Theoretical Simulation of the Vibrationally Resolved UV Absorption Spectrum of Acryloyl Fluoride

Abstract

Acryloyl fluoride is an ideal molecule for investigating the phenomenon of hindered internal rotation. In concert with recently acquired high‐resolution UV absorption spectrum of acryloyl fluoride, in this study, the absorption spectra of the s‐trans and s‐cis isomers of acryloyl fluoride were theoretically simulated. The simulated spectra were convoluted by a Gaussian function with displacement, distortion, Franck‐Condon, Herzberg‐Teller, and Duschinsky effects in the framework of the time‐independent model. The statistical vibronic transition analysis reveals the unity of the spectrum transition property, the relevant normal modes, and the primary geometrical variations, enriching the understanding of the experimental observation. The discrepancy between the theoretical and experimental spectra was interpreted clearly.

Shape‐Persistent Macrocycles Based on Acetylenic Scaffolding

“…For example, [15]-and [14]annulenes 113-116 all form dimers in a range of solvents, but the [15] Höger and coworkers have recently observed that the free-base derivative of pyridinium SPM 122 (Figure 6.8) shows only weak aggregation in solution, forming tubular structures [98]. Once the pyridyl groups were alkylated to form the cationic species 122, however, well-defined dimers were formed, even at very low concentrations.…”

“…Likewise, the use of acetylenic SPMs in functional systems has also been reviewed, but, again, typically with respect to a particular molecular design [5,[14][15][16]. In view of previous literature in this area, the goal of this particular chapter will be to integrate the two aspects.…”

“…The selectivity is demonstrated in the formation of bis [15]-and bis [14] annulenes (25,26 and 27,28) shown in Scheme 6.9, several derivatives of which were explored for self-association (see Figure 6.4). Briefly, it was shown that intramolecular homocoupling of 29 or 30 under Eglinton conditions gave preferentially the bis [15]annulenes 25 and 26.…”

“…This selectivity was ascribed to the nature of the dimeric Cu-acetylide intermediate, which, prior to reductive elimination, is commonly assumed to adopt a pseudo-trans-configuration (Scheme 6.9, inset a). Molecular modeling showed that such an intermediate geometrically favors the formation of the less strained [15]annulenes over the more strained [14]annulenes. Conversely, use of Pd-catalyzed homocoupling conditions with 29 or 30 results in selective formation of the bis [14]annulenes 27 and 28.…”

“…Molecular modeling showed that such an intermediate geometrically favors the formation of the less strained [15]annulenes over the more strained [14]annulenes. Conversely, use of Pd-catalyzed homocoupling conditions with 29 or 30 results in selective formation of the bis [14]annulenes 27 and 28. In this case, the cis-configuration of the Pd-diacetylide intermediate, prior to reductive elimination, is presumably enforced by the chelating bidentate dppe ligand (Scheme 6.9, inset b), and this factor ultimately leads exclusively to formation of the more strained products 27 and 28.…”