Synthesis and structure of 3-fluorenyl-3-cobalta-1,2-dicarba-closo-nonaborane(11), 3-(η5-C13H9)-3,1,2-closo-CoC2B9H11

A Cobaltocenium Complex of Dibenzo[c,g]fluorenide and Its Structural and Electrochemical Properties

“…However, these compounds had been characterized solely by elemental analysis, mass spectrometry, and infrared spectroscopy. η 5 -Coordination of Flu − to a cobalt center was finally confirmed in 1992 by the publication of the solid-state structure of (η 5 -Flu)(η 5 -carborane)cobaltocene . Recent examples of fully characterized cobalt triple-decker complexes containing η 5 -Flu − ligands were reported by Schneider et al in 2007 .…”

What Can We Learn from the Crystal Structures of Metallacarboranes?

“…In the analogous iron species [3-(C 9 H 7 )-closo-3,1,2-FeC 2 B 9 H 11 ] the two rings are eclipsed and the ring-junction C atoms sit directly above the cage C atoms [34], rationalised by a significantly greater distance between the rings in the iron complex (3.23 Å) compared to that in the cobalt complex (3.09 Å). One η 5 -fluorenyl metallacarborane is known [35]. In the fluorenyl ligand are two pairs of ring-junction C atoms, and the observed orientation in [3-(C 13 H 9 )-closo-3,1,2-CoC 2 B 9 H 11 ], Figure 8b, is that which maximises the adjacency of ring-junction and carborane C atoms, as predicted by STE arguments.…”

“…In the analogous iron species [3-(C9H7)-closo-3,1,2-FeC2B9H11] the two rings are eclipsed and the ringjunction C atoms sit directly above the cage C atoms [34], rationalised by a significantly greater distance between the rings in the iron complex (3.23 Å) compared to that in the cobalt complex (3.09 Å). One η 5 -fluorenyl metallacarborane is known [35]. In the fluorenyl ligand are two pairs of ring- In indenyl, naphthalene, and related η-bonded ligands the π-atomic orbitals of the ring-junction C atoms are simultaneously involved in two aromatic systems and consequently are relatively weakly bound to the metal atom (small STE) compared to the non-ring-junction C atoms.…”