2 6 dichloroindophenol conjugate base July 8, 2019 16 32 64 128 2 6 dichloroindophenol conjugate base resonance structures 2 6-dichlorophenolindophenol 2 6-dichlorphenol 2 6-dichloroindophenol density 2 4 dichlorphenol 2 6-dichlorophenolindophenol sigma