Intermolecular complexes of halocyclopropenone derivatives with the hypohalous acids HOF, HOCl, HOBr, and HOI

The intermolecular interactions between halocyclopropenone derivatives (HC$_{3}$OX; X $=$ I, Br, Cl, and F) and hypohalous acids (HOY; Y $=$ I, Br, Cl, and F) were studied via the MP2 method utilizing the aug-cc-pVTZ and aug-cc-pVTZ(-PP) basis sets. The three types of complexes were hydrogen bonds, halogen bonds, and complexes containing both hydrogen and halogen bonds. The results obtained indicated that interactions in the Type 1 complexes were stronger than those in Types 2 and 3. The H-O bonds revealed red shifts with complex formation in Types 1 and 2. The O-Y bonds displayed red shifts in the Type 3 and blue shifts in the Type 2 structures. Molecular electrostatic potential, quantum theory of atoms in molecules, and natural bond orbital methodologies were used to analyze these interactions.