Crystal structure and theoretical studies of two π-conjugated fused-ring chalcones: (<i>E</i>)-1-(anthracen-9-yl)-3-(9-ethyl-9<i>H</i>-carbazol-3-yl)prop-2-en-1-one and (<i>E</i>)-1-(anthracen-9-yl)-3-[4-(9<i>H</i>-carbazol-9-yl)phenyl]prop-2-en-1-one
Acta crystallographica. Section E, Crystallographic communications