The first example of a homoleptic Ru^II complex with heteroaryl-imidazoles is reported in the meridional stereochemistry, exclusively. The supra­molecular hydrogen-bonded network reveals mutual N—HN bonds between adjacent complexes.

The crystallization of a twofold symmetric mol­ecule in a trigonal space group resulted in an atypical formation of solvent-accessible voids in the solid state. Proton-coupled electron-transfer reactions were investigated using a theoretical–experimental approach.

Diffraction analysis of E. coli WrbA crystallized in the presence of FAD yields the highest resolution structure yet reported, but with FMN bound, Met10 oxidized, and a propeller-twisted isoalloxazine ring.