Coexistence of ferromagnetic and antiferromagnetic interactions and magnetic ordering in the alternating stacking structure of (BDTA)[Ni(mnt)2]: Possible supramolecular superexchange mechanism

The crystal structure of a charge transfer salt, (BDTA)[Ni(mnt)2], where BDTA is 1,3,2-benzodithiazolyl and mnt is maleonitriledithiolate, was found to consist of alternating stacking columns of S = 0 BDTA+ and S = 1/2 [Ni(mnt)2]−. Magnetic and thermodynamic measurements revealed the coexistence of ferromagnetic and antiferromagnetic interactions and antiferromagnetic ordering at 3.4 K. The observed ferromagnetic coupling was interpreted in terms of a supramolecular superexchange mechanism.