Abstract

On the one hand, astrochemistry is sorely needed for our understanding of the physical and chemical processes, as well as the kinematics, of star forming regions, from the earliest stages (pre-stellar cores), to the switch-on of the protostar, to the formation and evolution of protoplanetary disks. On the other hand, observations of gas-phase and solid-state species in star forming regions allow us to make progresses in our understanding of astrochemistry and the production of organic molecules in space, possible seeds of life in the Universe. I shall review basic chemical processes, recent observational results and show our major achievements in understanding the physical and chemical characteristics of star forming regions and the earliest phases in the process of star formation. In particular, I shall describe the deuterium fractionation, very active in pre-stellar clouds, and recent results of a simple chemical model coupled with a radiative transfer code and constrained by observations. These results suggest that: (i) the dust in pre-stellar core nuclei (the future stellar cradles) appears to be “fluffy”, with an opacity about four times larger than that in the more diffuse interstellar medium; (ii) the cosmic ray-ionization rate cannot be significantly larger than 1×10^{-17} s-1. Main astrochemical unknowns will be outlined.