Structures, magnetic properties, and XPS of cyanide-bridged Nd III/Sm III/Gd III–Cr III complexes

Abstract

Synthesis, structural characterization, and spectroscopic and magnetic properties of three new cyano-bridged 3d–4f bimetallic complexes, Ln III(DMF) 4(H 2O) 3Cr III (CN) 6 · nH 2O (Ln = Nd, Sm, Gd), have been described. The Nd–Cr complex crystallizes in the monoclinic P2 1/ n space group with the following unit cell parameters: a = 20.063(7) Å, b = 8.967(4) Å, c = 18.023(6) Å, b = 96.12(3)°, V = 3224(2) Å 3, and Z = 4. The neodymium (III) ion, which adopts anti-prism eight-coordination environment, is linked to the [Cr III(CN) 6] 3− moiety through a bridging cyanide ligand with Nd–N = 2.550(4) Å and Nd–N–C = 164.4(4)°. The variable-temperature (0.5 T at 2–300 K) and variable-field (0–5 T at 2 and 5 K) magnetic measurements reveal that the weak interaction of Gd–Cr complexes differs from that of Nd–Cr and Sm–Cr ones mainly because of the lack of orbital angular momentum. The XPS and diffuse reflectance electronic spectra were also measured to discuss charge transfer transitions concerning π-backdonation from the viewpoint of magneto-optical functions.