You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance ethane;3-(2-fluoro-3-phosphanylphenyl)-1-(2,2,2-trifluoroethyl)-5,6-dihydro-2H-azepin-7-one .
user
C18H26F4NOP
assistant