The very weak difference bands nu(11)-nu(4) and nu(10)-nu(18) of the b
enzene molecule have been recorded by a high resolution Fourier transf
orm spectrometer equipped with a long path absorption cell. Analysis o
f the spectra yielded much improved data for the Raman active states n
u(11) (species E(1g)) and nu(18) (E(2g)), and for the inactive B-2u st
ate nu(10).