Theoretical and experimental study of lone pair interactions in THF/chloranilic acid system

Crystallization of a multi-component molecular crystal that consists of chloranilic acid with THF as solvate afforded the general formula C₆H₂O₄Cl₂·THF. Its crystal structure is new and reveals new example of cooperative lone pair–π interactions (oxygen of THF to centroid of chloranilic distance of 3.258 Å) beside others (e.g., hydrogen bonding OH···O) with new experimental evidence of receptor/solvent as a lone pair donor. This has been supported by computational methods, mainly, DFT and RIMP2 levels of theory (?48.3 kJ/mol). In addition, several potential curve surfaces are obtained to test the strength and type of every notable interaction in the lattice.