We report on the resonance Raman spectroscopy of mass-selected CrFe. The molecule is isolated by sputtering a CrFe metal target, followed by mass-separation through a Wien filter. Samples are deposited in an argon matrix at 14 K. Raman spectra are obtained at several excitation wavelengths (476.5, 488.0, 496.5, 501.7, 514.5 nm) and a clear progression up to nu" = 6 is obtained. Analysis results in values of omega(c) = 166.6 +/- 0.8 cm(-1) and omega(e)x(e) = 1.1 +/- 0.1 cm(-1). This rather low frequency gives a force constant of 0.44 mdyne/Angstrom, indicating considerably weaker bonding than observed in either Cr-2 or Fe-2. (C) 2003 Elsevier Science B.V. All rights reserved.