Molecular Structure and Vibrational Spectra of 4-(4-Hydroxyphenylazo)phthalonitrile: DFT Study

Pogonin, Alexander E.; Kurochkin, Ivan Yu.; Malyasova, A. S.; Ksenofontova, Ksenia V.; Койфман, О. И.

doi:10.6060/mhc235113p

Cited by 1 publication

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…0.01 and ca. 0.02 Å, respectively [20]. The simulated radial distribution curves f(r) for E-AB and Z-AB differ significantly (Figure S2).…”

Section: E-ab Vs Z-ab: Capabilities Of Ged Methodsmentioning

confidence: 95%

“…This information about r e structural parameters of the "parent" molecule will be relevant for the subsequent comparison of experimentally and theoretically obtained structural parameters for substituted azobenzenes. A careful structural analysis of the parent AB is the first step toward planned studies of the gas phase molecular structure of phthalonitrile-based azodyes (e.g., [20]), in which the GED analysis will be further complicated by the need to consider tautomerism and a larger number of internal rotations. The present work also continues the studies [33][34][35][36] devoted to determining the sensitivity of the GED method to different kinds of conformational transitions caused by the rotation of various groups.…”

Section: Computational Detailsmentioning

confidence: 99%

“…However, the planarity of the E-AB structure has been the subject of controversial studies. There were several articles [14,15] describing azobenzene as a distorted molecule and many more modern works [16][17][18][19][20][21][22] proving the planar structure of the E-AB molecule. At the same time, in the crystalline state and in solutions, these molecules can undergo significant distortions [23][24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

“…[28] suggested that there are two conformers of C i and C 2 symmetries corresponding to phenyl rings rotated in the opposite and in the same direction, respectively. Vibrations corresponding to rotations of phenyl rings (A u and B g irreducible representations under C 2h point group) have frequencies of 15-21 and 95-111 cm −1 [19,20]. Potential energy surface (PES) of E-AB is shallow along the N=N-C-C torsional coordinates [19].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Comprehensive Study of Equilibrium Structure of Trans-Azobenzene: Gas Electron Diffraction and Quantum Chemical Calculations

Pogonin,

Kurochkin,

Eroshin

et al. 2024

Physchem

Self Cite

View full text Add to dashboard Cite

The geometrical re parameters of trans-azobenzene (E-AB) free molecule were refined by gas electron diffraction (GED) method using available experimental data obtained previously by S. Konaka and coworkers. Structural analysis was carried out by various techniques. First of all, these included the widely used molecular orbital constrained gas electron diffraction method and regularization method. The results of the refinements using different models were also compared—a semirigid model, three variants of one-dimensional dynamic models, and a two-dimensional pseudoconformer model. Several descriptions have been used due to the fact that E-AB has a shallow potential energy surface along the rotation coordinates of phenyl groups. Despite this, it turned out that the semirigid model is suitable for use for E-AB and allows good agreement with experimental data to be achieved. According to the results of GED structural analysis, coupled with the results of DLPNO-CCSD(T0) calculations, E-AB has a planar structure. Based only on GED data, it is impossible to unambiguously determine the rotational angle of the phenyl group due to the facts that (i) with rotation over a wide range of angles, the bonded distances in the molecule change insignificantly and (ii) potential function in a structural analysis within a dynamic model is not determined with the necessary accuracy. This work also examines the sensitivity of the GED method to structural changes caused by trans-cis isomerization. The paper also analyzes the applicability of different variants of density functional theory (DFT) calculations in GED structural analysis using E-AB as an example. There are not enough similar methodological works in the literature. This experimental and methodological information is especially important and relevant for planning and implementing GED experiments and corresponding processing of the results for azobenzene derivatives, in which the conformer and isomeric diversity are even more complicated due to the presence of different substituents.

show abstract

“…0.01 and ca. 0.02 Å, respectively [20]. The simulated radial distribution curves f(r) for E-AB and Z-AB differ significantly (Figure S2).…”

Section: E-ab Vs Z-ab: Capabilities Of Ged Methodsmentioning

confidence: 95%