| Abstract
| - The reactions of tetrahedral clusters [HMCo3(CO)12] (M = Ru or Fe) with phosphine selenides afford two types of clusters: [MCo2(μ3-Se)(CO)9-xLy] (x = y = 1, 2, with L = monodentate ligand; x = 2, 4, and y = 1, 2, with L = bidentate ligand) (M = Fe, Ru) and [HMCo3(CO)12-xLy]. The former results from PSe bond cleavage leading to a selenium transfer to the metal centers, while the latter type derives from simple substitution of one or two carbonyl groups by a deselenized phosphine ligand. In contrast, no Se transfer to the metal core is observed when the anionic clusters [MCo3(CO)12]- are used as precursors.
- The reactivity of [HMCo3(CO)12] and [Et4N][MCo3(CO)12] (M = Fe, Ru) toward phosphine selenides such as Ph3PSe,Ph2P(Se)CH2PPh2, Ph2(2-C5H4N)PSe, Ph2(2-C4H3S)PSe, and Ph2{(2-C5H4N)(2-C4H2S)}PSe has been studied withthe aim to obtain new selenido-carbonyl bimetallic clusters. The reactions of the hydrido clusters give two mainclasses of products: (i) triangular clusters with a μ3-Se capping ligand of the type [MCo2(μ3-Se)(CO)9-xLy] resultingfrom the selenium transfer (x = y = 1, 2, with L = monodentate ligand; x = 2, 4, and y = 1, 2, with L =bidentate ligand) (M = Fe, Ru) and (ii) tetranuclear clusters of the type [HMCo3(CO)12-xLy] obtained by simplesubstitution of axial, Co-bound carbonyl groups by the deselenized phosphine ligand. The crystal structures of[HRuCo3(CO)7(μ-CO)3(μ-dppy)] (1), [MCo2(μ3-Se)(CO)7(μ-dppy)] (M = Fe (16) or Ru (2)), and [RuCo2(μ3-Se)(CO)7(μ-dppm)] (12) are reported [dppy = Ph2(2-C5H4N)P, dppm = Ph2PCH2PPh2]. Clusters 2, 12, and 16 are thefirst examples of trinuclear bimetallic selenido clusters substituted by phosphines. Their core consists of metaltriangles capped by a μ3-selenium atom with the bidentate ligand bridging two metals in equatorial positions. Thecore of cluster 1 consists of a RuCo3 tetrahedron, each Co−Co bond being bridged by a carbonyl group and onefurther bridged by a dppy ligand. The coordination of dppy in a pseudoaxial position causes the migration of thehydride ligand to the Ru(μ-H)Co edge. In contrast to the reactions of the hydrido clusters, those with the anionicclusters [MCo3(CO)12]- do not lead to Se transfer from phosphorus to the cluster but only to CO substitution by thedeselenized phosphine.
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