The complexes [Ni a (Pn) b ] x [Fe(CN)6] y (Pn = 1,3-Diaminopropane): Synthesis and thermolysis

Abstract

The complexes [Ni(Pn)2]2[Fe(CN)6] · 3H2O (I), [Ni3(Pn)5][Fe(CN)6]2 · 9H2O (II), [Ni5(Pn)9][Fe(CN)6]3 · 9H2O (III), and [Ni(Pn)2]3[Fe(CN)6]2 · 6H2O (IV) (Pn = 1,3-diaminopropane) were obtained. Their thermolysis was studied in oxidative (air), reductive (hydrogen), and inert atmospheres (argon) in a temperature range from 20 to 1000°C. Solid and gaseous products of the thermolysis were identified. In air thermolysis, the carbon of the ligands is eliminated as CO and CO2; the solid residues consist of nickel oxide, iron oxides, and the intermetallide Ni3Fe. In hydrogen thermolysis, the ligands are eliminated partially unchanged and partially hydrogenated to ammonia and hydrocarbons. The solid residue at >550°C consists of bimetallic phases with a small carbon impurity. In argon thermolysis, the ligands are eliminated partially unchanged or as fragments of the Pn molecule. The solid residues produced by calcination contain a mixture of metal and oxide phases and 10 to 20% of the initial carbon content.