Two-dimensional potential energy function for internal rotation in 1,2-dihydroxybenzenes

Shundalov, M. B.; Pitsevich, G. А.; Ksenofontov, M. A.; Umreiko, D. S.

doi:10.1007/s10812-006-0050-z

Cited by 4 publications

(4 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Relatively little work has been published on vibrational PESs outside our laboratory in recent years, although a number of papers have appeared on the study of internal rotations. − Several of our recent studies have focused on determining two-dimensional PESs for bicyclic molecules in order to better understand how the two rings interact. We are aware of only one report of a two-dimensional PES from another laboratory . In 2004 we presented our study of bicyclo[3.3.0]oct-1,5-ene (BCO) and showed that its PES could be represented by a function of the form V = a ( x 1 4 + x 2 4 ) + b ( x 1 2 + x 2 2 ) + c x 1 2 x 2 2 + d x 1 x 2 where x 1 and x 2 are the ring-puckering coordinates of the two rings and a , b , c , and d are potential energy parameters that are determined so that they best fit the two different conformational energies and energy barriers found from ab initio calculations.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Vibrational Spectra, Theoretical Calculations, and Two-Dimensional Potential Energy Surface for the Ring-Puckering Vibrations of 2,4,7-Trioxa[3.3.0]octane

Chun

Meinander

Villarreal³

et al. 2014

J. Phys. Chem. A

View full text Add to dashboard Cite

2,4,7-Trioxa[3.3.0]octane (247TOO) is an unusual bicyclic molecule which can exist in four different conformational forms which are determined by the directions of the two ring- puckering motions. The vibrational assignments of 247TOO have been made based on its infrared and Raman spectra and theoretical density functional theory (DFT) calculations. The two ring-puckering motions (in-phase and out-of-phase) were observed in the Raman spectra of the liquid at 249 and 205 cm(-1) and these values correspond well to the DFT values of 247 and 198 cm(-1). Ab initio calculations were utilized to calculate the structures and conformational energies for the four energy minima and the barriers to interconversion and the data was utilized to generate a two-dimensional potential energy surface (PES) for the two ring-puckering motions. The resulting quantum state energies for this PES were then calculated in order to better understand the patterns that are produced when the PES has four energy minima at different energy values. The wave functions corresponding to the different quantum states were also calculated. The NMR spectrum of 247TOO showed the presence of the two lowest energy conformations, consistent with the results of the ab initio calculations.

show abstract

Section: Introductionmentioning

confidence: 99%

“…We are aware of only one report of a twodimensional PES from another laboratory. 16 In 2004 we presented our study of bicyclo[3.3.0]oct-1,5-ene 17 (BCO) and showed that its PES could be represented by a function of the form…”

Section: ■ Introductionmentioning

confidence: 99%

Vibrational Spectra, Theoretical Calculations, and Two-Dimensional Potential Energy Surface for the Ring-Puckering Vibrations of 2,4,7-Trioxa[3.3.0]octane

Chun

Meinander

Villarreal³

et al. 2014

J. Phys. Chem. A

View full text Add to dashboard Cite

show abstract

“…Thus the contributions of the cross term ∂ 2 ⁄ ∂g 1 ∂g 2 and the first derivatives ∂ ⁄ ∂g 1 and ∂ ⁄ ∂g 2 are small and can then be taken into account by perturbation theory, while the kinetic part of Hamiltonian (2) allows for separation of variables. The potential energy function for internal rotation can be represented in the form [7]:…”

mentioning

confidence: 99%

Calculation of the energies of torsional states for dihydroxybenzenes

et al. 2007

Self Cite

View full text Add to dashboard Cite

We present theoretical models and results of calculations of the energies of torsional states of dihydroxybenzenes: flexible molecules with two non-coaxial internal tops of low symmetry.Introduction. Dihydroxybenzenes (dihydric phenols), containing a six-membered ring in their molecules, are aromatic compounds widely distributed in nature and used for practical purposes. Thus dihydroxybenzenes are included as a basic structural unit in gas-filled polymers (foam plastics) which, owing to their unique combination of low density and high strength with exceptionally good soundproofing and thermal insulation properties, have been widely used in various areas of human activity [1].The properties of dihydroxybenzenes vary depending on the relative positions of the OH groups (1,2-, 1,3-, or 1,4-substitution), which also affects the properties of the final product (the polymer). The relative positions of the OH groups also has a substantial effect on the torsional spectra of the dihydroxybenzenes resulting from internal rotations of the hydroxyl groups relative to the core of the molecule (the benzene ring).Spectral structural analysis of dihydroxybenzenes and their derivatives has mainly been carried out with respect to the fundamental vibrational frequencies [2]. Until recently, there was virtually no proper attention paid to the problem of calculating and interpreting the high-resolution torsional spectra, lying in the far IR and microwave regions, for flexible molecules with two non-coaxial internal tops. The major approaches making it possible to calculate the energy states for multi-dimensional torsional motion do not differ in principle from the one-dimensional case [3,4]. However, their application at the moment is limited to compounds containing highly symmetric internal tops (with a three-fold symmetry axis) [5], because the mathematical apparatus needed for the calculation becomes considerably more complicated when going to a two-dimensional model.In this paper, we present the results of a theoretical calculation of the energies of the torsional states of 1,2-, 1,3-, and 1,4-dihydroxybenzene molecules, taking into account interaction between the hydroxyl groups.Procedure. The rotational-torsional Hamiltonian (in cm -1 ) of a flexible molecule with two internal tops has the form [4]:

show abstract

“…To model the torsional IR and Raman spectra of hydroquinone, the following values were selected for the potential energy function to internal rotation [32]: V 0 = 1100-2000, V 1 = V 3 = 800-1000, V 2 = 1000-1900, V 4 = V 5 = 10-50 cm -1 . One variant of the torsional potential function for hydroquinone is given in Fig.…”

mentioning

confidence: 99%

Calculation of transition intensities for torsional vibrations in IR and Raman spectra of dihydroxybenzenes

et al. 2007

Self Cite

View full text Add to dashboard Cite

show abstract

Two-dimensional potential energy function for internal rotation in 1,2-dihydroxybenzenes

Abstract: We have obtained an analytical expression for the two-dimensional potential energy function for internal rotation in 1,2-dihydroxybenzenes, allowing us to use perturbation theory methods to calculate and interpret the torsional spectra of these compounds.

Cited by 4 publications

References 10 publications

Vibrational Spectra, Theoretical Calculations, and Two-Dimensional Potential Energy Surface for the Ring-Puckering Vibrations of 2,4,7-Trioxa[3.3.0]octane

Vibrational Spectra, Theoretical Calculations, and Two-Dimensional Potential Energy Surface for the Ring-Puckering Vibrations of 2,4,7-Trioxa[3.3.0]octane

Calculation of the energies of torsional states for dihydroxybenzenes

Calculation of transition intensities for torsional vibrations in IR and Raman spectra of dihydroxybenzenes

Contact Info

Product

Resources

About