Abstract
Reaction of Fe(NO3)(3) with 3,6-di(pyrimidin-2-yl)-1,2,4,5-tetrazine (BPymTz) in acetonitrile gives a hepta-coordinated Fe-III complex (1) with the bridging unit 1,2-diiminohydrazido (1,2-dih(2-): -HN-C(R)=N-N=C(R)-NH-) generated in situ from the tetrazine ring-opening of BPymTz. DFT calculations, X-ray diffraction studies and SQUID magnetometry measurements were successfully performed on 1. The crystallography measurement confirms the ring-opening and the substituent's contribution to the rare pentagonal bipyramidal coordination geometry of the metal ions. Magnetic susceptibility measurements on 1 reveal an S = 0 ground state, arising from the antiferromagnetic interaction between the two Fe-III centers (J = -3.02 cm(-1)) within the molecule. (C) 2015 Elsevier Ltd. All rights reserved.