Pyrazine-N,N′-dioxide/tetracyanoethylene electron donor–acceptor bonding and the effect of donor steric demand and symmetry on the cocrystal assembly

The synthesis of a sterically hindered pyrazine dioxide electron donor (2,5-diethyl-3,6-dimethylpyrazine-N,N′-dioxide) and its cocrystallization with tetracyanoethylene (TCNE) are reported. The resulting DA assembly in the cocrystal is compared to that observed for a smaller pyrazine-N-oxide donor. Increased steric demand and lower donor symmetry yield a new, more complex two-dimensional DA assembly with slightly longer DA bonds and higher TCNE content in the cocrystal.