Cyano-Bridged Bimetallic Complexes of Copper(II) with Nitroprusside. Crystal Structure of [Cu(H2NCH2CH(NH2)CH3)2Fe(CN)5NO] . H2O

Abstract

Five new complexes of compositions [Cu(1,2-pn)₂Fe(CN)₅NO]·H₂O (1,2-pn = propane-1,2-diamine) and [Cu(L)Fe(CN)₅NO]·xH₂O (L = tmen (N,N,N′,N′-tetramethylethane-1,2-diamine), x = 0.5; L = trimeen (N,N,N′-trimethylethane-1,2-diamine), x = 1; L = dien (N-(2-aminoethyl)ethane-1,2-diamine), x = 0; L = medpt (N-(3-aminopropyl)-N-methylpropane-1,3-diamine), x = 2) have been isolated from the reaction mixture of Cu(ClO₄)₂·6H₂O (or CuCl₂·2H₂O), the amine and Na₂ [Fe(CN)₅NO]·2H₂O in water. The complexes have been characterized by infrared and ultraviolet–visible spectroscopies, and magnetic measurements. Single-crystal X-ray structural analysis revealed that the [Cu(1,2-pn)₂Fe(CN)₅NO]·H₂O complex assumes a cyanide-bridged binuclear structure in which iron(II) is six-coordinated by five cyanide ligands and one nitrosyl group (the nitrosyl group lies cis to the bridging cyanide group), while copper(II) is five-coordinated by two propane-1,2-diamine ligands and a bridging cyanide ligand in a distorted tetragonal pyramidal arrangement.