Theoretical study of molecular interactions of phosphorus ylide with hypohalous acids HOF, HOCl and HOBr

The molecular interactions of phosphorous ylide (PY) and hypohalous acids HOX (X = F, Cl and Br) were investigated using the MP2 method at 6-311++G(2d,2p) basis set. The patterns including non-classical hydrogen bond H⋯C, halogen bond X⋯C, classical hydrogen bonds H⋯X and H⋯O, and F⋯P interactions were found for complex formation between PY and HOX molecules. From the predicted models, stabilities of the X⋯C and H⋯C types complexes are greater than other types. Quantum theories of atoms in molecules (AIM) and natural bond orbitals (NBO) methods have been applied to analyze the intermolecular interactions. Good correlations have been found between the interaction energies (SE), the second-order perturbation energies E(2) and the charge transfer qCT in the studied systems.