Crystal structure of 3-(3-oxo-3-naphthyl-propenylamino)-1-naphthyIprop- 2-en-l-one, C26H19NO2 and of 1-{(4,4-dimethyl)3-oxopent-1-enylamino}-4,4-dimethyl-pent-1-en-3-one, C14H23NO2, two bisacylvinylamines with bifurcated hydrogen bonding - Imgartinger H.; Oeser Τ.; Dabrowski J. (Zeitschrift für Kristallographie - New Crystal Structures, 2001)