The van der Waals nature of carbon based organic semiconductors (OSCs) offers low cost deposition routes while intermolecular vibrations affect to some extend their charge transport properties, as recently evidenced by our group for different materials. By using experimental inelastic neutron scattering and terahertz spectroscopy, combined with state-of-the-art quantum mechanical simulations, we have for the first time accurately characterized the full-spectrum of low-frequency motions in several OSCs, along with their electron-phonon coupling maps, identifying specific motions detrimental to charge transport in the process (long axis motion modes are the transport killer modes). Therefore, our proposal aims to push our study further and quantify the ability of new organic semiconductors to hamper the long axis motions and validate some new design routes for improved charge transport.