Charge transfer salts of BO with paramagnetic isothiocyanato complex anions: (BO)[M(isoq)2(NCS)4]; M=Cr-III or Fe-III, isoq=isoquinoline and BO= bis(ethylenedioxo)tetrathiafuivalene

摘要

The preparation, X-ray structures and magnetic properties of two isostructural new charge transfer salts: (BO)[M (isoq)(2)(NCS)(4)]; M=Cr-III (1), Fe-III (2) and isoq = isoquinoline are reported. Their structure consists of alternate organic and inorganic layers, each layer being formed by mixed columns of BO radical cations and paramagnetic metal complex anions. There are short intermolecular contacts between donor and anion (S2(anion) (. . .) S4BO < 3.5 Angstrom) and between adjacent BO molecules (O (. . .) O1 < 3.2 Angstrom). The two compounds are insulators. ESR measurements show single signal without separating the donor and anion spins. The magnetic measurements obey the Curie-Weiss law and revealed dominant antiferromagnetic interactions between anion spin and donor spin, but long-range magnetic ordering did not occur down to 2K. This is directly related to structural reasons which were deduced from a comparison of the title compounds with other 1:1 salts containing same anion complexes and different donors. (C) 2002 Elsevier Science (USA). [References: 34]