You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[1-(2,6-dimethylphenyl)imidazol-2-yl]-1-methyl-5H-benzimidazol-5-ide;iridium The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H17IrN4-
assistant