Metallo‐Ligand Based 3d/4f Coordination Polymers: Synthesis, Structure and Magnetic Properties

Employment of N,N '-bis(2-hydroxy-4-carboxyphenyl)oxalamide (H6L) in Cu2+ chemistry afforded the mononuclear complex (Et4N)(4)[CuL] . 13H(2)O (A) which comprises a square planar [CuL](4-) complex with several O donor atoms in its periphery. The 1 : 1 reaction between complex A and Ln(NO3)(3) . xH(2)O (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er and Yb, x=6 or 9) in 1 : 4 mixture of ethanol/water in the presence of excess of KCl yielded two families of isomorphous 3d/4f coordination polymers, namely (Et4N)(0.5)[K-0.5(H2O)Ln(H2O)(4)(CuL)] . 3H(2)O [Ln=La(1), Ce(2), Pr(3), Nd(4), Sm(5), Eu(6) and Gd(7)] and [K(H2O)Ln(H2O)(4)(CuL)] . .6H(2)O [Ln=Tb(8), Dy(9), Ho(10), Er(11) and Yb(12)]. The crystal structures of 2-4 revealed the presence of 3D coordination polymers while the crystal structure of 9 the presence of a 2D coordination polymer. In both 3d/4f families, complex A retains its original structure and serves as a "metallo-ligand". The magnetic properties of 2-4, 7-9, 11 and 12 are discussed.