Synthesis and Magnetic Properties of Bis(Hexafluoroacetylacetonato)Copper(II) Complex with 5-Bromo-1,3-Phenylenebis(N-tert-Butylaminoxyl) as a Bridging Ligand

Bis(hexafluoroacetylacetonato)copper(II), Cu(hfac)2 (= M) reacts with 5-bromo-1,3-phenylenebis(N-tert-butylaminoxyl), 1 Br to yield a complex of formula [M 3·(1 Br)2]. The X-ray crystal structure shows that it crystallizes in the space group P2, with a = 12.469(2) Å, b = 15.278(2) Å, c= 11.602(2) Å, α = 104.59(1)°;, β = 111.86(1)°;, γ= 88.32(1)°;, and Z= 1. The crystal contains copper(II) trinuclear structure, M-1 Br-M-1 Br-M. The magnetic susceptibility measurements revealed a structural transition at ca. 48 K accompanied by a temperature hystereisis.