Electron with low kinetic energy, may attach to some molecules to form negative ions. The study of these reactions which are called electron attachment reaction is important in understanding of many phenomena such as electrical discharge, plasma, laser and atmosphere chemistry. Thus scientists are interested to study on these reactions with different methods. In the most of these methods such as crossed beam, electron swarm and reversal electron attachment usually mass spectrometry is used at low pressure. In this work we study electron attachment to bromo-chloro alkanes by using of ion mobility spectrometry (IMS). The advantage of IMS is capability of working at atmospheric pressure which is similar to condition of these reactions in atmosphere of earth.
