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 7-N-(1,9b-dihydrodibenzofuran-4-yl)-2-N-dibenzofuran-4-yl-9,9-dimethyl-2-N,7-N-diphenylfluorene-2,7-diamine .
user
C51H38N2O2
assistant