Abstract—–The structure of a complex formed from retinaldehyde and ethanolamine phosphoglyceride has been proposed as a Schiff's base stabilized byπ–πinteraction between the double bond of an oleic acid group (Δ9) and the 9–10 double bond of the retinaldehyde chain. Considerations of stereochemistry and simple MO theory indicate the proposed structure to be energetically favored, and its absorption maximum is predicted by free elect