You are a chemist. Now you are given a description of a molecule. Please generate a molecule that meets the description.
system
Come up with a molecule based on the description: The molecule is photochromic.
user
COc1ccc(C2(c3ccc(OC)cc3)OC3C4=CC=COC4=c4ccccc4=C3C3=C2C=CCC3=O)cc1
assistant