Hydrophobic interaction and solvatochromic shift of benzene in water

Monte Carlo simulations of one and two benzene molecules in water have been performed to analyze the hydrophobic hydration and hydrophobic interaction effects. Also, Monte Carlo structures have been used in the quantum mechanical calculations of the red shift of the B2u(π−π∗) band of benzene in water and the role of hydrophobicity analyzed. It has been found, on average, that the water molecule closet to benzene has one of the OH bonds tangential to the benzene plane; the water-induced effect essentially doubles the benzene-benzene interaction and hydrophobicity has a small, but non-negligible, effect on the red shift of the first absorption band of benzene in water.