Assembly of an interpenetrating three-dimensional mixed-valence CuII/CuI coordination polymer

A novel cyano-bridged three-dimensional mixed-valence Cu(II)/Cu(I) compound [Cu2(oxpn)][Cu(CN)2]2 (oxpn2− = dianion of N,N′-bis(3-aminopropyl)oxamide) has been synthesized and structurally characterized. Single crystals of 1 formed by diffusion of Cu2(oxpn)Cl2 and K3[Cr(CN)5(NO)] in H2O for two months. The structure of the title compound consists of threefold interpenetrating 3D frameworks. In each 3D network, oxamidato-bridged dimeric [Cu2(oxpn)]2+ units connect 1D polymeric [Cu(CN)2]− anions giving rise to a 3D structure. Room temperature magnetic measurement shows the presence of strong magnetic coupling between the Cu(II) ions. Electronic paramagnetic resonance spectrum measurements show the transitions due to the excited triplet state.