Reaction of FcCCo3(CO)9 with 2,3-bis(diphenylphosphino)maleic anhydride (bma). X-ray diffraction structure and redox properties of

Ligand substitution in HC(O)CCo3(CO)9 with 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd): Diphosphine ligand fluxionality, decarbonylation of the formyl moiety and competitive P–Ph bond cleavage reactivity

“…Samples of cluster 2 that were cycled several times over the temperature range of 187-298 K afforded 31 P NMR spectral changes consistent with a reversible equilibrium between the isomeric bpcd clusters, as depicted below in Eq. (2) and previously demonstrated by us for PhCCo 3 (CO) 7 (bma) [1]. The K eq value at 187 K is 1.22 in favor of the bridging isomer.…”

“…Due the relative instability of 4, the product was spectroscopically characterized in solution. IR (CH 2 (2) 11.5588 (9) 10.395 (1) …”

“…Coordination of the diphosphine ligands 2,3-bis(diphenylphosphino)maleic anhydride (bma) and 4,5-bis(diphenylphosphino)-4-cyclopenten-1, 3-dione (bpcd) to the tetrahedrane clusters RCCo 3 (CO) 9 [R = Ph, Fc, Me, Cl] affords the corresponding diphosphine-substituted clusters RCCo 3 (CO) 7 (P-P) [1][2][3][4]. This genre of trimetallic clusters continues to command our attention due to the novel reactivity that these systems exhibit as a result of the ancillary diphosphine ligand.…”

“…Scheme 1 summarizes the known reactivity pathways for the tricobalt cluster family, where three different modes of reaction have been found. When the capping RC group is Ph or ferrocenyl (Fc), the RCCo 3 (CO) 7 (P-P) clusters decompose with the formation of the benzylidene-and ferrocenylidene-capped clusters Co 3 (CO) 6 [l 2 ,g 2 ,g 1 -C(R)C@C(PPh 2 )C(O)XC(O)]-(l 2 -PPh 2 ) [1,2], while the Me-and Cl-capped derivatives display gross decomposition under comparable thermolysis conditions [5]. The last manifold for cluster/ligand activation involves the clusters HC(O)CCo 3 (CO) 7 (P-P) and HCCo 3 (CO) 7 (P-P), whose reaction chemistry serves as the basis of this report.…”

Ligand substitution in the tetrahedrane clusters RCCo2Mo(η5-indenyl)(CO)8 with 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd): Influence of the carbyne and indenyl ligands on the stability of the substitution products and X-ray diffraction structures of HCCo2Mo(η5-indenyl)(CO)6(μ-bpcd) and CoMo(η5-indenyl)(μ-CPh)(CO)2(μ-bpcd)Cl

“…Accordingly, we have begun to devote a greater amount of our attention to the examination of the chemistry associated with the bpcd ligand. These particular ligands, whose structures are depicted below, react with RCCo 3 (CO) 9 to give the corresponding diphosphinesubstituted clusters RCCo 3 (CO) 7 (P-P) [1][2][3][4][5]. The RCCo 3 (CO) 7 (P-P) clusters are of interest as they display dynamic, non-dissociative chelate-to-bridge diphosphine isomerization about the cluster polyhedron and facile cluster/diphosphine activation at ambient temperatures.…”