On-surface π-conjugated 1D polymers, like graphene nanoribbons, have emerged as a class of promising materials. On-surface chemical properties of 9,9′-bianthryl molecules are widely developed as they can be used as starting building blocks to provide graphene nanoribbons. Here, we propose to investigate the chemical behavior of 10,10′-disubstituted-9,9′-bianthryl molecules on Cu(111) and Au(111) surfaces by using scanning tunneling microscopy under ultra-high vacuum. We demonstrated that the balance between molecule-molecule interaction, molecule-substrate interaction, and molecular rearrangement, drastically alter the chemical properties of the adsorbed molecule by thermal annealing.