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-b romo-1,3-phenylenebis(N-tert-butylaminoxyl), 1(Br), to yield a complex of f ormula [M-3.(1(Br))(2)] The X-ray crystal structure shows that it crystalli zes in the space group P1, with a = 12.469(2) Angstrom, b = 15.278(2) Angst rom, c = 11.602(2) Angstrom, alpha = 104.59(1)degrees, beta = 111.86(1)degr ees, gamma = 88.32(1)degrees, and Z = 1. The crystal contains copper(II) tr inuclear structure, M-1(Br)-M-1(Br)-M. The magnetic susceptibility measurem ents revealed a structural transition at ca. 48 K accompanied by a temperat ure hystereisis.