Through-space interactions between face-to-face, center-to-edge oriented arenes: importance of polar–π effects
作者:Franco Cozzi、Rita Annunziata、Maurizio Benaglia、Mauro Cinquini、Laura Raimondi、Kim K. Baldridge、Jay S. Siegel
DOI:10.1039/b208871a
日期:——
Two series of conformationally restricted polycyclic compounds (1â3 and 4â7) have been synthesized as model systems for studying the through-space interactions between face-to-face, center-to-edge (parallel-offset) oriented arenes. These compounds feature different X substituents on one of the interacting rings. By monitoring the variation of the ÎGâ for the rotation around the arylâaryl bond in 1â7 as a function of X by 2D [1H,1H] EXSY NMR spectroscopy, it was found that the barriers increase on passing from electron-donating to electron-withdrawing substituted derivatives. Quantum mechanical calculations [MP2/DVZ (2d,p)//B3LYP/DVZ(2d,p)] gave barrier values and variations in agreement with the experimental data. The results are consistent with a repulsive areneâarene interaction dominated by electrostatic effects.