Sarcophagine Ni(II) diperchlorate: synthesis, crystallographic structure, magnetism and high-field EPR

Abstract The [Ni(sar)](ClO 4 ) 2 is characterized by single-crystal X-ray diffraction [S.G. Pmcn , a=8.807(1) A , b=12.410(3) A , c=20.318(4) A , Z =4]. The nickel centers have the octahedral geometry with average dimension Ni–N from 2.06–2.15 A. The magnetic susceptibility of the [Ni(sar)](ClO 4 ) 2 (powder) has been determined by Faraday (4.2–300 K) and SQUID (1.7–300 K). At 293.1 K the gram magnetic susceptibility and the effective magnetic moment are 6.86×10 −6  cm 3  g −1 and 2.94 B.M., respectively. The complex follows a Curie–Weiss law above 10 K up to room temperature. At 77.4 K magnetic susceptibility amounts to χ g =26.6×10 −6 cm 3 g −1 . A single-crystal, W-band EPR study at room temperature allows us to determine the value of the axial anisotropy D=+1.400 cm −1 , g ⊥ =2.143(1) and g ∥ =2.125(1).