Heteropolymetallic assemblies constructed from homometallic coordination polymers and paramagnetic metal-containing anions.: Synthesis, crystal structure and magnetic properties of [Mn(4,4′-bipyridine-N,N′-dioxide) (H2O)4][Cr(bipy)(C2O4)2]2•8H2O

The reaction of the Mn2+ (aq) and [Cr(bipy)(C2O4)(2)](-) (aq) ions with 4,4'-bipyridine-N,N'-dioxide leads to a heteropolymetallic system, [Mn(4,4'-bipyridine-N,N'-dioxide) (H2O)(4)][Cr(bipy)(C2O4)(2)](2) . 8H(2)O (1) The crystal structure of 1 consists of one-dimensional chains, (1)(infinity)[Mn(4,4'-bipyridine-N,N'-dioxide) (H2O)(4)](n)(2n+), with Mn(II) ions bridged by 4,4'-bipyridine-N N'-dioxide ligands. The infinite homometallic chains are interconnected through hydrogen bonds with the water molecules and the [Cr(bipy)(C2O4)(2)](-) anions. The cryomagnetic measurements of compound 1 reveal weak anti-ferromagnetic interactions between the manganese(II) ions within the chain (J= -1.2 cm(-1)). (C) 2001 Published by Elsevier Science B.V. All rights reserved.