Angewandte Chemie International Edition
Intense colorations and new charge-transfer absorption bands are observed upon addition of a halide (Cl−, Br−, I−) to neutral organic π acceptors with electron-deficient olefinic and aromatic centers. These phenomena results from noncovalent anion–π interactions (shown schematically), which were confirmed by X-ray crystallography.
Rosokha, Yaroslav S.; Lindeman, Sergey; Rosokha, Sergiy V.; and Kochi, Jay K., "Halide Recognition through Diagnostic “Anion–π” Interactions: Molecular Complexes of Cl−, Br−, and I− with Olefinic and Aromatic π Receptors" (2004). Chemistry Faculty Research and Publications. 580.
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