A theoretical study of anion-pi interactions in seven-membered rings

[eng] TURSeveral complexes of tropylium (1) with anions are optimized at the RI-MP2ACHTUNGTRENUNG(full)/6-31++G** level of theory. This binding unit can interact very favorably with anions, and it combines the strength of the electrostatic interaction with the directionality of the anion-p interaction. The complexes of 1 with anions are characterized by means of the Bader theory of "atoms-in-molecules," and the physical nature of the interaction has been analyzed by means of the molecular interaction potential with polarization tool. Experimental evidence of anion-p interactions involving seven-membered rings has been found in the solid state