The (CP)(2)Fe+ (CP = eta(5)-C5H5) cations have been obtained in surprisingly high yield by resonance two-colour multiphoton excitation of ferrocene in a jet-cooled molecular beam with tunable nanosecond lasers. The intermediate electronic levels lie in the region of the lowest Rydberg p absorption band. The ion excitation spectrum reveals resolved vibronic structure of the 3d(z)2 --> R4(x,y) transition. The distance between the vibronic components (320 cm(-1)) corresponds to the metal-ligand stretching frequency in the Rydberg state. (C) 2002 Published by Elsevier Science B.V.