Synthesis and characterization of two novel isostructural polymeric 1D mono-halo-bridged octahedral copper (II) chains with a diaza-diamine ligand

Two novel isostructural (Π = 0.0045, I_v = 93.292) one-dimensional mono-halo-bridged octahedral copper (II) polymeric complexes [Cu(L)Cl]_n(ClO₄)_n (1) and [Cu(L)Br]_n(ClO₄)_n (2) (L = 1,9-diamino-5-methyl-5-nitro-3,7-diazanonane) were prepared and characterized by CHN, IR, EPR and magnetic moment studies under a tetra coordinating (diaza-diamine type) ligand environment. The X-ray structure analysis indicates that in both 1 and 2, independent consecutive [Cu(L)X]⁺ (X = Cl or Br) cations with crystallographic C_s symmetry propagate through the a glide plane of the orthorhombic space group Pnma to give the polymeric chain structure along the a axis. In 1, the Cu-Cl bond length is 2.740 which under bridging condition elongates to 3.024 and the bridging angle, Cu-Cl-Cu, is 164.9 while parameters for 2 are 2.961(2), 3.074(2) and 157.4(5), respectively. Each monomeric unit in both the complexes is under extensive intra and inter-molecular hydrogen bonding, leading to three dimensional structures.