1 1 2 2 tetrafluoroethane structure July 8, 2019 16 32 64 128 1 2 dibromo 1 1 2 2 tetrafluoroethane structure 1 1 2 2-tetrafluoroethane 1 1 2 2-tetrafluoroethyl-2 2 3 3-tetrafluoropropyl ether