CAROTENOIDS AND RELATED POLYENES .4. SYNTHESIS OF CAROTENOID ANALOGS CONTAINING A CONJUGATED CARBONYL GROUP AND THEIR FLUORESCENCE PROPERTIES

Fluorescence properties of several synthetic carotenoid analogues have been investigated in order to assess the relationship between molecul ar structures and function as a photosynthetic antenna, The origin of fluorescence is determined by two factors; the length of the conjugate d double bond system and the presence of a carbonyl group. For efficie nt energy transfer to chlorophyll a, eight conjugated double bonds and an associated carbonyl group are required, which ensures that fluores cence occurs from the S-1 state.