Relationship between the Bond Dipole Moment and Bond Angle of Polar Molecules

The relationship between the bond angle and bond dipole moment is investigated. The atomic dipole moment corrected Hirshfeld (ADCH) charges are used to calculate the bond dipole moment. The electron localization function and its values at the bond critical points are exploited to analyze the bond's electronic structures. Through analyzing the data of a series of covalent compounds formed by the IVA (IVA = C, Si, Ge), VA (VA = N, P, As), VIA (VIA = O, S, Se) and VIIA (VIIA = F, Cl, Br) group elements, it is found that, owing to the repulsion of bond dipole moments, the bond angles of these molecules become larger as their corresponding bond dipole moments increase if the bonds' electronic structures are similar. This observation is also true for the ring molecules studied here, although a stress exists within the ring.