<unk> , Co(C5H5)2, is known as bis(cyclopentadienyl)cobalt(II) or even "bis Cp cobalt."  This dark purple compound is solid at room temperature that sublimes at 40 °C in a good vacuum, ca. 0.1 mm.<unk>  was discovered shortly after ferrocene, the first "metallocene."  The compound must be handled and stored in the absence of air due to the ease with which it reacts with O2.<unk>  is prepared by the reaction of sodium cyclopentadienide, NaC5H5, with anhydrous CoCl2 in THF solution.  Sodium chloride is generated, and the organometallic product is usually purified by vacuum sublimation.
Cobaltocene
Hermaphrodite
Lime 
Chromate
Cilium
Opium
Bite
Diosmectite