Syntheses and structures of two heteronuclear complexes with glycine {[CuEr(Gly)5(H2O)2](ClO4)5•H2O}n and {[Cu2Gd2(Gly)10(H2O)4] (ClO4)10•4H2O}n

Two one-dimensional heterometallic coordination polymers {[CuEr(Gly)(5)(H2O)(2)](ClO4)(5) . H2O }(n)(1) and {[Cu2Gd2 (Gly)(10)(H2O)(4)] (ClO4)(10) . 4H(2)O}(n) (2) (Gly = glycine) were synthesized and structurally and characterized magnetically. Complex I crystallizes in a triclinic space group of P (1) over bar with a = 1. 1769 (2) nm, b = 1.2289(3) nm, c = 1.4452(3) nm, alpha = 89.90(3)degrees, beta = 71.88(3)degrees, gamma = 62.15(3)degrees, and Z = 2. The carboxyl groups of glycine molecules take two coordination modes. The first one acts as a bidentate bridging ligand only. The second is a tridentate bridge that coordinates to three different metal ions. Each erbium ion is eight coordinated, taking a distorted square antiprism arrangement. The copper ion has a square pyramidal coordination polyhedron. The topological structure of complex 2 is similar to complex 1, but there are some disparities in the bond lengths and bond angles. It is also triclinic space group of P (1) over bar with a = 1.2479(3) nm, b = 1.4489(3) run, c 2.0885(4) nm, alpha = 109.56(3)degrees, beta = 93.75(3)degrees, gamma = 93.54(3)degrees, and Z = 2. Variable temperature susceptibility measurements show that there is a weak ferromagnetic interaction between the Gd3+ and Cu2+, ions in complex 2.