Time-resolved pump-probe stimulated-emission and transient-absorption spectra were recorded after excitation with similar to 30 fs pulses to the 1B(u)(+)(0) and optically-forbidden diabatic levels of carotenoids, neurosporene, spheroidene and lycopene having n = 9-11 double bonds, bound to LH2 antenna complexes from Rhodobacter sphaeroides G1C, 2.4.1 and Rhodospirillum molischianum. The low-energy shift of stimulated emission from the covalent 1B(u)(-)(0) and 3A(g)(-)(0) levels slightly larger than that from the ionic 1B(u)(+)(0) state suggests the polarization, whereas more efficient triplet generation suggests the twisting of the conjugated chain in Cars bound to the LH2 complexes, when compared to Cars free in solution. (c) 2009 Elsevier B.V. All rights reserved.