The synergistic effects of surfactant-surfactant and additive-surfactant based on intermolecular interaction are demonstrated by means of electrochemical measurement and electrodeposition of tin. Three synergistic systems were studied: anionic-cationic surfactant mixture, phthalic acid (PA)-surfactant and rutin (RT)-surfactant. The low critical micelle concentration (CMC) values and improved deposition inhibition obtained from the anionic-cationic mixed surfactant systems indicate that intermolecular electrostatic interactions are an important driving force for the synergistic effect. A comparative study of phthalic acid (PA)-surfactants and rutin (RT)-surfactants indicates that the adsorption behavior of the additives can be varied through the conscious design of the intermolecular interactions between the additive and the anionic-cationic mixed surfactant. The measurements of the carbon contents indicate that the incorporation of organic additives into tin deposits can be improved by the synergistic effects based on the intermolecular interaction of surfactant-surfactant and additive-surfactant. In addition, the synergistic effects based on the intermolecular interaction can affect the morphology of tin deposits. Therefore, it may be a practical way to control the quality of a deposit and the electrodeposition process through a proper design of the intermolecular interaction between the organic additives. (C) 2016 The Electrochemical Society. All rights reserved.