A threshold for charge transfer in aromatic interactions? A quantitative study of pi-stacking interactions.
[structure: see text] Attractive interactions between substituted arenes in the parallel displaced configuration have been quantitatively studied using triptycene-derived molecular conformational reporters. Charge-transfer bands are observed for models where the interactions are between strong donor and acceptors. Substituent effects on the strength of the aromatic interaction follow opposite trends for strongly electron-deficient arenes and mildly perturbed arenes. The free energy of interactions for models with strong electron donors and acceptors does not follow a linear correlation in the Hammett plot. Electrostatic models alone do not account for the nonlinearity of the free energy-substituents plot.
Gung
Benjamin W
BW
Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, USA. gungbw@muohio.edu
Patel
Mehul
M
Xue
Xiaowen
X
D004583:Electrons; D006841:Hydrocarbons, Aromatic / Q000737:chemistry*; D008958:Models, Molecular; D055672:Static Electricity
D006841:Hydrocarbons, Aromatic