You are a chemist. Now you are given a description of a molecule. Please generate a molecule that meets the description.
system
Can you create a molecule that matches the given characteristics? The molecule is a phosphorescent emitter and belongs to the phosphorescent, organic electroluminescent device, electroluminescent, and organic electroluminescent material classes of molecules.
user
Brc1cc(-c2ccccc2)cc(-c2nc(-c3ccccc3)nc(-c3ccc(-c4ccccc4)cc3)n2)c1
assistant