

The interpeptidic Cu exchange rate constants were measured for two Cu amyloid-β complexes, Cu(Aβ) and Cu(Aβ), to fluorescent peptides GHW and DAHW using a quantitative tryptophan fluorescence quenching methodology. The second-order rate constants were determined at three pH values (6.8, 7.