Bis(boryl)metallocenes. 1. 1,1‘-Bis(diisopropylboryl)cobaltocenium Cation: A Novel Anion-Binding Ligand

Three situations are observed when the new cobaltocene derivative Co(C 5 H 4 BPr i 2 ) 2 ( 2 ) is oxidized. The cobaltocenium salt [ 2 ]PF 6 ( 3 ) is obtained with [FeCp 2 ]PF 6 as oxidant. With Cu(OH) 2 the inverse chelate [ 2 ]OH ( 4 ) with a μ-OH group bridging the two boron centers is formed. Oxidation with C 2 Cl 6 gives a zwitterionic chloride ( 5 ) with a trigonal and a quaternized boron center; in solution 5 is fluxional.