Phenalenyl-substituted stilbenes as the basis for spin switches: quantum-chemical modeling

Abstract

Isomers of stilbenes containing phenalenyl substituents in the para - and meta -positions of phenyl rings were studied by means of density functional theory method. Exchange coupling in structures with the trans -form of stilbenes is absent. In the cis -isomer of a meta -substituted compound, the state with a closed electron shell is stabilized due to two-electron multicenter interactions, which is confirmed by CASSCF calculations. The predicted transition between the triplet and singlet states as a result of trans-cis isomerization opens up prospects for using the discovered effect in the development of organic spin switches.