Hybrid cluster-cages formed via cyanometalate condensation: Cs subset Co(4)Ru(6)S(2)(CN)(12), Co(4)Ru(9)S(6)(CN)(9), and Rh(4)Ru(9)S(6)(CN)(9) frameworks.

Abstract

Condensation of cyanometalates and cluster building blocks leads to the formation of hybrid molecular cyanometalate cages. Specifically, the reaction of [Cs subset [CpCo(CN)(3)](4)[CpRu](3)] and [(cymene)(2)Ru(3)S(2)(NCMe)(3)]PF(6) produced [Cs subset [CpCo(CN)(3)](4)[(cymene)(2)Ru(3)S(2)][CpRu](3)](PF(6))(2), Cs subset Co(4)Ru(6)S(2)(2+). Single-crystal X-ray diffraction, NMR spectroscopy, and ESI-MS measurements show that Cs subset Co(4)Ru(6)S(2)(2+ ) consists of a Ru(4)Co(4)(CN)(12) box fused with a Ru(3)S(2) cluster via a common Ru atom. The reaction of PPN[CpCo(CN)(3)] and 0.75 equiv of [(cymene)(2)(MeCN)(3)Ru(3)S(2)](PF(6))(2) in MeCN solution produced [[CpCo(CN)(3)](4)[(cymene)(2)Ru(3)S(2)](3)](PF(6))(2), Co(4)Ru(9)S(6)(2+). Crystallographic analysis, together with NMR and ESI-MS measurements, shows that Co(4)Ru(9)S(6)(2+ ) consists of a Ru(3)Co(4)(CN)(9) "defect box" core, wherein each Ru is fused to a Ru(3)S(2) clusters. The analogous condensation using [CpRh(CN)(3)](-) in place of [CpCo(CN)(3)](-) produced the related cluster-cage Rh(4)Ru(9)S(6)(2+). Electrochemical analyses of both Co(4)Ru(9)S(6)(2+) and Rh(4)Ru(9)S(6)(2+) can be rationalized in the context of reduction at the cluster and the Co(III) subunits, the latter being affected by the presence of alkali metal cations.