- Source: 1-Chloro-3,3,3-trifluoropropene
1-Chloro-3,3,3-trifluoropropene (HFO-1233zd) is the unsaturated chlorofluorocarbon with the formula HClC=C(H)CF3. The compound exists as E- (cis-) and Z- (trans-) isomers. The trans- isomer of this colorless gas is of interest as a more environmentally friendly (lower GWP; global warming potential) refrigerant in air conditioners. It is prepared by fluorination and dehydrohalogenation reactions starting with 1,1,1,3,3-pentachloropropane.