An NMR study of merocyanine-type dyes derived from barbituric acid

The C-13 NMR of two solvatochromic dyes derived from a barbituric acid acceptor and dimethylaminophenyl donor fragments, compound 1 and the related merocyanine 2, were recorded in various solvents. The observed chemical-shift variations were used to interpret their structural differences and solvatochromic behavior in solution. (C) 2003 Elsevier B.V. All rights reserved.