Infrared hole burning and crystal structures of ammonium tosylate and ammonium triflate

Spectral hole burning the N-D bands of the title compounds doped with a small amount of deuterium reveals new types of changes in the conformation in the crystals at low temperatures. Using X-ray diffraction, the crystal structure of the tosylate is determined and shows ammonium ions that are particularly strongly hydrogen bonded at one N-H. Upon hole burning, the ion pivots about this bond. The triflate forms a crystal with a number of low symmetry sites. Hole burning one type of ion causes changes in the bands that arise from the other type. The switch between different types is probably due to a reorientation of the CF3 group of the triflate ion.