Thiazolidine is a heterocyclic organic compound, which is a five-membered saturated ring with a thioether group and an amine group. It is the sulfur analog of oxazolidine. Thiazolidine derivatives have many uses and have a broad spectrum of biological activities. For example, the drug pioglitazone contains a thiazolidine ring. Thiazolidine has three isomers, 2-, 3-, and 4-. Derivatives with a 2-thiazoline ring are the most common.
Fluorene is a polycyclic aromatic hydrocarbon insoluble in water and soluble in many organic solvents. Fluorenes are one of the most important fluorescent molecules with applications in polymers, electronic devices, sensors, and photochromic materials.