Halogen bond in (CH3)nX (X=N, P, n=3; x=s, n=2) and (CH3)nXO (X = N, P, n=3; X=S, N=2) adducts with CF3I. Structural and energy analysis including relativistic zero-order regular approximation approach in a density functional theory framework

Density functional theory (DFT) calculations on the geometry and bonding energy of the X - - - I intermolecular interaction of CF3I and (CH3)(sub n)X and (CH3)(sub n)XO are reported. All the adducts with the oxides as donors show a weaker interaction with CF3I than the relative donor without oxygen except the CF3I - - - ON(CH3) adduct, which has a stronger interaction.