The low-frequency stretching and bending vibrations of the isotopologues and have been recorded at low temperature and low resolution. For this, a cryogenic 22-pole trapping machine coupled to an IR beamline of the FELIX free electron laser facility has been used. To record the overview spectra, the laser induced reactions have been applied for these species. As this scheme is not applicable to , the latter has been tagged with He and subsequently dissociated by the IR beam. For the resulting - spectrum, broad features are observed below 1000 possibly related to vibrational motions involving the He atom. The extracted vibrational band positions for all species are compared to results from high-level quantum-chemical calculations.