title: A study of pi-electron delocalization in model compounds of visual pigment by UV and carbon-13 NMR spectra.
mesh_terms: D002082:Butylamines; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D012168:Retinal Pigments; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002082:Butylamines; D012168:Retinal Pigments