4F-PV9 with a lupac name of 1-(4-fluorophenyl)-2-(pyrrolidin-1-yl)octan-1-one is related to a-pvp structurally and is a chain extended homologue. The chemical formula for 4F-PV9 is C18H26FNO. It has an exact mass of 291.20 and a molecular weight of 291.40. The compound is a white or off-white crystalline powder with a purity of 99.8%.