In the earliest phases of star-forming clouds , stable molecular species , such as CO , are important coolants in the gas phase .
Depletion of these molecules on dust surfaces affects the thermal balance of molecular clouds and with that their whole evolution .
For the first time , we study the effect of grain surface chemistry ( GSC ) on star formation and its impact on the initial mass function ( IMF ) .
We follow a contracting translucent cloud in which we treat the gas-grain chemical interplay in detail , including the process of freeze-out .
We perform 3D hydrodynamical simulations under three different conditions , a pure gas-phase model , a freeze-out model , and a complete chemistry model .
The models display different thermal evolution during cloud collapse as also indicated in , but to a lesser degree because of a different dust temperature treatment , which is more accurate for cloud cores .
The equation of state ( EOS ) of the gas becomes softer with CO freeze-out and the results show that at the onset of star formation , the cloud retains its evolution history such that the number of formed stars differ ( by 7 % ) between the three models .
While the stellar mass distribution results in a different IMF when we consider pure freeze-out , with the complete treatment of the GSC , the divergence from a pure gas-phase model is minimal .
We find that the impact of freeze-out is balanced by the non-thermal processes ; chemical and photodesorption .
We also find an average filament width of 0.12 pc ( \pm 0.03 pc ) , and speculate that this may be a result from the changes in the EOS caused by the gas-dust thermal coupling .
We conclude that GSC plays a big role in the chemical composition of molecular clouds and that surface processes are needed to accurately interpret observations , however , that GSC does not have a significant impact as far as star formation and the IMF is concerned .