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 3-[3-[4-[3-[9-[4-(2-methylpropyl)phenyl]fluoren-9-yl]phenyl]phenyl]-5-pyridin-3-ylphenyl]pyridine ?
user
C51H40N2
assistant