Structure and dynamics of acrolein in lowest excited ^1,3(n,π*) electronic states: The quantum‐chemical study

Abstract

Structure, conformer energy difference, and dynamics of acrolein molecule in 1,3 (n,*) electronic states were investigated by means of diverse single-and multireference quantum-chemical methods. Valence focal-point analysis of conformer energy difference in 3 (n,*) state was performed. Some reassignments of fundamentals of s-trans conformer were proposed. Internal rotation in 1,3 (n,*) states was shown to be coupled with nonplanar vibration of carbonyl fragment. Two-dimensional PES sections were constructed, and the corresponding two-dimensional vibrational problem was solved.

Vibronic spectra, ab initio calculations, and structures of conformationally non-rigid molecules of oxalyl halides in the ground and lowest excited electronic states. Part III: Theoretical investigation of oxalyl fluoride

“…Such an effect can be thought of as a strong coupling between the internal rotation and the out-of-plane CCOFwagging vibrational mode m 6 . This effect was first observed in acrolein in the 1,3 (n,p*) electronic states [49] and could be qualitatively explained by the decrease in the stability of the conjugated planar structure when the COF fragments are skewed relative to each other. With this skewed geometry, the carbonyl fragments tend to pyramidalize as in the simple carbonyls [47].…”

Vibronic spectra, ab initio calculations, and structures of conformationally non-rigid molecules of oxalyl halides in the ground and lowest excited electronic states. Part II: Theoretical investigation of oxalyl chloride

“…Such effect can be thought of as a strong coupling between the internal rotation and the non-planar CCOCl wagging vibrational mode, m 6 . Such an effect was first observed in acrolein in the 1,3 (n, pÃ) electronic states [54] and could be qualitatively explained by the disappearance of stabilization of the conjugated planar structure when the COCl fragments are skewed relative to each other. Because of this skew, carbonyl fragments tend to pyramidalize as in the simple carbonyls [52].…”

Vibronic spectra, ab initio calculations, and structures of conformationally non-rigid molecules of oxalyl halides in the ground and lowest excited electronic states. Part V: Oxalyl chloridefluoride (COCl–COF)

“…This effect is analogous to coupling found in acrolein [39], oxalyl chloride [2], and oxalyl fluoride [3] molecules in the excited electronic states of n,p* type.…”

“…Such an effect can be thought of as a strong coupling between the internal rotation and the non-planar CFO and CClO wagging vibrational modes m 10 and m 11 . This effect was first observed in acrolein in the 1,3 (n,p*) electronic states [39] and could be qualitatively explained by the disappearance of stabilization of the conjugated planar structure when the CXO fragments are skewed relative to each other. Because of this skew, carbonyl fragments tend to pyramidalize as in the simple carbonyls [38].…”