Cannabis October 12, 2016 thcscience_admin Cyclopentadienyl can refer to Cyclopentadienyl anion, or cyclopentadienide, [C5H5]− Cyclopentadienyl ligand Cyclopentadienyl radical, [C5H5]• Cyclopentadienyl cation, [C5H5]+ See also[edit] Pentadienyl