Reaction of a cyclopentadienylcobalt(I) phosphane chelate with trimethylsilyl chloride and some pseudohalides: unanticipated formation of new cyclopentadienylcobalt(II) and (III) chelates

Some reactions of the (phosphanylethyl)cyclopentadienylcobalt(I) chelate complex 1 with trimethylsilyl chloride and some pseudohalides were investigated. Reaction of 1 with trimethylsilyl chloride, azide, isocyanate, and isothiocyanate gave cobalt(II) chelates 2, 3, 4, and 5, some of which were structurally characterized. In contrast to these reactions, treatment of 1 with trimethylsilyl cyanide resulted in the formation of dicyano cobalt(III) chelate 7, which was also structurally characterized. Reaction of 7 followed by oxidation gave a small yield of the tetrametallic complex 8, in which the two cobalt parts of the structure are bridged by an (LiO)2 rhombus.