A set-up combining a high resolution Fourier transform interferometer and a quadrupole mass spectrometer with a supersonic jet expansion produced thanks to a large turbomolecular pumping unit is described. A rotational temperature close to 3 K is demonstrated. Vibration-vibration energy transfer in the expansion affecting the v(2) = 1 state in N2O is monitored in the presence of various collision partners. The transfer from the v(2) = 1 state of N2O towards the quasi resonant, lower energy v(2) = 1 state of OCS is demonstrated, in particular. (c) 2005 Elsevier B.V. All rights reserved.