The Herschel Space Observatory has opened a new observational window reaching from the far infrared to sub-millimeter wavelengths with spatial and spectral resolutions previously unmatched. The spectra obtained by Herschel reveals the presence of a large number of structures, which have been assigned to hydrides. Behind this spectra lies a rich interstellar chemistry.

Hydrides are significant reservoirs of heavy elements and thus play a central role in molecular astrophysics. Since hydrogen is far more abundant than any other element in the ISM, molecular hydrides are also the first molecules to be formed. As a result, they are sensitive markers of the interstellar chemistry networks which play an important role in modelling the evolution of molecules in the universe.

Accurate modelling of hydride emission spectra requires data for the physical and chemical processes involving these molecules that occur in the interstellar medium. Toward this end the scientific community has undertaken major efforts in recent years, both experimental and theoretical. In this workshop, we will bring together scientists from the molecular astrophysics and physical chemistry communities. There have been many studies of chemical reactions and collisional energy transfer involving hydrides. Most of this work has not been motivated by astrophysics. Exposing the chemists to the issues raised by the astrophysical community will be one goal of the proposed workshop. A second, parallel goal, will be to increase astronomers' awareness of the capabilities and limitations of the methods developed by experimental and theoretical chemists. The informality of a Telluride workshop will facilitate this cross disciplinary interaction. Similar interactions have already proven to be invaluable in the combustion community.

An important outcome will be the discussion of what new studies need to be done on modelling chemical processes involving hydride molecules and the exploration of what molecular data are currently missing that are crucially needed for astrophysical modelling.