You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 7,9,9,18,20,20-hexakis-phenyl-3,14-dioxa-7,18-diazapentacyclo[11.7.0.02,10.04,8.015,19]icosa-1(13),2(10),4(8),5,11,15(19),16-heptaene by IUPAC nomenclature, provide its molecular formula.
user
C52H36N2O2
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