HEPTARFLUOROBUTYRYL FLUORIDE HEPTAFLUOROBUTYRYL FLUORIDE heptafluoro-butanoylfluorid perfluorobutyryl fluoride HEPTAFLUOROBUTYRYL FLUOROIDE Heptafluorobutyric acid fluoride 2,2,3,3,4,4,4-heptafluorobutanoyl fluoride 2,2,3,3,4,4,4-heptafluorobutyryl fluoride