The synthesis, spectroscopic characterization and structure of three bis(arylmethylidene)cyclopentanones

Three bis(arylmethylidene)cyclopentanone dyes were synthesized and their structures and properties elucidated using single-crystal X-ray diffraction, mass spectrometry, 1H nuclear magnetic resonance, IR and UV–Vis spectroscopy. X-ray analyses revealed that two were monoclinic, with space group P21/c  , while the third dye was triclinic, with space group P1¯. All three molecules adopted an E-configuration about the central olefinic bonds, exhibiting a butterfly-shaped geometry. Molecular structure optimization using density function theory revealed that the optimized geometer parameters were in reasonably good agreement with experimental values. In addition, the highest occupied molecular orbital and lowest unoccupied molecular orbital levels were deduced.