Tetracarbonatodiruthenium Fragments and Lanthanide(III) Ions as Building Blocks to Construct 2D Coordination Polymers

Two-dimensional coordination polymers of [Pr(DMSO)(2)(OH(2))(3)][Ru(2)(CO(3))(4)(DMSO)(OH(2))]·5H(2)O (Prα) and [Ln(OH(2))(5)][Ru(2)(CO(3))(4)(DMSO)]·xH(2)O (Ln = Sm (Smβ), Gd (Gdβ)) formulae have been obtained by reaction of the corresponding Ln(NO(3))(3)·6H(2)O dissolved in dimethyl sulphoxide (DMSO) and K(3)[Ru(2)(CO(3))(4)]·4H(2)O dissolved in water. Some DMSO molecules are coordinated to the metal atoms reducing the possibilities of connection between the [Ru(2)(CO(3))(4)](3−) and Ln(3+) building blocks giving rise to the formation of two-dimensional networks. The size of the Ln(3+) ion and the synthetic method seem to have an important influence in the type of two-dimensional structure obtained. Slow diffusion of the reagents gives rise to Prα that forms a 2D net that is built by Ln(3+) ions as triconnected nodes and two types of Ru(2)(5+) units as bi- and tetraconnected nodes with (2-c)(3-c)(2)(4-c) stoichiometry (α structure). An analogous synthetic procedure gives Smβ and Gdβ that display a grid-like structure, (2-c)(2)(4-c)(2), formed by biconnected Ln(3+) ions and two types of tetraconnected Ru(2)(5+) fragments (β structure). The magnetic properties of these compounds are basically explained as the sum of the individual contributions of diruthenium and lanthanide species, although canted ferrimagnetism or weak ferromagnetism are observed at low temperature.