Syntheses, structures, and magnetic properties of 3d–4f heterometallic complexes constructed from pyrazole-bridged CuIILnIII dinuclear units

A series of pyrazole-bridged heterometallic 3d–4f complexes, [CuDy(ipdc)2(H2O)4] · (2H2O)(H3O+) (1) and [CuLn(pdc)(ipdc)(H2O)4] · H3O+ (Ln = Ho (2), Er (3), Yb (4); H3ipdc = 4-iodo-3,5-pyrazoledicarboxylic acid; H3pdc = 3,5-pyrazoledicarboxylic acid), {[Cu3Ln4(ipdc)6(H2O)16] · xH2O}n (Ln = Sm (5), x = 8.5; Ln = Eu (6), x = 7; Ln = Gd (7), Tb (8), x = 9), have been synthesized and structurally characterized. Ligand H3ipdc was in situ obtained by iodination of ligand H3pdc. Complexes 1–4 are pyrazole-bridged heterometallic dinuclear complexes, and 2–4 are isostructural. Complexes 5–8 are isostructural and comprised of an unusual infinite one-dimensional tape-like chain based on pyrazole-bridged heterometallic dinuclear units. The magnetic properties of compounds 1–4, 7 and 8 have been investigated through the magnetic measurement over the temperature range of 1.8–300 K.