The design, assembly, properties and crystal structure of one-dimensional polymeric cyanide-bridged nickel(II)/nickel(II) complexes

Four novel one-dimensional polymeric complexes {[Ni(pn)2Ni(CN)4]·H2O}n (1), {[Ni(tn)2Ni(CN)4]·H2O}n (2), {[Ni(dien)Ni(CN)4]·(H2O)2}n (3) and {[Ni(trien)Ni(CN)4]·H2O}n (4) (where pn=1,2-diaminopropane, tn=1,3-diaminopropane, dien=diethylenetriamine and trien=triethylenetetraamine) have been synthesized by the reaction of [Ni(L)m]2+ with [Ni(CN)4]2− in aqueous solution. Their properties have been studied by IR spectra, UV–Vis spectra, cyclic voltammetry and variable temperature magnetic susceptibility measurements. The molecular structure of complex 1 has been determined by X-ray diffraction, consisting of a one-dimensional polymeric chain Ni(pn)2NCNi(CN)2CNNi(pn)2 in which the Ni(II) centers are linked by two CN groups. The formation of cyanide bridges is evident from the IR and UV–Vis spectra by appearance of ν(CN) shifts and changes in λmax with respect to the mononuclear parent complex [Ni(CN)4]2−.