In this talk I will show some selected results of our investigation over the last years at IEM-CSIC. First, motivated by recent identification of ammonium salts on the surface of comet 69P/C-G-C, I will present infrared spectra of NH 4 + salts on amorphous solid water, generated by hyperquenching of water solutions on cold surfaces (1). Then, I will talk about ice optical constants determination in the near and mid infrared spectral range (2). Moreover, I will show studies on infrared spectroscopy and survivability of some interstellar complex organic molecules on ices in astrophysical environments. We have provided IR spectra of glycine (3), methyl isocyanate, 2- amino-oxazole (4), and urea in ices, with the goal to help in the possible identification of these species in the solid phase with the JWST. The destruction of these molecules by the interstellar UV field or by cosmic rays were also estimated. To this aim, a D 2 UV lamp and a 5 keV electron gun were used for the derivation of the relevant destruction cross sections.