Jm. Holland et al., An unusual abrupt thermal spin-state transition in [FeL2][BF4](2) [L=2,6-di(pyrazol-1-yl)pyridine], CHEM COMMUN, (6), 2001, pp. 577-578
The complex [Fe((LH)-H-1)(2)][BF4](2) exhibits an abrupt thermal spin-cross
over which may be mediated by an order-disorder transition of the BF4- anio
ns.