SYNTHESIS, STRUCTURE, AND MAGNETISM OF HETEROBINUCLEAR COMPLEX GDCU(OTF)(3)(BDMAP)(2)(H2O)CENTER-DOT-THF

A new heterobinuclear Gd(III)-Cu(II) complex [GdCu] = GdCu(OTf)(3)(bdm ap)(2)(H2O). THF (OTf = SO3CF3) has been prepared by reaction of 1,3-b is(dimethylamino)-2-propanol (bdmapH) with Cu(OCH3)(2) and lanthanide triflate salt Gd(OTf)(3) in a 2:1:1 ratio in THF. Its structure has be en determined by single-crystal X-ray diffraction. [GdCu] crystallizes on an orthorhombic lattice, space group P2(1)2(1)2(1) with Z = 4 and a = 11.023(3) Angstrom, b = 17.555(15) Angstrom, c = 20.212(7) Angstro m, V = 3911(4) Angstrom(3). For 2194 independent reflections with I > 1 sigma(I), full-matrix least squares refinement with anisotropic ther mal parameters for Gd, Cu, S, and O converged to unweighted and weight ed R factors of 0.074 and 0.085, respectively. Gd is coordinated by si x O and two N. Cu is coordinated by two O and two N. Gd and Cu are bri dged by two alkoxo O atoms with separation of 3.311(4) Angstrom. The m agnetic susceptibilities were measured over the temperature range 1.7- 20 K at the field range 0.01-0.5 T. The data of [GdCu] at 0.05 T have been analyzed with the use of a Heisenberg spin Hamiltonian (H) over c ap = <-2J(S)over cap (Gd)>.<(S)over cap (Cu)> giving g = 2.046(2), J = -0.039(3) cm(-1). This shows that Gd-Cu spins are coupled very weakly in the antiferromagnetic manner, though the distance between GD(III) and Cu(II) ions is rather short.