A theoretical study of electronic structures and intermolecular magnetic interactions for spiro-biphenalenyls

In order to inquire into the mechanism of the change in the magnetism of spiro-biphenalnyls, intermolecular magnetic interaction is investigated in terms of the effective exchange integral of the Heisenberg model for dimeric pairs of diethyl-substituted spiro-biphenalenyl. Variation of the magnetic interaction with respect to temperature is evaluated for X-ray crystallographic structures at several temperature points by Kohn-Sham hybrid-DFT. The intermolecular magnetic interactions were calculated for the π-dimers to be antiferromagnetic at each temperature.