A Neutral Dy(II) Bis(amide): Synthesis, Magnetism, and a P₄²– Complex

Reaction of DyCl3 with KNHAr*, where Ar* = 2,6-Ar2C6H3 and Ar = 2,4,6-iPr3C6H2, results in the formation of ClDy(NHAr*)2, which can be reduced with KC8 in THF to room temperature stable dysprosium(II) Dy(NHAr*)2, where Ar rings of the NHAr* ligand chelate and bind to the metal center to give a black sandwich complex. The redox potential for the reversible Dy2+/3+-couple was found to be -1.094 ± 0.001 V with respect to FeCp2+/0 as 0.000 V. The complex was examined by CASSCF calculations, which suggest the non-Kramer's ion has an 4f95d1-configuration with little to no s-orbital participation. The reaction of Dy(NHAr*)2 with CNtBu results in assumed tert-butyl radical loss along with formation of the isocyanide CN-Dy(NHAr*)2, which shows a strong absorption in the IR spectrum at 2052 cm-1 assigned to the C-N stretch. Reaction of P4 with Dy(NHAr*)2 gave crystals of salt {Dy(NHAr*)2}+{(P4)Dy(NHAr*)2}-, which shows both η2-P42- and η4-P42- ligands in the solid state.