The azidopentacyanoferrate(III) ion as a tecton in constructing heterometallic complexes: Synthesis, crystal structure and magnetic properties of [Mn(valphen)(H 2O) 2] 2[(H 2O)(valphen)Mn(μ-CN)Fe(CN) 4(N 3)]·8H 2O

Abstract

By employing the common precursor Na 3[Fe(CN) 5(NH 3)]·3H 2O in a new synthetic approach, the azidopentacyanoferrate(III) ion has been isolated and structurally characterized as (Ph 4As) 2[Na(H 2O) 4][Fe(CN) 5(N 3)] 1. In order to confirm its building block ability, compound 1 has been reacted with the mononuclear complex [Mn(valphen)(H 2O) 2]ClO 4 (H 2valphen represents the Schiff base resulting from the condensation of o-vanillin with 1,2-phenylenediamine in a 2:1 M ratio) to afford the new Mn III–Fe III heterometallic system [Mn(valphen)(H 2O) 2] 2[(H 2O)(valphen)Mn(μ-CN)Fe(CN) 4(N 3)]·8H 2O 2. The crystal structure of compound 2 reveals a supramolecular assembly generated by [(H 2O)(valphen)Mn(μ-CN)Fe(CN) 4(N 3)] 2− dianions and discrete [Mn(valphen)(H 2O) 2] + counterions. The dynamic magnetic measurements of compound 2 point to a slow relaxation of the magnetization.