The Sn-Cl chemical bond of four organotin halides (MeSnCl, EtSnCl, BuSnCl, and PhSnCl) was studied by using relativistic density functional theory in combination with a quantitative energy decomposition analysis to explain the formation of charged species. The σ orbital is the dominant contributor to the stabilization of the Sn-Cl bond, and the π-orbital interactions also have a significant contribution to the stabilization of PhSn cation when the aromatic groups are bonded to the tin atom. The aromaticity of the phenyl groups delocalizes the positive charge, donating electrons to tin atom by conjugation. Although MeSnCl and PhSnCl are constituted by groups which the size of the substituents is different, the interaction energies obtained with the energy decomposition analysis present similar values, which also occur with the thermodynamic parameters. Graphical abstract Organotin compounds have widely studied as a potential antitumoral agent. The mechanism in triorganotin compounds includes the formation of cation species, RSn. This article studies the influence of the R groups on the rupture of Sn-Cl bond using the fragment analysis and quantitative energy decomposition analysis.