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What is the molecular formula of the compound with this IUPAC name 18-[3-(9-phenylcarbazol-3-yl)carbazol-9-yl]-21-oxa-16,19-diazapentacyclo[12.7.0.02,7.08,13.015,20]henicosa-1(14),2,4,6,8,10,12,15,17,19-decaene ?
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C48H28N4O
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