Abstract: 50% effective inhibition concentration 48h-EC50 of 40 substituted benzenes to the algae (Scenedesmus obliquus) was determined. The energy of the lowest unoccupied molecular orbital (ELUMO) was calculated by the quantum chemical method MOPAC6.0-AM1. By using ELUMO and the hydrophobicity parameter log Kow the quantitative structure–activity relationship model ...