Low-energy, adiabatic dissociation pathways of molecular ions can be determined unambiguously by combining IR multiple photon dissociation with a laser based time of flight mass spectrometer_ In this study, we report the sequential dissociation mechanism for the triethylamine cation. The use of laser excitation methods for producing molecular ions under collision free conditions is now well established, and has led to very reasonable speculation concerning the utility of such forms of mass spectroscopy [l-9] _ Certain species can be ionized quite selectively without apparent disturbance of the more abundant background gases [iO,il], spectral signatures can give detailed information about internal state distributions [12], and coherent VW radiation can provide the efficiency and universality required to make the method usable in a large number of circumstances [13,143 _ Often, however, the unusual and intensity dependent cracking patterns of ions produced by multiphoton ionization (MPI) are no: particularly attractive from the point of view of identifying the neutral precursor, or establishing the lowenergy unimolecular reaction pathways of ionized species [ 15 ,163 _ In this brief communication, we describe an experimental method wherein the decomposition of a molecular ion (triethyiamine, hereafter referred to as TEA) is monitored along the low-energy decomposition pathways_ Different daughter ions characteristic of TEA decomposition are produced individually, and are also fragmented via the lowest energy channels. Such processes continue until it is no longer possible to produce or dissociate daughter ions. Molecular ions are produced by MPI, and by