Synthesis and Structural Characterization of a Series of One-Dimensional Heteronuclear Dirhodium-Silver Coordination Polymers

Herein, we describe the preparation of heteronuclear dirhodium-silver complexes by reaction between molecular Rh(II)-Rh(II) compounds [Rh(2)(μ-O(2)CR)(4)L(2)] (R = Me, Ph (1), CH(2)OEt (2); L = solvent molecules) with paddlewheel structure and PPh(4)[Ag(CN)(2)]. One-dimensional coordination polymers of (PPh(4))(n)[Rh(2)(μ-O(2)CR)(4)Ag(CN)(2)](n) (R = Me (3), Ph (4), CH(2)OEt (5)) formula have been obtained by replacement of the two labile molecules in the axial positions of the paddlewheel structures by a [Ag(CN)(2)](−) bridging unit. The crystal structures of 3–5 display a similar arrangement, having anionic chains with a wavy structure and bulky (PPh(4))(+) cations placed between the chains. The presence of the (PPh(4))(+) cations hinders the existence of intermolecular Ag-Ag interactions although several C-H····π interactions have been observed. A similar reaction between [Rh(2)(μ-O(2)CCMe(3))(4)(HO(2)CCMe(3))(2)] and PPh(4)[Ag(CN)(2)] led to the molecular compound (PPh(4))(2){Rh(2)(μ-O(2)CCMe(3))(4)[Ag(CN)(2)](2)} (6) by replacement of the axial HO(2)CCMe(3) ligands by two [Ag(CN)(2)](−) units. The trimethylacetate ligand increases the solubility of the complex during the crystallization favouring the formation of discrete heteronuclear species.