You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 1-butyl-1,2,4,5,6,7-hexahydroinden-2-ide;hafnium(4+);1-methyl-1,2-dihydroinden-2-ide;diiodide by IUPAC nomenclature, provide its molecular formula.
user
C23H28HfI2
assistant