You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule 2-bromo-5-[5-[5-(5-bromo-4-hexylthiophen-2-yl)-4-hexylthiophen-2-yl]-4-hexylthiophen-2-yl]-3-fluoro-4-hexylthiophene ?
user
C40H55Br2FS4
assistant