[Cu(C8H16N4O2)0.5[N(CN)2]]n, a novel ladder-like coordination polymer.

A new polymeric copper complex, viz. catena-poly[[[mu-N,N'-bis(3-aminopropyl)oxamidato-kappa6N,N',O:N",N"',O']dicopper(II)]-di-mu-dicyanamido-1:1'kappa2N1:N5;2:2'kappa2N1:N5], [Cu2(C8H16N4O2)(C2N3)2]n or [Cu(oxpn)0.5[N(CN)2]]n [where H2oxpn is N,N'-bis(3-aminopropyl)oxamide], has been synthesized by the reaction of Cu(oxpn), [Cu(ClO4)2].6H2O and NaN3. In the crystal structure, the Cu atom is five-coordinate and has a square-pyrimidal (SP) configuration. In the polymer, dicyanamide (dca-) groups link CuII cations in a mu-1,5-bridging mode, generating novel ladders in which each step is composed of dimeric [Cu2(oxpn)]2+ cations. Abundant hydrogen bonds connect the polymer ladders into a two-dimensional network structure.