The modern technologies, especially in the field of chemical engineering and energy related applications, are constant search for new tunable and adaptable materials. Such task demands for a more rational approach to the chemical design of new molecular systems. In many cases the structural methods of investigations are not sufficient since the base functionality is governed by the mobility of selected molecular components. Hence the knowledge behind molecular mobility mechanisms is essential. In my talk I will give a brief overview of how the combined use of solids state ²H NMR and QENS  can provide and efficient toolbox for probing molecular mobility in complex confined states. I will focus on two characteristic examples of the hydrocarbons diffusion in microporous metal-organics frameworks and protons migration in solid proton conductors and hydrates.